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Epidemiology Of Oral Diseases Definitions

Epidemiology

• Epidemiology is defined as the study of the distribution and determinants of health-related states or events in specified populations and the application of this study to the control of health problems

Dental caries

• Dental caries is defined as an infectious, microbiologic disease of the teeth that results in localized dissolution and destruction of the calcified tissues

Epidemiology Of Oral Diseases Important Notes

1. Diet studies related to dental caries

• Vipeholm study
• Hopewood House study
• Turku sugar study
• Hereditary fructose intolerance
• Tristan da Cunha’s study

2. Vipeholm study

• Described by Gustaffson et al in 1954 and summarized by Davies in 1955

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Vipeholm Method:

• The institutional diet was nutritious but contained little sugar with no provision for between meals
• 4 meals were eaten daily
• 7 groups were obtained
  • Control group
  • Sucrose group
  • Bread group
  • Chocolate Group
  • Caramel Group
  • 8 toffee group
  • 24 toffee group

Vipeholm Conclusion:

• An increase in carbohydrate intake increases dental caries
• Retentive sugar items cause an increase in dental caries
• Sugar consumed in between meals causes dental caries
• Increase in caries activity varies between individuals
• Withdrawal of sugar items causes the disappearance of increased caries activity
• A high concentration of sugar in solution & its prolonged retention leads to increased caries activity
• An increase in clearance time of sugar increases caries activity

Epidemiology Of Oral Diseases Questions And Answers

3. Hopewood house study

• Investigators are Harris and Sullivan
• The dental status of children between 7-14 years of age residing at Hopewood House, Bowral, New South Wales was studied longitudinally for 10 years
• The absence of meat and the rigid restriction of refined carbohydrates are two important features of the study

Hopewood house Result:

• At the end of 10 years

Hopewood House Conclusion:

• In institutionalized children dental caries can be reduced by a restricted carbohydrate diet even in the presence of unfavourable oral hygiene

4. Turku sugar study

• Investigators are Scheinin and Makinen et al
• Investigated the effect of sucrose, fructose and xylitol on caries development

Turku sugar Conclusion:

• Sucrose – highly cariogenic
• Fructose – cariogenic as sucrose for the first 12 hours but less at the end of 24 hours
• Xylitol – anti-cariogenic with 85% reduction in dental caries

5. Tristan

• Investigator is Fisher
• He carried dental examinations in 1932,1937, and 1953 on the island and again in England in 1962 and 1966 in the island when the people of Tristan de Cunha returned to their island from England

Tristan Results:

• In 1932 and 1937 – 0% of caries
• In 1962-50%
• In 1966-80%

6. Hereditary fructose intolerance

• It is due to reduced levels of enzyme fructose-l-phosphate aldolase required for the metabolism of sucrose or fructose
• Persons affected by it avoid food containing fructose or sucrose because ingestion of these foods causes nausea, vomiting, excessive sweating and even coma.

7. Predictors of high caries risk are

• Multiple new lesions
• Multiple restorations
• History of premature extraction for caries
• Anterior teeth caries or restoration
• History of frequent replacement of restoration

8. Frequent intake of sucrose for at least 60-100 minutes/day is associated with the formation of rampant caries

Oral Diseases Epidemiology

Epidemiology Of Oral Diseases Long Essays

Question 1. Define epidemiology. Describe the epidemiological factors of oral cancer.
Answer:

Epidemiology Definition:

It is defined as the study of the distribution & determinants of health-related states or events in specified populations and the application of this study to the control of health problems

Epidemiological Factors Of Oral Cancer:

Host:

• Age:
  • Older people show an incidence of carcinoma
  • Younger people show an incidence of sarcoma
• Race:
  • Whites develop lip melanoma more frequently
• Sex
  • Carcinoma of the lip common in women
  • Cancer of the tongue & buccal mucosa common in males
• Genetic factors
  • Oncogenes involved in the initiation & progression of malignancy
• Occupation
  • Textile workers show an increased incidence of oral cancer

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• Immunity
  • Kaposi sarcoma common in AIDS patient
• Social class
  • Low-income group shows an increase in cancer of the oral cavity
• Customs & Habits
  • Smoking increases the incidence of cancer

Agent:

• Biological
  • Virus
  • Fungi
• Chemical
  • Arsenic
  • Dyes
  • Nickel
  • Aromatic amines
• Mechanical
  • Sharp tooth
  • fitting dentures
  • Jagged teeth
• Nutritional agents
  • Precarcinogens
  • Increased consumption of fat
  • Deficiency of folic acid
  • Protein deficiency
  • Increased consumption of red chilli powder
  • Decrease in copper, zinc, vegetable, vitamin C, E

Environmental:

• Water contaminants
  • Includes some organic pollutants like chloroform
• Air pollution
  • Caused by the release of several gases from automobiles & factories
• Geographic variation
  • In the Netherlands: buccal mucosa is most affected
  • In Switzerland: the lip & tongue are most affected
  • In Canadian Eskimos: cancer of the salivary gland is more common
  • In Srikakulam & Vishakapatnam: palatal cancer is the most common
• Solar heat
  • Prolonged exposure to sunlight causes melanoma
• Industrialization
  • The release of various toxins by the industries contaminates water & lead to cancer

Epidemiology Of Dental Caries

Question 2. Epidemiology of periodontal disease.
Answer:

Epidemiology of periodontal disease Agent:

Dental plaque:

• Dental plaque is a primary etiological factor for periodontal disease
• Dental plaque is defined as a structured, resilient, yellow-greyish substance that adheres tenaciously to the intraoral hard surfaces, including removable & fixed restoration
• Dental plaque is composed of bacteria in a matrix of salivary glycoprotein & extracellular polysaccharides
• Dental plaque is because of this matrix, it cannot be removed by rinsing
• Classified into
  • Supragingival plaque: at or coronal to marginal gingiva
    • It is responsible for gingivitis
  • Subgingival plaque: apical to gingival margin
    • It is responsible for calculus & root caries
  • Accumulation of plaque is found more on the gingival l/3rd of the tooth surfaces, cracks, pits & fissures, overhanging restoration & around malaligned teeth

Calculus:

• Calculus is a hard deposit that forms by mineralization of dental plaque & is usually covered by a layer of unmineralized plaque
• Calculus is classified into
  • Supragingival calculus
  • Located coronal to the gingival margin
  • Calculus is white or whitish-yellow
  • Calculus has a hard, clay-like consistency
  • Calculus can be easily detached from the tooth
• Subgingival calculus
  • Subgingival calculus is located below the crest of the marginal gingiva
  • Subgingival calculus is a dark brown or greenish black
  • Subgingival calculus is hard & dense
  • Subgingival calculus is firmly attached to the tooth structure
• Calculus provides a fixed nidus for the continued accumulation of plaque

Host Factors:

• Age
  • The prevalence of periodontal disease increases with age due to the cumulative progression of the lesions over time
• Gender
  • Based on epidemiological studies, the prevalence & severity is higher in males than in females
• Socio economic status
  • Lower socioeconomic status results in poor diet, poor oral hygiene & a general lack of dental awareness
  • Whereas those who are well-educated, wealthier & live in better circumstances visit dentists frequently
  • Thus periodontal disease prevalence increases in low socioeconomic status
• Diet & Nutrition
  • Sticky foods adhere to the teeth & are difficult to remove thus interfering with the natural cleansing mechanism and leading to periodontal disease
  • The nutrients associated with periodontal tissues are vitamin A, B complex, C, D, calcium & phosphorous
  • Prevalence & severity of periodontal disease increases in protein malnutrition & vitamin A deficiency
• Anatomy
  • The normal contour of the tooth protects the underlying tissues
  • Tooth
    • Sharp cusps, uneven marginal ridges, lack of contact between teeth & crowding can cause food impaction
• Soft tissue
  • When the frenum is inserted close to the marginal gingival, the pull of attachment may cause recession of the papilla along with interfering with the proper use of the toothbrush
• Habits
  • Thread biting, holding nails between teeth, bruxism, lip, cheek & nail biting can cause traumatic effects on the periodontium
• Local irritants
  • Mechanical
    • Faulty tooth brushing causes abrasion or recession of the gingival tissues
    • Faulty restoration impinges on gingival & irritates them
    • Faulty orthodontic treatment results in root resorption as well as alveolar bone loss & Mobility
• Chemical
  • Alcohol, tobacco & condiments lower tissue resistance & increase susceptibility to gingivitis & periodontitis
  • Atmospheric lowers the tissue resistance
• Systemic factors
  • Systemic diseases act locally to reduce the resistance to periodontal destruction & the local periodontal pathogens act systemically to produce an impact on the general health

Epidemiology of periodontal disease Environmental Factor

Geographic variation:

• Nutrition:
  • Avitaminosis C, Niacin deficiency shows an increased prevalence of periodontal disease
  • Increased prevalence of periodontal disease was found in areas with protein malnutrition & vitamin A Deficiency
• Degree of urbanization
  • Rural areas may have an increased prevalence than urban areas
  • It can be due to oral hygiene practices, diet & socioeconomic status
• Psychological & cultural factors
  • Stress predisposes to ANUG
  • Certain cultures view dental problems & loss of teeth solely as an ageing process

Periodontal Disease Epidemiology

Question 3. What is an epidemiological triad? Discuss the role of components of an epidemiological triad in dental caries.
Answer:

Epidemiological Triad:

• The occurrence of any disease is determined by the interaction between the agent, host and environment constituting an epidemiological triad

Components In Dental Caries:

1. Host factor:

• Tooth

Composition:

Morphology:

• That predisposes to dental caries are deep, narrow, occlusal fissures, buccal & lingual pits
• Disturbed clarification

Position:

• Malaligned & rotated predispose to caries

Saliva:

• Removes bacteria & food debris through its flushing action

pH:

• Saliva is slightly acidic
• As the flow rate increases pH also increases

Viscosity:

• As viscosity increases caries activity increases

Sex:

• Caries are more common in females

Race:

• Caries are more common in whites

Age:

• Root caries common in older individuals

1. Familial hereditary
   • Inheritance of a characteristic tooth structure
2. Developmental disturbances
   • The presence of deep pits and fissures, enamel hypoplasia and enamel defects more prone to caries
3. Economic status
   • In young individuals, caries decreases with an increase in income
   • In adults, as income decreases, dental caries decreases
4. Concomitant disease
   • Fewer caries in controlled diabetes
5. Oral hygiene habits
   • Fewer caries in those who maintain good oral hygiene

2. Microflora:

• Streptococcus mutans are responsible for early carious lesions
• Lactobacilli are associated with dentinal caries and
• actinomyces strains with root surface caries

3. Local substrate diet:

• It depends on

1. Physical Properties of Food and Cariogenicity
   • Physical properties that improve the cleansing action reduce the retention of food within the oral cavity and increase saliva flow are caries-preventive
2. Sucrose
   • It is responsible for caries development
3. Vitamin K
   • Has the possible anticaries agent
4. Vitamin B complex
   • Alters oral flora by promoting the growth of non-cariogenic organisms
5. Calcium and phosphorous dietary intake
   • Disturbance in calcium and phosphorous metabolism during the period of tooth formation may result in severe enamel hypoplasia and defects of the dentin
6. Fluoride in diet

• • Fluoride prevents dental caries

Oral Cancer Epidemiology

Epidemiology Of Oral Diseases Short Essays

Question 1. Role of tobacco in oral health.
Answer:

Role of tobacco in oral health

• Tobacco is a major contributor to oral disease
• Tobacco use
  • Slows wound healing after dental surgery
  • It promotes periodontal disease
  • Halitosis
  • Oral infections
  • Causes cancer of the oral cavity & tongue, larynx, pharynx, oesophagus, stomach, lung
• Smokeless tobacco causes oral cancer
• Chewing of paan is a major cause of oral & oesophageal cancer
• Smoking is a known cause of cardiovascular disease
• Exposure to non-smokers causes respiratory disease, worsening of asthma
• Tuberculosis is more common in smokers
• Mortality increases
• Pregnant women exposed to passive smoking may deliver lower birth-weight babies
• Its consequence may be babies with cleft lip & palate
• Men who smoke or use smokeless tobacco may develop reduced fertility & sexual impotence

Question 2. Prevention of oral cancer.
Answer:

Prevention of oral cancer

• Prevention of oral cancer mainly focuses on modifying habits associated with the use of tobacco
• There are 3 well-known approaches
  • Regulatory approach
    • Print warning on cigarette packets
    • In 2003, prohibition was made on advertisement of & to provide for the regulation of production, supply & distribution of cigarettes & other tobacco production
• Service approach
  • The active search for disease among apparently healthy people
• Educational approach
  • Dentists help patients to quit tobacco by promoting tobacco prevention & control strategies

Counselling For Tobacco Cessation (5a’s):

• Ask:
  • Ask the patient about tobacco use at every visit
• Advice
  • Non-smokers to never use tobacco smokers to quit
• Assess
  • The level of dependence
• Assist
  • Quitting by setting a firm quit date
• Arrange
  • For follow-up/recall visits

Use Of Pharmacotherapy:

• Nicotine replacement therapies
  • Nicotine gum
  • Nicotine patch
  • Nicotine inhaler
  • Nicotine nasal spray
  • Nicotine lozenges
• Anti .depressants
• First line therapies
• Buproprion SR
• Selegiline
• Second line therapies
• Clonidine
• Nortriptyline

Counselling Those Unwilling To Quit (5r’s):

• Relevance of quitting
• Risks of continuing tobacco use
• Rewards of quitting
• Roadbacks to quitting
• Repeat these at each level

Common Oral Diseases And Prevention

Question 3. Oral submucous fibrosis.
Answer:

Oral submucous fibrosis

• Oral submucous fibrosis is a pre-cancerous condition
• Oral submucous fibrosis is characterized by juxta epithelial inflammatory reaction in the oral mucosa followed by a fibro elastic transformation of the lamina propria leading to mucosal atrophy, rigidity & trismus

Aetiology:

• Consumption of red chillies
  • Consumption of areca nuts
  • Nutritional deficiencies
  • Immunological factors
  • Genetic factors

Features:

• Burning sensation
  • Difficulty in mastication
  • Referred pain in the ear
  • Depapillation of tongue
  • Restricted movement of the floor of the mouth
  • Shrunken uvula
  • Fibrous bands
  • Restricted mouth opening
  • Stiffness of buccal mucosa

Management:

• Quit the habit
  • Antioxidant- Oxyace-1 capsule/ day
  • Multivitamin therapy
  • Steroid- Betnovate 0.12%
  • Tumeric application
  • Intralesional injection of Hyaluronidase- 1500 U
  • Physiotherapy
  • Splitting of fibrous bands
  • Laser

Question 4. Antibacterial property of saliva.
Answer:

Antibacterial properties of saliva

Epidemiology Of Oral Diseases Short Question And Answers

Question 1. Stephen’s curve.
Answer:

Stephen’s curve

• Stephan showed that within 2-4 minutes of rinsing with a solution of glucose/ sucrose, plaque pH is reduced from 6.5-5
• Stephen’s curve gradually returns to the original value within approximately 40 minutes
• Graphical presentation of it gives Stephan a curve

Epidemiology Of Oral Health

Question 2. Sugar substitutes.
Answer:

Sugar substitutes

Question 3. Constituents of Cigarette smoke
Answer:

Constituents of Cigarette smoke

Question 4. Reverse smoking.
Answer:

Reverse smoking.

Cigarette

• Tobacco is smoked with a lighted end inside the mouth
• Air reaches the burning side through the unlighted end
• Smoke is expelled through the cigarette/ mouth

Chutta

• The smoker lights the chute
• Draws a few puffs conventionally
• Chutta is rarely taken out

Places

Side Effects:

• The temperature of the palatal mucosa increases to 58 degrees C
• Palatal patches exhibiting malignancy

Question 5. Smoking form of tobacco.
Answer:

Smoking form of tobacco

1. Bidis

• About 0.2-0.3 gms of sundried tobacco flakes are hand-rolled in a rectangular piece of tempura or tendu leaf and tied with a thread

2. Chillum

• It is a straight, 10-14 cm long conical clay pipe

3. Chutta

• It is a cylindrical coarsely prepared cheroot

4. Cigarettes

• About 1 gm of tobacco cured in the sun or artificial heat is covered with papers

5. Dhumti – conical carrots

• Hookah – water pipe
• Hookli
• Clay pipe of about 7-10 cm with mouthpiece and bowl

Risk Factors For Oral Diseases

Epidemiology Of Oral Diseases Viva Voce

1. Miller proposed the chemical-parasitic theory of dental caries
2. Clark observed a higher number of Streptococcus mu- tans are found at various site
3. The two most important risk factors associated with oral cancer are tobacco and alcohol
4. Hookah is also called water pipe or hubble-bubble
5. No tobacco day is observed on 31st May.
6. Anticancer drug busulfan is an alkylating agent
7. Dhumti is used for reverse smoking in women
8. Masheri is used to clean the teeth

Epidemiological Methods Definitions

Epidemiology

• Epidemiology is defined as the study of the distribution & determinants of health-related states or events in specified populations and the application of this study to the control of health problems

Incidence

• Incidence is defined as the number of new cases of a specific disease occurring in a defined population during a specified time

Prevalence

• The total number of all individuals who have an attribute or disease at a particular time divided by the population at risk of having the attribute or disease at this point in time or midway through the period

Matching

• Matching is defined as the process by which we select controls in such a way that they are similar to cases with regard to certain pertinent selection variables which is known to influence the outcome of the disease and which if not adequately matched for comparability could distort or confound the results.

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Cohort

• A cohortis defined as a group of people who share a common characteristic or experience within a defined time period

Epidemic

• It is an unusual occurrence in a community or region of disease, specific health-related behavior, or other health-related events clearly in excess of excepted occurrence.

Epidemiological Methods Questions And Answers 

Pandemic

• A pandemicis an epidemic usually affecting a large proportion of the population and occurring over a wide geographic area such as a nation, a continent, or a world

Attributable risk

• Attributable risk is the difference in incidence rates of disease between an exposed group and a nonexposed group

Endemic

• Endemic is the constant presence of a disease or infectious agent within a given geographic area or population group without importation from outside.

Epidemiological Methods Important Notes

1. Classification of epidemiology:

• Descriptive
• Analytical
  • Ecological study
  • Cross-sectional
  • Case-control
  • Cohort study
• Experimental

2. Types of study

3. Odds ratio

• Odds ratio is an indirect method of estimating the relative risk
• Odds ration = \(\frac{\begin{array}{c}\text { Exposed with disease } \times \\\text { unexposed without disease }\end{array}}{\begin{array}{c}\text { Exposed without disease } \times \\\text { unexposed with disease }\end{array}}\)
• The odds ratio is used for case-control studies
• The odds ratio takes a value between zero to infinity.
• Derived from case-control studies
• An odds ratio of 2.25 means that the risk of oral cancer is 2.25 times higher in people who smoke than those who do not smoke

4. Blinding is done to reduce bias

• Blinding is done to reduce bias can be done in 3 ways

1. Single-blind trial
   • Single-blind trial is so planned that the participants are not aware whether they belong to the study group or control group
2. Double-blind trial
   • Double-blind trial is so planned that neither the doctor nor the participants know to which group of patients are given drugs and which group is given a placebo
   • Double-blind trial is the most frequently used method of blinding.
3. Triple blind trial
   • In this, the participant, investigator, and the person analyzing the data are all blind

5. Tools of measurement in epidemiology

• Rates – It is the frequency of a disease expressed per unit size of a population or group in which it is observed.
• Ratio – Denotes the relation in size between two random quantities
• Proportions – it is a ratio that expresses the relation in the magnitude of art of the whole. Expressed in percentage.

6. Principles of epidemiology

• Exact observation
• Correct interpretation
• Rational explanation
• Scientific construction

7. Basic measurements in epidemiology

• Measurement of mortality
• Measurement of morbidity

8. Epidemiological methods

• Descriptive epidemiology
• Analytical epidemiology
• Experimental epidemiology

9. Attributable risk

• Derived from a cohort study
• Expressed as percentage
• Indicates to what extent the disease under study can be attributed to exposure.

Observational Studies In Epidemiology

10. Relative risk

• Relative risk is the ratio between incidence among exposed and incidence among non-exposed
• Relative risk is a direct measure of the strength of the association.

11. Various terms

Epidemiological Methods Long Essays

Question 1. Define epidemiology. Write about its principles. Discuss briefly the agent and host factor in periodontal disease.
Answer:

Epidemiology Definition:

Epidemiology is defined as the study of the distribution & determinants of health-related states or events in specified populations and the application of this study to the control of health problems

Epidemiology Principles:

• Exact observation- strict, vigorous, accurate, precise
• Correct interpretation- free from error
• Rationale explanation- intelligent, sensible
• Scientific construction- by expert knowledge & technical skill

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Epidemiology Of Periodontal Disease:

Epidemiology Agent:

• Dental plaque
  • Dental plaque is a primary etiological factor for periodontal disease
  • Dental plaque is defined as a structured, resilient, yellow-grayish substance that adheres tenaciously to the intraoral hard surfaces, including removable and fixed restoration
  • Dental plaque is composed of bacteria in a matrix of salivary glyphosate in and extracellular polysaccharides
  • Dental plaque is because of this matrix, that it cannot be removed by rinsing
• Classified into
  • Supragingival plaque: at or coronal to marginal gingiva
  • The agent is responsible for gingivitis
  • Subgingival plaque: apical to gingival margin
    • The agent is responsible for calculus & root caries
• Accumulation of plaque is found more on the gingival 1/3rd of the tooth surfaces, cracks, pits, and fissures, over-hanging restoration & around malaligned teeth
• Calculus
  • Calculus is a hard-to deposit that forms by mineralization of dental plaque and is usually covered by a layer of unmineralized plaque
  • Calculus is classified into
• Supragingival calculus
  • Located coronal to the gingival margin
  • Supragingival calculus is white or whitish-yellow
  • Supragingival calculus has a hard, clay-like consistency
  • Supragingival calculus can be easily detached from the tooth
• Subgingival calculus
  • Supragingival calculus is located below the crest of the marginal gingiva
  • Supragingival calculus is a dark brown or greenish black
  • Supragingival calculus is hard and dense
  • Supragingival calculus is firmly attached to the tooth structure
• Calculus provides a fixed nidus for the continued accumulation of plaque

Epidemiology Host Factors:

Age:

• The prevalence of periodontal disease increases with age due to the cumulative progression of the lesions over time

Gender:

• Based on epidemiological studies, the prevalence and severity are higher in males than in females

Race:

• Blacks are more affected than the whites

Epidemiology Socioeconomic Status:

• Lower socioeconomic status results in poor diet, poor oral hygiene, and a general lack of dental awareness
• Whereas those who are well-educated, wealthier, and live in better circumstances visit dentists frequently
• Thus periodontal disease prevalence increases in low socioeconomic status

Epidemiology Diet And Nutrition:

• Sticky foods adhere to the teeth and are difficult to remove thus interfering with the natural cleansing mechanism and leading to periodontal disease
• The nutrients associated with periodontal tissues are vitamin A, B complex, C, D, calcium, and phosphorous
• Prevalence and severity of periodontal disease increases in protein malnutrition and vitamin A deficient

Epidemiology Anatomy:

• The normal contour of the tooth protects the underlying tissues

Epidemiology Tooth:

• Sharp cusps, uneven marginal ridges, lack of contact between teeth, and crowding can cause food impaction

Epidemiology Soft Tissue:

• When the frenum is inserted close to the marginal gingival, the pull of attachment may cause recession of the papilla along with interfering with the proper use of a toothbrush

Epidemiology Habits:

• Thread biting, holding nails between teeth, bruxism, lip, cheek, and nail-biting can cause traumatic effects on the periodontium

Epidemiology Mechanical:

• Faulty toothbrushing causes abrasion or recession of the gingival tissues
• Faulty restoration impinges on gingival and irritates them
• Faulty orthodontic treatment results in root resorption as well as alveolar bone loss and Mobility

Epidemiology Chemical:

• Alcohol, tobacco, and condiments lower tissue resistance and increase susceptibility to gingivitis and periodontitis

Epidemiology Atmospheric:

• Because of obstruction in the nasal passage patient breath from the mouth leading to dehydration of the mucous membrane
• Atmospheric lowers tissue resistance

Epidemiology Systemic factors:

• Systemic diseases act locally to reduce the resistance to periodontal destruction and the local periodontal pathogens act systemically to produce an impact on the general health

Descriptive And Analytical Epidemiology

Question 2. Describe in brief the types of epidemiology studies.
Answer:

Types Of Epidemiological Studies:

Descriptive Epidemiology:

• Descriptive Epidemiology is usually the first step in an epidemiological study
• Descriptive Epidemiology is concerned with the observation of the distribution of the disease or any health-related events in the human population and the identification of the characteristics with which the disease or condition under study seems to be associated
• Descriptive Epidemiology is used for the quantification of the disease status of the community
• The steps involved in it are
  • Defining the population to be studied
  • Defining the disease under study
  • Describing the disease in terms of
    • Time
    • Place
    • Person
• Measurement of the disease
• Compared with known indices
• Formulating an etiological hypothesis

Analytical Epidemiology:

• The focus here is the individual within the population
• Analytical Epidemiology is designed primarily to establish the causes of disease by investigating the association between exposure to a risk factor and the occurrence of disease
• The objective is to test the hypothesis
• Types
  • Case-control study
  • Cohort study

Experimental Epidemiology:

• Experimental Epidemiology is carried out under the direct control of the investigator
• Experimental Epidemiology involves some actions, interventions,s or manipulation in the experimental group while making no change in the control group
• Next, compare the outcome of the experiment in both groups
• Types
• Randomized controlled trials
• Non-randomized trials

Question 3. Describe the uses of epidemiology.
Answer:

Uses Of epidemiology:

• Community Diagnosis
  • This consists of the collection, description, and analysis of information on the occurrence and distribution of disease in the population about characteristics of the agent, host, and environment
  • The importance of the disease is usually determined by the extent of the incidence, prevalence, and mortality by age, sex, race, nativity, marital status, geographic area, temporal variation, and socioeconomic status
• Rise and fall of the disease
  • It is done through repeated evaluation of the health care related matters
  • Due to this, some diseases pale out in history while new ones emerge
  • The seasonal nature of the disease may be revealed
• Planning and Evaluation
  • Planning is essential for a rational allocation of limited resources
  • Evaluation is done to find out whether the measures undertaken to prevent disease are effective in reducing the frequency of the disease
• Evaluation of individual risk
  • The purpose of this is to estimate the probable chances that certain types of individuals will, under certain conditions, suffer from specific illnesses, de- fects, or accidents
  • It is also an estimate of the probabilities of life and death expectancy

Question 4. Describe steps in descriptive epidemiology.
Answer:

Steps In Descriptive Epidemiology:

Defining The Population to Be Studied:

• The population has to be defined in terms of the total number and the composition of the individuals within the population in terms of characteristics such as age, sex, occupation, culture, socio-economic status
• The defined population can either be the total population in a geographic area or a representative sample taken from the population
• The defined population provides a denominator for calculating rates
• The population of the community selected for the study should always remain stable, without any migration into or out of the area

Defining The Disease Under Study:

• It should be precise and valid to enable the investigator to identify those who have the disease from those who do not
• The disease needs to be defined with an operational definition which is a definition with which the disease or condition can be identified and measured in the fined population with a degree of accuracy
• The diagnostic methods adopted for the study should be acceptable and applicable to the population to be studied

Describing the Disease Under Study:

This step is used to describe the occurrence and distribution of the disease by the time of its occurrence, the place of occurrence, and the persons who are affected by the disease

1. Time Distribution:

• Time may be measured in terms of hours, days, weeks, months, years, etc.

Time Distribution Types:

• Short-term fluctuation ex. Epidemic
• Common source epidemic
  • A single exposure or point source epidemic. Ex. Food poisoning
• Continuous or multiple exposure. Ex. Contaminated water
  • Propagated epidemic
• Person-to-person transmission
• Arthropod vector
• Animal reservoir
  • Periodic fluctuation
    • Seasonal trends: example: Measles and varicella
    • Cyclic trends.
• Certain diseases appear in cycles, which may spread over short periods like days, weeks, months, or years
• Example: Automobile accidents
• Long term fluctuation
• Implies changes in disease occurrence over a long period, generally several years.
  Example: Lung cancer

2. Place Distribution:

• Variation in the frequency of different diseases from place to place has long been identified
• International variation
  • There exist differences in the incidence of various diseases in different parts of the world
  • Example: Stomach cancer is very common in Japan and unusual in the USA
  • National variation
    • Distribution of endemic goiter, fluorosis, leprosy, and malaria have shown variation in their distribution in India
• Urban and rural variation
  • Chronic bronchitis, lung cancer, and CVS disorder are more common in urban than rural areas Local distribution
• Inner and outer city variations in disease frequency are well-known

3. Person Distribution:

• The factors that influence the disease pattern in an individual are
• Age: certain diseases are more frequent in certain age groups
• Sex: obesity is common in females while lung cancer in males
• Ethnicity
• Marital status
• Occupation
• Social class
• Behavior
• Stress
• Migration

Measurement Of Disease:

• The measurement of disease is done in terms of mortality and morbidity indicators
• The morbidity is expressed in terms of incidence and prevalence

Comparing With Known Indices:

• It helps to conclude about the disease etiology
• Identify groups and subgroups which are potentially at high risk for the development of certain diseases

Formulation Of An Etiological Hypothesis:

• Formulation Of An Etiological Hypothesis is defined as ” a supposition arrived at by observation or by reflection”
• The formulation Of An Etiological Hypothesis can be tested using the techniques of analytical epi- epidemiology after which it may be accepted or rejected
• Formulation Of An Etiological Hypothesis should specify the population, specific cause, ex-expected outcome, dose-response relationship, and time response relationship

Cohort Study Vs Case-Control Study

Question 5. What are the aims of epidemiology? Explain. It is defined as the process by which we select control case-control studies in detail.
Answer:

Aims Of Epidemiology:

• To describe the size and distribution of the disease problems in the human population
• To provide the data essential for the planning, implementation, and evaluation of health services for the pre-prevention, control, and treatment of diseases and for setting up priorities among those services
• To identify etiological factors in the pathogenesis of disease

Epidemiology Features:

• Both exposure and outcome occurred before the start of the disease
• The study proceeds from effect to cause
• Epidemiology uses a control or comparison group to support to refuse a hypothesis

Epidemiology  Steps:

Epidemiology  Selection Of Cases And Controls:

• Selection of cases
• Definition of a case
  • Diagnostic criteria: the diagnostic criteria of the disease Epidemiology and the stage of the disease to be included in the study must be specified before the study is under- taken
  • Eligibility criteria: only newly diagnosed cases within a specified period are eligible than old cases or cases in advanced stages of disease
• Sources of cases
  • Hospitals
  • General population
• Selection of controls
• The control must be free from disease under study
• They must be as similar to the case as possible
• Sources of control
  • Hospital
  • Relatives
  • Neighborhood
  • General population
• Number of control
  • If many cases are available and a large study is contemplated, one tends to use one control for each
  • case
  • If the study group is small, 2,3 or even 4 controls can be selected for each study subject

Epidemiology Matching:

• In such a way that they are similar to cases about certain pertinent selection variables which is known to influence the outcome of the disease and which if not adequately matched for comparability could distort or confound the results
• While matching it should be borne in mind that the suspected etiological factor or the variable we wish to measure should not be a match

Epidemiology Types:

• Group matching
• Pair matching

Epidemiology Measurement Of Exposure:

• Obtained by
• Interviews
• Questionnaires
• Records
• Clinical or laboratory examination

Epidemiology Analysis:

• Final step
• It is to find out
• Exposure rates among cases and controls to suspected factor
• Estimation of disease risk associated with exposure

Epidemiology Advantages:

• Easy to carry out
• Rapid and Inexpensive
• Few subjects are required
• Rare diseases can be studied
• No risk to subjects
• Allows study of several etiological factors
• Risk factors can be identified
• No attrition problems
• Minimal ethical problems

Epidemiology Disadvantages:

• Problem of bias
• Selection of appropriate control group
• Incidence cannot be measured
• Not distinguishing between causes and associated factors
• Not suited to the evaluation of therapy
• The concern is the representativeness of cases and controls

Epidemiological Study Designs

Epidemiological Methods Short Essays

Question 1. Uses of epidemiology.
Answer:

Epidemiology Community Diagnosis:

• This consists of the collection, description, and analysis of information on the occurrence and distribution of disease in the population about characteristics of the agent, host, and environment
• The importance of the disease is usually determined by the extent of the incidence, prevalence, and mortality by age, sex, race, nativity, marital status, geographic area, temporal variation, and socio-economic status

Epidemiology Rise And Fall Of The Disease:

• The rise and fall of the disease is done through repeated evaluation of the health. It occurs when other factors that are associated with care-related matters
• Due to this, some diseases pale out in history while new ones emerge
• The seasonal nature of the disease may be revealed

Epidemiology Planning And Evaluation:

• Planning is essential for a rational allocation of the differences in admission rates and resources
• Evaluation is done to find out whether the measures undertaken to prevent a disease are effective in reducing the frequency of the disease

Evaluation Of Individual Risk:

• The purpose of this is to estimate the probable chances that certain types of individuals will, under certain conditions, suffer from specific illnesses, defects, or accidents
• Individual risk is also an estimate of the probabilities of life and death expectancy

Question 2. Bias in case-control studies.
Answer:

Selection Bias:

• Selection Bias occurs when a group studied does not reflect the same characteristics like age, sex, occupation, race, etc as in the general population
• Selection Bias can be reduced by careful selection of individuals for inclusion in the study
• The selection bias can be best controlled by the prevention

Information Bias:

• Information Bias occurs when there is an error in the classification of individuals concerning the outcome variable

Confounding Bias:

• The outcome and exposure variables do not have the same distribution in the exposed and unexposed groups
• Confounding Bias can be removed by matching

Berkesonian Bias:

• Of people in hospitals with different diseases

Interviewer’s Bias:

• Interviewer’s Bias occurs when the interviewer knows the hypothesis and also knows who the cases are

Memory Bias:

• When the cases and controls are asked questions about their history it may be more likely for the cases to recall the existence of certain events or factors than the controls who are healthy persons

Telescopic Bias:

• If a question refers to the recent past, episodes that occurred longer ago may also be reported

Prevalence-Incidence Bias:

• If the exposure occurred years before, then mild cases that improved or severe cases that died would have been missed and not counted among the cases

Question 3. Comparison of case-control and cohort studies.
Answer:

Comparison Of Case-control And Cohort Studies

Question 4. Incidence and prevalence.
Answer:

Incidence:

• Incidence is defined as the number of new cases of a specific disease occurring in a defined population during a specified period
• Incidence can range from zero to infinity
• Incidence can be represented by the formula
• Number of new cases of specific disease during a given period x 1000

The Population At Risk:

Incidence Types:

• Episode incidence
  • Episode incidence is the rate of occurrence of new episodes of a disease Identify the potential high-risk population
• Cumulative incidence
  • Similar to incidence the time interval is expressed as a fixed period.

Incidence Uses:

• Provide a clue for the etiology and pathogenesis of the disease
• Study the distribution of the study
• Control the disease
• Evaluate the efficacy of preventive and therapeutic measures.

Incidence Significance:

• Indicative of failure or preventive program
• Suggest the need for a new disease control program
• Suggest a change in the etiology of the disease

Prevalence:

• The total number of all individuals who have an attribute or disease at a particular time divided by the population at risk of having the attribute or disease at this point or midway through the period

Prevalence Types:

• Point prevalence
  • It is the number of all current cases of a specific disease at one point in time with a defined population
• Period prevalence
  • It is defined as the total number of existing cases of a specific disease during a defined period ex- pressed concerning a defined population

Prevalence Uses:

• Estimate the magnitude of disease or health problems in the community
• the disease under investigation
• Useful in administrative and planning purposes like assessing manpower needs in health services, etc

Relation Between Incidence and Prevalence:

• Prevalence is dependent on the incidence and duration of the disease
• Prevalence = incidence x Mean duration
• (P=IxD)
• Relation Between Incidence and Prevalence reveals that as the duration of the disease increases, the greater will be its prevalence
• Changes in prevalence from one time to another can result from changes in incidence, changes in duration of disease or both

Experimental Studies In Epidemiology

Question 5. Cohort studies.
Answer:

Cohort Studies

• Prospective study
• Longitudinal study
• Incidence study
• Forward-looking study

Cohort Studies Features:

• The cohorts are identified before the appearance of
• The study groups are observed over some time to determine the frequency of the disease among them
• The disease proceeds forward from cause to effect

Cohort Studies Indications:

• When a good association occurs between exposure and disease
• When exposure is rare
• When attrition of the study population can be minimized
• When ample funds are available

Cohort Studies Types:

• Prospective
• Retrospective
• Combination

Cohort Studies Elements:

• Selection of study subjects
  • Obtaining data on exposure
  • Selection of comparison group in terms of
    • Internal comparison
    • External comparison
• Comparison with general population rates
  • Follow up
  • Analysis

Question 6. Blinding.
Answer:

Blinding

• In order to reduce the problem of bias a technique called blinding is adopted
• It can be done in three ways
• Single-blind trial
• The trial is so planned that the participant is unaware of whether he belongs to the study group or the control group
• Double-blind trial
• The trial is so planned that neither the investigator nor the participant is aware of the group allocation and the treatment received
• The most frequently used method
• Triple blind trial
• The participant, the investigator, and the person analyzing the data are all blind
• Ideally used method

Question 7. Case-control studies
Answer:

Case-Control Studies

Case-Control Studies Features:

• Both exposure and outcome occurred before the start of the disease
• The study proceeds from effect to cause
• It uses a control or comparison group to support to re-fuse a hypothesis

Selection Of Cases And Controls:

• Selection of cases
• Definition of a case
  • Diagnostic criteria: the diagnostic criteria of the disease and the stage of the disease to be included in the study must be specified before the study is under- taken
  • Eligibility criteria: only newly diagnosed cases within a specified period of time are eligible than old cases or cases in advanced stages of disease
• Sources of cases
  • Hospitals
  • General population
• Selection of controls
  • The control must be free from disease under study
  • They must be as similar to the case as possible
• Sources of control
  • Hospital
  • Relatives
  • Neighbourhood
  • General population
• Number of control
  • If many cases are available and a large study is contemplated, one tends to use one control for each case
  • If the study group is small, 2,3 or even 4 controls can be selected for each study subject

Case-Control Studies Matching:

• Case-control studies Matching is defined as the process by which we select controls in such a way that they are similar to cases with regard to certain pertinent selection variables which is known to influence the outcome of the disease and which if not adequately matched for comparability could distort or confound the results
• While matching it should be borne in mind that the suspected etiological factor or the variable we wish to measure should not be a match

Case-Control Studies Types:

• Group matching
• Pair matching

Case-Control Studies Measurement Of Exposure:

• Obtained
• Interviews
• Questionnaires
• Past records
• Clinical or laboratory examination

Case-Control Studies Analysis:

• Final step
• Case-control studies Analysis is to find out
• Exposure rates among cases and controls to suspected factor
• Estimation of disease risk associated with exposure

Case-Control Studies Advantages:

• Easy to carry out
• Rapid and Inexpensive
• Few subjects are required
• Rare diseases can be studied
• No risk to subjects
• Allows study of several etiological factors
• Risk factors can be identified
• No attrition problems
• Minimal ethical problems

Case-Control Studies Disadvantages:

• Problem of bias
• Selection of appropriate control group
• Incidence cannot be measured
• Not distinguishing between causes and associated factors
• Not suited to the evaluation of therapy
• The concern is the representativeness of cases and controls

Types Of Epidemiological Studies

Question 8. Descriptive epidemiology.
Answer:

Descriptive Epidemiology Steps:

Defining The Population To Be Studied:

• The population has to be defined in terms of the total number and the composition of the individuals within the population in terms of characteristics such as age, sex, occupation, culture, socio-economic status
• The defined population can either be the total population in a geographic area or a representative sample taken from the population
• The defined population provides a denominator for calculating rates
• The population of the community selected for the study should always remain stable, without migration into or out of the area

Defining The Disease Under Study:

• The Disease should be precise and valid to enable the investigator to identify those who have the disease from those who do not
• The disease needs to be defined with an operational definition which is a definition with which the disease or condition can be identified and measured in the fined population with a degree of accuracy
• The diagnostic methods adopted for the study should be acceptable and applicable to the population to be studied

Describing The Disease Under Study

• This step is used to describe the occurrence and distribution of the disease by the time of its occurrence, the place of occurrence, and the persons who are affected by the disease

Time Distribution:

• Time may be measured in terms of hours, days, weeks, months, years, etc.
• Types
  • Short-term fluctuation ex. Epidemic
    • Common source epidemic
    • A single exposure or point source epidemic. Example: Food poisoning
  • Continuous or multiple exposure. Example: Contaminated water
• Propagated epidemic
  • Person-to-person transmission
  • Arthropod vector
• Animal reservoir
  • Periodic fluctuation
  • Seasonal trends: ex. Measles and varicella
  • Cyclic trends.
  • Certain diseases appear in cycles, which may spread over short periods of time like days, weeks, months, or years Example: Automobile accidents
• Long term fluctuation
  • Implies changes in the occurrence of disease over a long period of time, generally several years.
  • Example: Lung cancer

Place Distribution:

• Variation in the frequency of different diseases from place to place has long been identified
  • There exist differences in the incidence of various diseases in different parts of the world
  • Example: Stomach cancer is very common in Japan and usual in the USA
• National variation
  • Distribution of endemic goiter, fluorosis, leprosy, and malaria have shown variation in their distribution in India
• Urban and rural variation
  • Chronic bronchitis, lung cancer, and CVS disorder are more common in urban than rural areas
• Local distribution
  • Inner and outer city variations in disease frequency are well-known

Person Distribution:

• The factors that influence the disease pattern in an individual are
  • Age:
  • certain diseases are more frequent in certain age groups
  • Sex: obesity is common in females while lung cancer in males
  • Ethnicity
  • Marital status
  • Occupation
  • Social class
  • Behavior
  • Stress
  • Migration

Measurement Of Disease:

• The measurement of disease is done in terms of mortality and morbidity indicators
• The morbidity is expressed in terms of incidence and prevalence

Comparing With Known Indices:

• Comparing With Known Indices helps to conclude the disease. The total number of all individuals who have an attrib- etiology
• Identify groups and subgroups which are potentially at high risk for the development of certain diseases

Formulation Of An Etiological Hypothesis:

• Formulation Of An Etiological Hypothesis is defined as “a supposition arrived at by observation or by reflection”
• The formulation Of An Etiological Hypothesis can be tested using the techniques of analytical epi- epidemiology after which it may be accepted or rejected
• V should specify the population, specific cause, and example. pected outcome, dose-response relationship and
• time response relationship

Principles Of Epidemiological Methods

Question 9. Case-control studies
Answer:

Case-Control Studies

• In it, the same individuals are examined on repeated occasions over a prolonged period using follow-up examination

Case-Control Studies Uses:

• Study the natural history of the disease & its outcome
• Identify the risk factor associated with the disease
• Calculate the incidence rates of the disease

Case-Control Studies Disadvantage:

• Difficult to organize
• More time consuming

Epidemiological Methods Short Question And Answers

Question 1. Attributable risk (AR).
Answer:

Attributable risk (AR)

• Attributable risk is often expressed as a percent
• Attributable risk indicates to what extent the disease under study can be attributed to the exposure
• AR= Incidence of disease rate among exposed Inci- dence of disease rate among non-exposed/Incidence rate among exposed

Question 2. Cohort Studies.
Answer:

Cohort Studies Features:

• The cohorts are identified prior to the appearance of the disease under investigation
• The study groups are observed over a period of time to determine the frequency of the disease among them
• The disease proceeds forward from cause to effect

Cohort Studies Indications:

• When a good association occurs between exposure & disease
• When exposure is rare
• When attrition of the study population can be minimized
• When ample funds are available

Cohort Studies Types:

• Prospective
  • Retrospective
  • Combination

Question 3. Cohort.
Answer:

Cohort

• Thus a group of people born on the same day or in the same period of time form a “birth cohort”
• which the cohort is derived or it may be another cohort. It can be represented by the formula little or no exposure to the substance in question

Question 4. Single-blind trial.
Answer:

Single-Blind Trial

• In order to reduce the problem of bias a technique called blinding is adopted
• Single-blind trial
• The trial is so planned that the participant is unaware of whether he belongs to the study group or the control group

Question 5. Long-term/secular trends.
Answer:

Long-Term/Secular Trends

• It refers to changes in disease frequency that occur gradually over a long period of time generally several years or decades
• Examples: Coronary heart disease, lung cancer & diabetes
• Oral cancer has shown a consistent upward trend during the last 50 years in developed countries

Question. 6. Prevalence.
Answer:

Prevalence

The total number of all individuals who have an attribute or disease at a particular time divided by the population at risk of having the attribute or disease at this point in time or midway through the period

Prevalence Types:

• Point prevalence
  • It is the number of all current cases of a specific disease at one point in time in relation to a defined population
• Period prevalence
  • It is defined as the total number of existing cases of a specific disease during a defined period of time expressed in relation to a defined population

Prevalence Uses:

• Estimate the magnitude of disease or health problems in the community
• Identify the potential high-risk population
• Useful in administrative & planning purposes like assessing manpower needs in health services, etc

Question 7. Parkinsonian Bias.
Answer:

Parkinsonian Bias

• Parkinsonian Bias is named after Dr. Joseph Berkson
• Parkinsonian Bias arises when there are differences in admission rates of people in hospitals with different diseases
• The causes of bias include the burden of symptoms, ac- TELESCOPIC BIAS: cess to care & popularity of certain institutions
• It is more common in observational studies, particularly in case-control studies

Question 8. Bias.
Answer:

Selection Bias:

• Selection Bias occurs when a group studied does not reflect the same characteristics like age, sex, occupation, race, etc as in the general population

Interviewer’s Bias:

• Interviewer’s Bias occurs when there is an error in the classification of individuals with respect to the outcome variable

Confounding Bias:

• Confounding Bias occurs when other factors that are associated with the outcome & exposure variables do not have the same distribution in the exposed & unexposed groups
• Confounding Bias can be removed by matching

Berkesonian Bias:

• Berkesonian Bias arises when there are differences in admission rates of people in hospitals with different diseases

Information Bias:

• Information Bias occurs when the interviewer knows the hypothesis & also knows who the cases are

Memory Bias:

• When the cases & controls are asked questions about their history it may be more likely for the cases to recall the existence of certain events or factors than the controls who are healthy persons

Telescopic Bias:

• If a question refers to the recent past, episodes that occurred longer ago may also be reported

Prevalence-Incidence Bias:

• If the exposure occurred years before, then mild cases that improved or severe cases that died would have been missed & not counted among the cases

Uses Of Epidemiological Methods

Question 9. Double-blind trial.
Answer:

Double-Blind Trial

• In order to reduce the problem of bias a technique called blinding is adopted
• Triple blind trial
• The participant, the investigator & the person analyzing the data are all blind
• Ideally used method

Question 10. Randomized trial.
Answer:

Randomized Trial Steps:

• Drawing up a protocol
• Selecting reference & experimental population
• Randomization
• Manipulation or intervention
• Follow up
• Assessment of outcome

Randomized Trial Types:

• Clinical trials
  • Prophylactic trials
  • Therapeutic trial
  • Safety trial
  • Risk-factor trial
• Preventive trial
• Risk factor trials
• Cessation experiments
• Trial of etiological agents
• Evaluation of health services
• Community intervention trial

Question 11. Confounding factor.
Answer:

Confounding Factor

• A confounding factor is defined as one that is associated both with the exposure & disease & is unequally distributed in study & control groups
• A confounding factor is one that although associated with exposure under investigation is itself independent of any such association, a risk factor for the disease
• Example: role of alcohol in the etiology of esophageal cancer
• Smoking is a confounding factor because
• A confounding factor is associated with the consumption of alcohol
• A confounding factor is an independent risk factor for esophageal cancer

Epidemiological Methods Viva Voce

1. Prevalence incidence mean duration
2. The epidemic is the best example of short-term fluctuations
3. Cohort studies are also called longitudinal studies
4. A confounding factor is associated with both exposure and disease
5. Carriers of avirulent organisms are called pseudo-carriers
6. The science of the health of travelers is called emporia tics
7. John Snow is the father of epidemiology
8. Case-control study begins with the identification of jects with a specific disease and studies for risk factors
9. Case-control studies proceed backward from effect to cause. So it is also known as a retrospective study
10. In a cohort study, a group of the population who has been exposed to a risk factor is identified and followed over an extended period
11. A cohort study proceeds from cause to effect so it is known as a prospective study.
12. Panel study is another name for cohort study. Total number of cases of disease at a given time Estimated total population
13. Prevalence =\(\frac{\begin{array}{c}\text { Total number of cases } \\\text { of disease at given time }\end{array}}{\begin{array}{c}\text { Estimated total population } \\\text { at same time }\end{array}} \times 100\)
14. Incidence =\(\frac{\begin{array}{c}\text { Number of new cases of } \\\text { specific disease at given time }\end{array}}{\text { Population at risk }} \times 100\)
15. Cross-sectional study measures the disease to assess the association between risk factors and disease
16. The case-control study measures the prevalence of the disease
17. In cross-sectional studies, different individuals of a particular group are studied only once
18. In longitudinal studies, the same individual is studied at different ages
19. Berkonsian bias occurs due to different rates of admission to hospitals for people with different diseases
20. Confounding bias is reduced by matching
21. Selection bias is controlled by the prevention
22. The interviewer’s bias is eliminated by double-blinding
23. Cross-sectional studies are useful for chronic diseases
24. Hippocrates is the Father of medicine
25. Alfred Fones is the Father of dental hygiene.

Health Education Definitions

Health Education

• Health education is a process that informs, motivates & helps people to adopt & maintain healthy practices and lifestyles, advocates environmental changes as needed to facilitate this goal & conducts professional training & research to the same end

Community Dentistry

• Community Dentistry is concerned with dental disease prevention & dental health care services to all the people of the community, the rich, the poor, the educated, the disadvantaged, middle class, urban & rural persons of every racial, religious & ethnic group

Propaganda

• Propaganda is a publicity campaign aimed at presenting a particular thing/ concept in a favorable light in such a way that the public may accept it without thinking about it analytically

Read And Learn More:  Percentive Communitive Dentistry Question And Answers

Health Education Important Notes

1. Principles of health education

• Credibility:
• Interest
• Participation
• Motivation
• Comprehension:
• Reinforcement
• Learning by doing:
• Known to unknown
• Setting an example
• Good human relation
• Feedback
• Leaders

2. Soil, seed, sower

Soil, seed, and sower form the important components of any health education program All components are interdependent and result in dynamic interaction

3. Approaches to health education

1. Individual approach
   • Personal contact
   • Personal letters
   • Home visits
2. Group approach
   • Lecture
   • Demonstration
   • Discussion methods
   • Group discussion
   • Panel discussion
   • Workshop
   • Symposium
   • Seminars and conferences
   • Role-playing
3. Mass media
   • TV
   • Radio
   • Newspapers
   • Printed material
   • Direct mailing
   • Posters, billboards, signs
   • Health museums and exhibitions
   • Folk media
   • Internet
   • Mobile

Community Dentistry Questions And Answers

Health Education Long Essays

Question 1. Define Health education. Write about principles. of health education, discuss the role of mass media in educating people at large (or) Define health education. Write in detail about the principles of health education (or) Define health education. Give your plan for educating the population of Andhra Pradesh on the prevention of dental diseases.
Answer:

Health Education Definition:

• Health education is a process that informs, motivates, and helps people to adopt & maintain healthy practices and lifestyles, advocates environmental changes as needed to facilitate this goal, and conducts professional training & research to the same end

Health Education Interest:

• The health educator should identify the felt needs of the people
• Health education should relate to the interests of the people

Health Education Participation:

• The health educator should encourage people to participate in the program
• Group discussions, panel discussions, and workshops all provide opportunities for active learning

Health Education Motivation:

Health Education Definition: the fundamental desire for learning in an individual

Health Education Types: primary and secondary

• Primary motive: inborn desires. Ex. Food, clothing, housing
• Secondary motives: desires resulting from outside forces. Ex. Gifts, love, word of praise, reward
• Health education can be facilitated by the motivation provided by the desire to achieve individual goals

Health Education Comprehension:

• The health educator must know the level of understanding, education & literacy of people
• Words that are strange/ new to the people should not
• Teaching should be within the mental capacity of the audience

Health Education Reinforcement:

• Repetition of new concepts done at regular intervals helps people to understand it

Health Education Learning by Doing:

• If the learning process is accompanied by doing new things, it is better instilled in the minds of the people
• Health Education Learning by Doing is based on the famous Chinese proverb, “If I hear, I forget, if I see, I remember, if I do, I know”

Health Education Known to Unknown:

• Health education should start where the people are & with what they understand & then proceed to new knowledge

Health Education Setting an Example:

• The health educator should set an example for other people to follow

Health Education Good Human Relations:

• The health educator must be kind, sympathetic & should have good personal qualities

Health Education Feedback:

• Health Education is necessary to find out if any modifications are needed

Health Education Leaders:

• If the leaders are convinced first about the program, then implementing the program will be easy as they are respected by the people of the community

Health Education Soil. Seed And Sower:

• The people are the soil
• Seeds: health facts- must be truthful
• Sower: transmitting media- should be attractive, pal- a table & acceptable

Health Education In Community Dentistry 

Health Education Role of Mass Media:

Useful in transmitting messages to people even in remote areas

• The Health Education Role of Mass Media can reach a large number of people
• People of all socio-economic statuses irrespective of their caste, creed, and religion have access to health education
• The effectiveness can give high returns for the time and money involved.

Question 2. Define community dentistry. What are the dif- be used different methods for mass communication? (or) Public health approach/mass approach
Answer:

Community Dentistry Definition:

• Community Dentistry is concerned with dental disease prevention & dental health care services to all the people of the community, the rich, the poor, the educated, the disadvantaged, middle class, urban & rural persons of every racial, religious, and ethnic group

1. Mass Approach:

• The most common and effective approach

Community Dentistry Advantage:

• Reaches a large number of people
• Useful for people irrespective of their socio-economic status, caste, creed, or religion.

Community Dentistry Disadvantage:

• One-way communication
• Media

Community Dentistry Mass Communication:

Question 3. Define Health education. What are the different approaches in health education? Discuss the most common & effective approach used.
Answer:

Health Education Definition:

• Health education is a process that informs, motivates, and helps people to adopt and maintain healthy practices and lifestyles, advocates environmental changes as needed to facilitate this goal, and conducts professional training and research to the same end

Health Education Individual Approach:

• Individual Approach is used by public health personnel like public health Advantage: nurses, health visitors & health inspectors
• They interact with the individual and their families

Health Education Advantage:

• This can be done in the dentist’s consultation room
• Can discuss, argue & persuade the individual to change the Disadvantages of his behavior
• Provide the opportunity for the individual to ask questions & clear doubts

Role Of Health Education In Community Dentistry

Health Education Disadvantage:

• The number we reach is small

Health Education Group Approach

• An effective way of educating the community
• Methods

Health Education Mass Approach

• The most common and effective approach

Health Education Advantage

• Reaches a large number of people
• Useful for people irrespective of their socio-economic status, caste, creed, or religion.

Health Education Disadvantage

• One-way communication

Health Education Media:

• Refer to the previous question

Health Education Short Essays

Question 1. Differentiating between health education and Health education should relate to the interest of the propaganda.
Answer:

Difference Between Health Education And Propaganda

Question 2. Visual aids to health education.
Answer:

Visual aids to health education help individuals understand better

Visual Aids To Health Education Classification:

Question 3. Barriers to communication/ health education.
Answer:

Barriers To Communication Psychological:

• Emotional disturbances, depression, or neurosis
• When interacting with individuals with these problems, special methods & utmost care should be adopted

Barriers To Communication Physiological:

• Include difficulties in self-expression, difficulties in hearing/seeing, difficulties in understanding
• While educating them specific media of communication should be selected

Barriers To Communication Environmental:

• Including excessive noise, difficulties in vision & congestion
• Overcome by making small groups

Barriers To Communication Cultural:

• Barriers To Communication depends on levels of knowledge and understanding, customs, beliefs, attitudes

Community Oral Health Education 

Question 4. Models of health education.
Answer:

Medical Model:

• The medical Model is concerned with the identification and treatment of diseases and technological advances to facilitate this process
• This medical information is provided to people
• But as it doesn’t give importance to the social, cultural, and psychological factors it couldn’t succeed

Motivation Model:

• To make the health information effective, the individual is motivated to put it into action

Social Intervention Model:

• This model describes the importance of social environment besides focusing on an individual’s health

Question 5. Contents of health education.
Answer:

Human Biology:

• Children are taught about
• Parts of the human body and their functions
• Importance of good health
• Need for exercise, adequate rest, and sleep
• Adverse habits like smoking, alcohol
• Methods of First Aid

Nutrition:

• People should be taught about
• Nutritive value of foodstuffs
• Effect of nutrition on health
• Optimum and balanced diet

Hygiene:

• People are taught about
• The importance of hygiene and methods of maintaining it

Aspects:

• Personal hygiene
• Environmental hygiene
  • Domestic hygiene
  • Community hygiene

Family Health Care:

• Family Health Care is to strengthen and improve family health especially maternal oral health to improve the oral health of the child

Control Of Communicable and Non-Communicable Diseases:

• Family Health Care is to provide knowledge about common signs and symptoms- Q. 1. Chalk and talk method. toms of disease and their prevention

Prevention Of Accidents:

• People are taught about basic safety rules and the use of mouth guards while doing sports to prevent oro-facial trauma

Question 6. Educational aids.
Answer:

Educational Aids

• Suitable for group
• Effective when used in a good environment with good light. Each speaker presents an aspect of the subject briefly, including ventilation, temperature, and comfortable seating

Auditory Aids:

• Based on the principles of sound, electricity & magnetism

Aids:

• Megaphones, gramophones, tape recorders, radio, sound amplifier
• Advantage
• Can reproduce any kind of spoken words
• Used for entertainment & mass communication

Importance Of Health Education In Dentistry

Visual Aids:

• It helps individuals understand better
• Classification

Combination Of Audio-Visual Aids:

• Audio-Visual Aids creates a better presentation as it combines both sound & sight
• Combination Of Audio-Visual Aids includes
  • Television
  • Tape and slide combination
  • Video cassette players and recorder
  • Motion pictures or cinemas

Health Education Short Question And Answers

Question 1. Chalk and talk methods
Answer:

Chalk and talk methods

• Chalk and talk is a method of group health education method
• Consists of an opening statement giving the theme of the lecture
• In it, the group should not exceed more than 30 people
• Duration should not exceed 15-20 minutes
• Chalk and talk should be based on the topic of people’s interest

Question 2. Symposium.
Answer:

Symposium

• Symposium comprises a series of speeches on a selected topic
• Each speaker presents an aspect of the subject briefly
• No discussion occurs among speakers
• In the end, the audience may ask questions & at last, the chairman makes a summary of the topic

Question 3. Motivation.
Answer:

Motivation

• Definition: the fundamental desire for learning in an individual
• Types: primary and secondary
• Primary motive: inborn desires. Ex. Food, clothing, housing
• Secondary motives: desires resulting from outside forces. Ex. Gifts, love, word of praise, reward
• Health education can be facilitated by the motivation provided by the desire to achieve individual goals

Dental Public Health Questions 

Question 4. Audio-visual aids.
Answer:

Audio-Visual Aids

• Audio-visual aids create a better presentation as it combine both sound and sight
• Audio-visual aids include
  • Television
  • Tape and slide combination
  • Video cassette players and recorder
  • Motion pictures or cinemas

Health Education Viva Voce

1. A series of charts displayed one after the other before a group is a flip chart.
2. A series of speeches on a selected subject is a symposium.
3. A carefully prepared presentation to show how to perform a skill or procedure is called a demonstration
4. Mass media is an example of one-way communication
5. Health education failing as a result of illiteracy is due to cultural barrier
6. Health education differs from propaganda in developing reflective behavior
7. The Chinese proverb ” If I hear, I forget, if I see I remember, if I do I know” illustrates learning by doing the principle of health education.
8. Education can be given only to people who come in contact with an individual approach is it limitation.

Nutrition In Health And Disease Definitions

Balanced diet

• A balanced diet contains a variety of foods in such quantities and proportions that the need for energy, amino acids, vitamins, minerals, fats, carbohydrates and other nutrients is adequately met for maintaining health, vitality and general well-being and also makes a small provision for extra nutrients to withstand the short duration of leanness

Nutrition:

• Nutrition is defined as the sum of the processes by which an individual takes in and utilizes food

Diet:

• Diet is defined as the types and amounts of food eaten daily by an individual

Malnutrition:

• Malnutrition is the pathological state resulting from a relative/ absolute deficiency or excess of one/ more essential nutrients.

Nutrition In Health & Disease Important Notes

1. Fat-soluble vitamins

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2. Water-soluble vitamins

Nutrition In Health And Disease Short Essays

Question 1. Trace elements.
Answer:

Trace elements

• WHO has recognized 14 trace elements
• They are
• Iron
• Zinc
• Copper
• Manganese
• Silicon
• Molybdenum
• Iodine
• Cobalt
• Tin
• Fluorine
• Chromium
• Nickel
• Selenium
• Vanadium

Nutrition In Health And Disease Mcqs

Question 2. Fat-soluble vitamins.
Answer:

Fat-soluble vitamins

Nutrition In Health And Disease Short Question And Answers

Question 1. Molybdenum and dental caries.
Answer:

Molybdenum & dental caries

• Molybdenum is cariostatic
• Thus it reduces the acid solubility of calcified dental tissues

Question 2. Vitamin K.
Answer:

Vitamin K

Question 3. Balanced diet.
Answer:

Balanced diet

• A balanced diet contains a variety of foods in such quantities and proportions that the need for energy, amino acids, vitamins, minerals, fats, carbohydrates & other nutrients is adequately met for maintaining health, vitality and general well-being & also makes a small provision for extra nutrients to withstand the short duration of leanness
• It contains

Nutrition And Disease Questions And Answers

Question 4. Vitamin D.
Answer:

Vitamin D

Question 5. Vitamin B complex.
Answer:

Vitamin B complex

Question 6. Enumerate nutritional problems in public health.
Answer:

Nutritional problems in public health

• Low birth weight
• Protein-energy malnutrition
• Xerophthalmia
• Nutritional anemia
• Iodine deficiency disorder
• Endemic fluorosis
• Lathyrism

Role Of Nutrition In Health Mcqs

Question 7. Define Diet, Nutrition, and Malnutrition.
Answer:

Diet:

• Diet is defined as the types and amounts of food eaten daily by an individual

Nutrition:

• Nutrition is defined as the sum of the processes by which an individual takes in and utilizes food

Malnutrition:

• Malnutrition is a pathological state resulting from a relative/absolute deficiency or excess of one/ more essential nutrients.

Nutrition In Health And Disease Viva Voce

1. 14 trace elements are recognized
2. Vitamins A, D, E, and K are fat-soluble vitamins
3. Vitamins B and C are water-soluble vitamins
4. Vitamins and minerals are referred to as micronutrients
5. Vitamin A deficiency is the single most frequent cause of blindness among preschool children in developing countries
6. Milk and egg proteins have all essential amino acids so are considered biologically complete food.

Environment And Health Definitions

Garbage

Garbage means discarded vegetable matter from kitchens, canteens, etc.

Sullage – Refers to fluid waste from a kitchen unmixed with excrement

Water sewage – Refers to wastewater from households, industries, etc containing human excreta

Refuse – Refuse is all solid and semi-solid waste matters of a community except excrement

Breakpoint chlorination

The point where the addition of chlorine to water results in the appearance of free residual chlorine is called break-point chlorination

Environment And Health Questions And Answers

Environment And Health Important Notes

1. Biological wastes

Categories Of Biomedical Wastes

Color Coding

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2. Methods of disposal of solid wastes

1. Dumping – Refuse is dumped in low-lying areas
2. Controlled tipping- Material is placed in a trench
3. Incineration- It is the best method for the disposal of healthcare
4. Composting- It is the process of nature where matter breaks down under bacterial action resulting in the formation of humus-like material called compost
5. Manure pits- Manure pits are dug by individual householders to dump the garbage
6. Burial – A trench is excavated and at the end of each day the trench is filled with earth and compacted

3. Composting is a method wherein sludge is combined with solid wastes to produce manure-quality material

• There are two commercial methods of composting

1. Bangalore method

• Bangalore method is a natural hot fermentation process in which trenches are dug and filled alternatively with refuse and excreta

2. Mechanical method

• The mechanical method involves pulverization of raw materials and mixing them with sludge.

4. Incineration

• Incineration is a high-temperature dry oxidation process that reduces organic and combustible waste to inorganic, incom- combustible matter resulting in a significant reduction of waste volume and weight
• Types
  • Double-chamber pyrolytic incinerators
  • Single chamber furnaces
  • Rotary kilns
• Incineration is the choice of disposal for the following wastes
  • Human anatomical waste
  • Animal waste
  • Microbiology and biotechnology waste
  • Discarded medicines and cytotoxic drugs
  • Contaminated solid wastes
• Wastes that should never be incinerated are
  • Amalgams
  • Latex gloves
  • Lead wastes
  • PVC plastics

Relationship Between Environment And Health

5. Loss of head

• As filtration proceeds, the suspended impurities and bacteria clog the filters and they soon become dirty and
• begin to lose their efficiency
• This is known as loss of head
• When the loss of the head approaches 7-8 feet, filtration is stopped and subjected to backwashing.

Environment And Health Long Essays

Question 1. Describe in detail the small-scale purification.
Answer:

Small-Scale Purification:

Environment And Health Short Essays

Question 1. Principles of chlorination.
Answer:

Principles Of Chlorination

• The water to be chlorinated should be clear & free from turbidity
• The chlorine demand of the water should be estimated
• The point at which the chlorine demand of the water is met is called the “breakpoint”
• If further chlorine is added, free chlorine begins to appear in the water
• The free residual chlorine should be present for a contest 1 hour to kill bacteria & viruses
• The minimum recommended concentration of free. It is defined as water that is chlorine is 0.5 mg/L for 1 hour
• The correct dose of chlorine to be applied = chlorine de- mand of water + free residual chlorine.

Question 2. Occupational hazards for dentists.
Answer:

Occupational Hazards For Dentists

Question 3. Potable water.
Answer:

Potable Water

• Potable water is defined as water that is
  • Free from pathogens
  • Free from harmful chemicals
  • Pleasant to taste
  • Usable for domestic needs
• Potable Water Requirements:
  • Must be close to the people as its transportation may lead to pollution
  • The basic requirement at about 2 L/head/day
  • A daily supply of 150-200 L/capita is considered adequate to meet the domestic needs of the urban population
• Potable Water Uses
  • Domestic purposes: drinking, cooking
  • Public purposes: cleaning streets & fire protection
  • Industrial purposes: factories
  • Agricultural purposes: irrigation

Impact Of Environment On Human Health

Question 4. Disposable of hospital waste.
Answer:

Hospital Waste Dumping:

• Waste/refuse is dumped in low-lying areas
• Hospital Waste Dumping is a suitable method for the reclamation of land
• As a result of bacterial action, refuse decreases consist of each day the erably in volume and is converted gradually into humus

Hospital Waste Controlled Tipping:

• Here, the material is placed in a trench or other pared area, adequately compacted and covered with earth at the end of the working day

Hospital Waste Trench Method:

• A long trench is dug out 6-10 feet deep & 12-36 feet wide into which refuse is compacted & covered with caveated earth
• Ramp method
• Moderately sloping terrain is used Area method
• The refuse is deposited & sealed on its exposed face with a mud cover
• Changes occurring in refuse raise the temperature to 60 degrees C within 7 days & kill all the pathogens

Hospital Waste Incineration:

• By it, the refuse is reduced to 1/4th its original weight & the residue is called “clinker” and used for road making
• The incinerator consists of:
• A furnace
• A platform: for tipping refuse
• Baffle plate: to drive out all fumes

Hospital Waste Types:

• Double cell Meldrum
• Single-cell destructor

Hospital Waste Composting:

• It is a process of nature where matter breaks down under bacterial action resulting in the formation of relatively stable humus-like material called compose
• The compost formed contains few or no disease-producing agents
• The heat produced destroys all pathogens

Hospital Waste Manure pits

• Dug by individual householders to dump garbage& other waste & covered with earth after each day’s dumping

Environmental Health Hazards

Question 5. Rapid sand filtration.
Answer:

Rapid Sand Filtration

Rapid Sand Filtration Types:

1. Gravity type
2. Pressure type

Rapid Sand Filtration Steps:

Coagulation:

• Raw water is first treated with chemical coagulants such as alum

Rapid Mixing:

• The water is then violently agitated in a “mixing chamber” for a few minutes

Flocculation:

• It involves slow and gentle stirring of treated water in a “flocculation chamber” for 30 minutes

Sedimentation:

• The water is then led into sedimentation tanks & kept for 2-6 hours

Filtration:

• The water is then subjected to filtration

Question 6. Composting.
Answer:

Composting Methods:

Bangalore/Anaerobic/ Hot Fermentation Process:

• Trenches are dug 3 feet deep, 5-8 feet broad, 15-30 feet long & located at least 800 m away from the city limits
• First, a layer of refuse is spread followed by nightsoil
• Similarly, alternate layers of refuse & nightsoil are added till the heap rises 1 foot above the ground level
• The top layer should be of refuse, at least 9 inches in thickness which is covered with excavated earth & compacted
• Within 7 days, considerable heat is generated which persists over 2-3 weeks
• Duration: 4-6 months
• Result
• The resulting material is a well-decomposed, odorless, nocuous material of high-manured value

Mechanical/ Aerobic Method:

• The refuse is first cleared of salvable material
• Then pulverized in pulverizing equipment
• The pulverized refuse is then mixed with sewage, sludge, or night soil in a rotating machine & incubated
• Duration: 4-6 weeks

Types Of Environmental Pollution

Question 7. Elements of a slow sand filter.
Answer:

Supernatant Water:

• Depth: 1-1.5 m above the sand bed
• Purposes
  • Provides constant head of water
  • Provides a waiting period of some hours for the raw water

A Bed of Graded Sand:

• Thickness: about 1 m
• The sand bed is supported by a layer of graded gravel
• Water percolates through the sandbed very slowly
• Then it is subjected to mechanical straining, sediments bacterial action

Under Drainage System:

• Consist of porous/ perforated pipes
• Purpose
• Provides an outlet for filtered water
• Support filter medium above

Filter Control:

• Filter Control maintains a constant rate of filtration
• The venturi meter is used to measure the loss of head/ bed resistance
• When the resistance builds up the operator opens the regulating valve to maintain a steady rate of filtration

Question 8. Incineration
Answer:

Incineration

• Incineration is a high-temperature dry oxidation process that duces organic and combustible waste to inorganic, combustible matter resulting in a significant reduction of waste volume and weight

Incineration Types

• Double-chamber pyrolytic incinerators
  • Single chamber furnaces
  • Rotary kilns
• Incineration is the choice of disposal for the following wastes
  • Human anatomical waste
  • Animal waste
  • Microbiology and biotechnology waste
  • Discarded medicines and cytotoxic drugs
  • Contaminated solid wastes
• Wastes that should never be incinerated are
  • Amalgams
  • Latex gloves
  • Lead wastes
  • PVC plastics

Environment And Health Short Question And Answers

Question 1. Compositing.
Answer:

Compositing

• Compositing is a process of nature where matter breaks down un- der bacterial action resulting in the formation of relatively stable humus-like material called compose
• The compost formed contains few or no disease-producing agents
• The heat produced destroys all pathogens
• By-products: carbon dioxide, water, heat

Methods: Bangalore method, mechanical composting

Air Pollution And Health Effects

Question 2. Backwashing.
Answer:

Backwashing

• Rapid sand filters need frequent washing daily/weekly depending upon the loss of head
• Washing is accomplished by reversing the flow of water through the sand bed-back washing
• Washing is stopped when the wash water is sufficiently clean
• Compressed air is used

Backwashing Effects:

• Dislodges the impurities
• Cleans the sand bed

Duration of Process: 15 minutes

Question 3. Loss of head.
Answer:

Loss Of Head

• When the filtration proceeds the suspended impurities & bacteria clog the filter
• This results in their reduced efficiency called “loss of head”

Loss Of Head Effects:

• Filters soon become dirty
• When “loss of head” approaches 7-8 feet, filtration is stopped
• Filters are subjected to backwashing

Question 4. Vital layer.
Answer:

Vital Layer Definition:

• The vital layer is the slimy growth covering the surface of the sand bed

Vital Layer Synonym:

• Schmutzdecke, zoogleal layer, biological layer

Vital Layer Components:

• Threadlike algae
  • Plankton
  • Diatoms
  • Bacteria

Vital Layer Formation:

• Vital layer formation of the vital layer is known as the “ripening” of Disadvantages: filter
• The vital layer takes several days the form

Vital Layer Significance:

• The vital layer is the heart of the slow sand filter
• Removes organic matter
• Holds back bacteria
• Oxidizes ammonical nitrogen into nitrates
• Purifies water

Question 5. Breakpoint chlorination.
Answer:

Breakpoint Chlorination

• The fall in residual chlorine continues with a further increase in chlorine dose, until after a stage residual chlorine begins to increase in the proportion
• The point where the addition of chlorine to water results in the appearance of free residual chlorine is called breakpoint chlorination
• When the chlorine dose in the water is increased a reduction in the residual chlorine occurs

Water Pollution And Diseases

Question 6. The hardness of the water.
Answer:

The Hardness Of The Water Definition:

• The hardness of the water is defined as the soap-destroying power of water

Hardness Of The Water Causes:

• Calcium bicarbonate
• Calcium sulfate
• Magnesium bicarbonate
• Magnesium sulfate

Classification Of Hardness Of The Water:

• Carbonate/temporary hardness
• Non-carbonate/ permanent hardness

Hardness Of The Water Expressed as: milliequivalent/L

The Hardness Of The Water Removed as:

• Temporary hardness
  • Boiling
  • Addition of lime
  • Addition of sodium carbonate
  • Permutit process
• Permanent hardness
  • Addition of sodium carbonate
  • Base exchange process

Hardness Of The Water Disadvantages:

• Consumes more soap And detergent
• Causes furring of boilers
• Effects cooking
• Fabrics washed do not have a long life
• Results in economic losses
• Shortens the life of pipes & fixtures

Question 7. Sources of water.
Answer:

Sources Of Water

• Rain-main source
• Surface water
  • Sources of water ultimately flow into the sea
  • Impounding reservoirs- artificial lakes/ constructed dams
  • Rivers and streams: grossly polluted and unfit for drinking
  • Ponds and lakes: natural excavation
  • Sea water: contains 35% of salts in solution
• Groundwater: formed by percolated rainwater
  • Shallow wells: above the 1st impervious layer in the ground
  • Deep wells: below the 1st impervious layer in the ground
  • Tube wells: shallow/ deep, costly to construct & operate
  • Springs: shallow/deep, easily contaminated

Question 8. Controlled tipping.
Answer:

Controlled Tipping

• Controlled Tipping
  • Here, the material is placed in a trench or other pared area, adequately compacted and covered with earth at the end of a working day
• Methods
• Trench Method
  • A long trench is dug out 6-10 feet deep and 12-36 feet wide into which refuse is compacted and covered with excavated earth
• Ramp method
  • Moderately sloping terrain is used
  • Area method
    • The refuse is deposited & sealed on its exposed surface with a mud cover
    • Changes occurring in refuse raise the temperature to 60 degrees C within 7 days and kill all the pathogens

Environmental Sanitation In Public Health

Question 9. Waterborne diseases.
Answer:

Waterborne Diseases

Question 10. Domestic refuse.
Answer:

Domestic Refuse

• Domestic refuse consists of ash, rubbish, and garbage
• Ash:
• Ash is the residue from the fire used for cooking and heating Rubbish:
• Comprises of wood bits, paper, clothing, metal, glass, dirt and dust
• Garbage:
• Garbage consists of waste food, vegetable peeling, and organic matter
• Garbage needs quick removal and disposal because it ferments on storage

Environment And Health Viva Voce

1. The slimy growth covering the surface of the sand bed
2. Rapid sand filter is an earlier method of filtration where 99.9% of impurities are filtered out.
3. Clinical wastes are disposed of in yellow bags and non-clinical wastes are disposed of in black bags
4. Incinerators are used to burn all the combustibles at a temperature of 1300-1500 degrees C
5. Bangalore’s method of composting is anaerobic.
6. Occupational hazards to dentists result from accidental infection
7. Residual chlorine of water should be 0.5 mg/ltr after 1 hour
8. The temporary hardness of water is due to the presence of salts of calcium and phosphorous bicarbonates
9. Dumping is considered as most unsanitary method of waste disposal.
10. Waste sharps from hospitals should be discarded in
11. The heat produced over 60 degrees C in composting kills
12. Composting is a combined method of disposal of re-fuse and nightsoil.
13. Dumping is the most commonly used method of waste disposal posing a health hazard in India.
14. The hardness of water is expressed in terms of oil- oil-equivalent per liter
15. The permanent hardness of water can be removed by base blue/white translucent bins. exchange process
16. Chlorination of water acts by killing pathogenic bacteria the pathogenic organisms.
17. Rainwater is the purest form of water

Practice Of Public Health Definitions

Public health:

Public health is the science and art of preventing disease, prolonging life, and promoting physical and mental efficiency through organized community efforts for the sanitation of the environment, the control of communicable infections, the education of the individual in personal hygiene, the organization of medical and nursing services for the early diagnosis and preventive treatment of diseases.

The development of the social machinery to ensure everyone a standard of living adequate for the maintenance of health, so organizing these benefits as to enable every citizen to realize his birthright of health and longevity- Winslow

Practice Of Public Health Important Notes

Procedural Steps in Dental Public Health Practice

• Survey
• Analysis
• Program planning
• Ethics
• Program operation

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• Financing
• Program appraisal

Practice Of Public Health Mcqs

Practice Of Public Health Short Essays

Question 1. History of Public Health Dentistry
Answer:

History of Public Health Dentistry

Question 2. Procedural steps in dental public health.
Answer:

Dental Public Health Survey:

• The Dental Public Health Survey focuses on the population rather than the individual
• Surveys are methods for collection of data, analyzing & evaluating them to determine the number of disease problems in a community and also to identify cases that have not been identified
• Dental Public Health Survey undergoes clinical assessments of the extent and severity of the disease

Dental Public Health  Analysis:

• Dental Public Health  Analysis is done to define the characteristics of specific health problems in the community
• Here, the science of statistics is applied to achieve a correct diagnosis.
• Program Planning:
  • The public health professional would like to have the ideal program plan accepted with enthusiasm
  • Program Planning is the community that decides to accept/reject the problem
  • Hence the community has to be well-informed about the program
• Program Operation:
  • The public health team constituting the professionals has to be employed to execute the program
• Financing:
  • Financing is a complicated mix of local, state & federal funds
  • Before starting the program public health personnel have to identify the source of funds & its management
• Program Appraisal:
  • Program Appraisal is made to assess the effectiveness of the public health program
  • The baseline data collected serves as an indicator of it
  • The dimensions used are efficiency, appropriateness, adequacy, possible side effects, etc.

Community Health Practice Questions 

Practice Of Public Health Short Question And Answers

Question 1. Medical indigence.
Answer:

Medical indigence

• Medical indigence constitutes an inability to pay large bills for medical care
• This situation is chiefly found in the case of chronic diseases such as cancer as the treatment procedures are expensive
• As an aid to the medically indigent, the concept has arisen that health care is a right of citizenship and hence to be provided by the government to the extent available
• Public health dentistry makes oral health care available to every individual irrespective of their socio-economic status by obtaining governmental and non-governmental funding

Infection Definitions

Definition of Health: Health is a state of complete physical, mental, and social well-being and not merely the absence of disease or infirmity

Agent Definition: Agent is defined as “an organism, a substance or a force, the presence or lack of which may initiate a disease process or may cause it to continue”

Host Definition: A host is defined as “a person or an animal that affords subsistence or lodgement to an infectious agent under natural conditions

Sensitivity Definition: Defined as the ability of a test to identify correctly all those who have the disease i.e. true positive

Specificity Definition: Defined as the ability of a test to identify correctly those who do not have the disease i.e. true negative

Morbidity Definition: WHO has defined it as “any departure, subjective or objective, from a state of physiological well-being”

Mortality Definition: Mortality is the condition of being mortal, or susceptible to death

Incubation Period Definition: Incubation Period is the time interval between invasion by an infectious agent and the appearance of the first sign or symptom of the disease in question

Risk Factor Definition: A risk Factor is an attribute/ exposure that is significantly associated with the development of disease.

Infection Definitions Mcqs

Latent Period Definition: A latent Period is a period between the disease initiation to the disease detection.

Disease Definition: Webster defined disease as “a condition in which the body’s health is impaired, a departure from a state of health, an alteration of the human body interrupting the performance of vital functions”.

Spectrum Of Disease Definition: Spectrum Of Disease may be defined as the sequence of events that occur in the human host from the time of contact with the etiological agent upto the point of the ultimate outcome, which may be fatal in extreme cases

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Carrier Definition: A carrier is defined as an infected person or animal that harbors a specific infectious agent in the absence of a discredible clinical disease and serves as a potential source of infection for others.

Screening Definition: Screening is defined as the use of presumptive methods to identify unrecognized health risk factors or asymptomatic diseases in persons determined by prior studies to be potentially at elevated risk & able to benefit from interventions performed before overt symptoms develop.

Infection Important Notes

1. Screening for lung cancer includes two techniques: chest radiograph and sputum cytology
2. The main causes of maternal mortality rate are hemorrhage, sepsis, abortion, obstructed labor, and hypertensive disorders.
3. Modes of transmission of disease
   1. Direct Transmission
      • Direct contact
      • Droplet infection
      • Contact with soil
      • Inoculation into skin and mucosa
      • Transplacental
   2. Indirect Transmission
      • Vehicle borne
      • Vector-borne
      • Airborne
      • Fomite borne
      • Unclean hands and fingers

4. Various measures used to evaluate screening test

1. Sensitivity
2. Specificity
3. Positive predictive value
4. Negative predictive value

5. Positive predictive value indicates the probability that a patient with a positive result has the disease. Negative predictive- it is a test to correctly exclude the disease

Infection Types Questions And Answers

6. Types of carriers:

1. Incubatory Carrier
   • These carriers shed infectious agents during the incubation period of the disease.
   • Examples: Measles, mumps, polio, pertussis
2. Convalescent Carriers
   • Shed the disease agent during the period of recovery from illness.
   • Examples: Typhoid, cholera, diphtheria
3. Healthy Carriers
   • Emerge from subclinical cases.
   • Examples: polio, cholera, diphtheria
4. Temporary Carriers
   • Shed the infectious agent for short periods of time.
   • Examples: incubatory, convalescent, and healthy carriers.
5. Chronic Carriers
   • Excretes the infectious agent for indefinite periods.
   • Examples: typhoid, hepatitis B, malaria, and gonorrhea.

Infection Long Essays

Question 1. Define Health. Enumerate the various environmental factors necessary for the maintenance of the general health of the individual.
Answer:

Health Definition: Health is a state of complete physical, mental & social well-being & not merely the absence of disease or infirmity

• The environment is the source of the agents of disease
  • Health helps in the transmission of agents to the host
  • Health may be favorable to the man & unfavorable to the agent or vice versa

Types Of Environments:

1. Internal Environment:

• Internal Environment pertains to each and every component part, every tissue, organ & organ system & their harmonious functioning within the system
• A defect or deficiency in the functioning of one or more component parts results in disease of the individual

2. External Environment:

• External Environment comprises all that is external to the individual human host
• External Environment comprises an individual’s lifestyle
• When the individual is well-adjusted, he is in a state of health
• The imbalance of the body is responsible for disease

Components:

Physical Component: It comprises nonliving things & physical factors of man’s surroundings

3. Biological environment: It includes living things surrounding man including the man himself

4. Social environment:

• The social environment comprises all human beings around man, their activities, and interactions
• Social environment includes
  1. Social factors
     • Social factors pertain to the society in which man lives
     • Social factors affect the physical, mental & social state of man which he must adjust
  2. Economic factors
     • Economic factors determine the economic status of man
     • Low economic status means less diet, poor housing, and fewer resources for medical aid

Infection Short Essays

Question 1. Epidemiological triad
Answer:

Epidemiological triad

1. The occurrence of any disease is determined by the interaction between the agent, host & environment constituting epidemiological triad

Agent:

• The agent is defined as “an organism, a substance or a force, the presence or lack of which may initiate a disease process or may cause it to continue”

1. Agent is classified as

• Biological agents: Example: bacteria, viruses, fungi
• Non-living agents
• Nutrient agents: Example: protein, fat, water

1. Chemical agents
   • External: lead, arsenic
   • Internal: urea, ketone
2. Physical agents: heat, cold, pressure
   • Mechanical agents: chronic friction
   • Social agents: smoking, poverty, isolation

Host:

• The host is defined as “a person or an animal that affords subsistence or lodgement to an infectious agent under natural conditions

1. Host factors are classified as:

• Demographic characteristics: age, sex
• Biological characteristics: genetics, immunity
• Socio-economic characteristics: Education
• Lifestyles characteristics: living habits, food habits

Environment:

• Environment is a reservoir for the agent of diseases

Components: refer to the previous question

Types Of Infection Mcqs

Question 2. Changing concepts of health.
Answer:

Changing concepts of health

1. Biomedical concept:

• According to it, health is viewed as an “absence of disease
• The biomedical concept is based on the Germ theory of disease
• This concept was found inadequate as it does not take into consideration environmental social and cul-subjective or cultural determinants of health

2. Ecological concept:

• According to it, health is viewed as a dynamic equilibrium between man and his environment and disease is a maladjustment of the human organism to the environment
• The ecological concept focuses on imperfect man and imperfect environment

3. Psychosocial concept:

• According to it, health is influenced by social, psychological, cultural, economic & political factors

4. Holistic concept:

• It implies that all sectors of society have an effect on health
• Health implies a sound mind, a sound body, and a sound family, in a sound environment

Question 3. Sensitivity & specificity.
Answer:

Sensitivity:

• Introduced by Yerushalmy in the 1940s
• Defined as the ability of a test to identify correctly all those who have the disease i.e. true positive

Specificity:

• Defined as the ability of a test to identify correctly those who do not have the disease i.e. true negative

Inter-Relation

• Sensitivity may be increased only at the cost of specificity and vice versa

Significance:

• An ideal screening test should be 100% sensitive and 100% specific

Evaluation:

• Sensitivity(true positive) = a/(a+c)*100
• Specificity (true negative) = d/(b+d)*100
  • a = that individual found positive on the test who has the condition/disorder
  • b= those who have a positive test result but do not have the disease
  • c=hose with negative results but who have the disease
  • d = those with negative results but do not have the disease

Question 4. Morbidity & mortality. disease”
Answer:

Morbidity:

• WHO has defined it as “any departure, subjective or objective, from a state of physiological well-being”

1. Morbidity is based on

• Persons who are ill
• The illnesses/diseases these people experienced
• The duration of these illnesses/disease

2. Morbidity Uses:

• Describe the extent & nature of the disease
• Provide more comprehensive, accurate, and clinically relevant information on patient characteristics
• Serve as a starting point for etiological studies
• Monitor and evaluate disease control activities

3. Morbidity Rates:

• Incidence & prevalence
• Notification rates
• Attendance rates at the out-patient department
• Admission, readmission and discharge rates
• Duration of stay in hospital
• Spells of sickness/absence from work

Mortality:

• Mortality is the condition of being mortal, or susceptible to death

1. Measures of Mortality:

• Crude death rate
  1. The crude death rate is defined as “the number of deaths per 1000 people in a population in a given year”
     • Age-specific death rate
  2. Crude death rate is the death rate specific to a given age group
     • Case fatality rate
  3. Crude death rate represents the killing power of disease
     • Proportional mortality rate
  4. The crude death rate is defined as “the number of deaths due to a particular cause per 100 or 1000 total deaths”

Question5. Greek medicine.
Answer:

Greek medicine

• In Greek medicine, Hippocrates is called the “Father of medicine”
• He studied and classified diseases based on observation and reasoning
• The Hippocratic concept of health & disease stresses the relationship between man & the environment
• Greeks gave a new direction to medical thought
• They rejected the supernatural theory of disease & looked upon disease as a natural process, not a visitation from God
• Hippocrates initiated the application of clinical methods in medicine

Infection Control Definitions

Question 6. Screening for oral diseases.
Answer:

Screening for oral diseases Definition:

• Screening for oral diseases is defined as the use of presumptive methods to identify unrecognized health risk factors or asymptomatic disease in persons determined by prior studies to be potentially at elevated risk & able to benefit from interventions performed before overt symptoms develop

Screening for oral diseases Criteria:

1. Acceptability:

• The screening test should be acceptable to the people at whom it is aimed
• Tests that are painful, discomforting, and embarrassing are not likely to be acceptable

2. Repeatability:

• The test must give consistent results when repeated more than once on the same individual/ material, under the same condition
• It depends upon observer variation, biological variation & errors relating to technical methods

3. Validity:

• Validity expresses the ability of the test to separate or distinguish those who have disease from those who do not

Screening for oral diseases Uses:

• Case detection
• Control of diseases
• Research purposes
• Screening for oral diseases provides opportunities for public awareness

Question 7. Indicators of health.
Answer:

Indicators of health Uses:

• Measures the health status of a community
• Compare the health status of one country with that of another
• Assess the health care needs
• Allocate scarce resources
• Monitor and evaluate health services
• Help to measure the extent of achievement of objectives of the programs

Indicators of health Characteristics:

• The ideal indicator should be
• Valid
• Reliable
• Sensitive
• Specific
• Feasible
• Relevant

Classification of Indicators of Health:

• Mortality indicator
  • Crude death rate
  • Expectations of life
• Morbidity indicator
• Disability rates
  • Event-type indicator
  • Person-type indicator
• Nutritional status indicator
  • Anthropometric Measurement of Preschool Children
  • Heights of children at school entry
  • Prevalence of low birth weight
• Healthcare delivery indicator
  • Doctor-population ratio
  • Doctor-nurse ratio
  • Population-bed ratio
  • Population per health/subcentre
  • Population per traditional birth attendant
• Utilization rates
  • It is the proportion of people in need of a service who actually receive it in a given period usually a year
• Indicators of social and mental health
• Environmental indicator
• Socio-economic indicator
  • Rate of population increase
  • Level of unemployment
  • Family size
• Health policy indicator
• Indicators of quality of life
  • Infant mortality
  • Life expectancy at age one
  • Literacy
• Other indicators
  • Social indicator
  • Basic needs indicator
  • Health for all indicator

Infection Classification Questions

Infection Short Question And Answers

Question 1. Determinants of health.
Answer:

The determinants of health include

1. Social and economic status:

• Higher-income and social status are linked to better health
• The greater the gap between the richest and poorest, the greater the differences in health

2. Education: Low education levels are linked with poor health, more stress, and lower self-confidence

3. Physical environment: Safe water and clean air, healthy workplaces, safe houses, and community and roads all contribute to good health

4. Personal behavior and coping skills: Balanced eating, keeping active, smoking, drinking, and how we deal with life’s stresses and challenges all affect health

Question 2. Risk factor.
Answer:

Risk factor

1. Risk factor means:

• An attribute/exposure that is significantly associated with the development of a disease
• The presence of a risk factor does not imply that the disease will occur and in its absence, the disease will not occur
• A combination of risk factors in the same individual may be purely additive/synergetic
• Risk factors may be truly causative or merely con- tributary or they may be predictive only in a statistical sense
• Some risk factors ex. Smoking can be modified while others like age, and sex cannot be modified

2. Risk factor Significance:

• Risk factors will help in the prevention and intervention of disease
• Risk factors may characterize the individual, the family, the community, and the environment

Question 3. A holistic view of health.
Answer:

A holistic view of health

• A holistic view of health implies that all sectors of society have an effect on health
• Health implies a sound mind, a sound body, and a sound family, in a sound environment

Question 4. Iceberg phenomenon.
Answer:

Iceberg phenomenon

According to the iceberg phenomenon, disease in a community may be compared to an iceberg

Tip Of Iceberg: Represents what the physician sees in the community i.e. clinical cases

1. Vast Submerged Portion:

• Represent latent, inapparent, presymptomatic, and undiagnosed cases
• The Vast Submerged Portion is an important part as many inapparent infections can be transmitted and can produce disease in others

2. Water Line: Water Line represents the demarcation between apparent & inapparent disease

Communicable Vs Non-Communicable Mcqs

Question 5. Sullivan index.
Answer:

Sullivan index

1. Sullivan index is calculated by subtracting from the life expectancy the probable duration of bed disability and inability to perform major activities
2. Sullivan index is based on cross-sectional data

Question 6. Incubation period.
Answer:

Incubation period

1. The incubation period is the time interval between invasion by an infectious agent & appearance of the first sign or symptom of the disease in question
2. An infection becomes apparent only after a certain incubation period
3. During the incubation period, the infectious agent undergoes multiplication in the host
4. When a sufficient density of the disease agent is built up in the host, the health equilibrium is disturbed & the disease becomes overt
5. The incubation period is the first stage of infectious disease
6. The incubation period of non-infectious disease may be months/years.

Question 7. True positive.
Answer:

True positive

1. True positive denotes those individuals found positive on the test, who have the condition/disease/ disorder being studied
2. True positive is denoted as ‘a in screening for diseases.

Question 8. Latent period.
Answer:

Latent period

1. The latent period is defined as “the period from disease initiation to disease detection”
2. The latent period is used in case of non-infectious disease as Incuba- the time period is used in case of infectious disease

Question 9. The germ theory of disease.
Answer:

The germ theory of disease

1. The germ theory of disease proposes that micro-organisms are the cause of many diseases
2. Dr. John Snow contributed to the formation of it
3. The germ theory of disease is generally referred to as the one-to-one relationship between causal agent & disease
   • Disease agent man→ disease
4. The emphasis had shifted from empirical causes to microbes as the sole cause of the disease

Definitions Of Infection Quiz

Question 10. A spectrum of disease.
Answer:

A spectrum of disease

1. A spectrum of disease may be defined as the sequence of events that occur in the human host from the time of contact with the etiological agent upto the point of the ultimate outcome, which may be fatal in extreme cases
2. At one end of the disease spectrum are subclinical infections and at the other end are fatal illnesses
3. In the middle of the spectrum lie illnesses ranging in severity from mild to severe
4. The sequence of events in the spectrum of disease can be interrupted by early diagnosis & treatment or by preventive measures

Question 11. Define Health.
Answer:

Health

• Health is a state of complete physical, mental & social well-being & not merely the absence of disease or infirmity

Question 12. Define Disease.
Answer:

Disease

Webster defined disease as “a condition in which the body’s health is impaired, a departure from a state of health, an alteration of the human body interrupting the performance of vital functions”.

Basic Infection Terminology Mcqs

Question 13. World Health Day.
Answer:

World Health Day

• The Constitution of WHO came into force on 7th April 1948
• So it is celebrated as World Health Day
• Every year a theme is selected and global attention is focused on that particular theme
• World Health Day theme of 1994 focused on oral health as ” Oral health for a healthy Life”.

Infection Viva Voce

1. World Health Day is on 7th April.
2. Zoonotic describes a disease transmitted to man through animals.
3. The airborne source of infection is the most difficult to control.