Epidemiology Practice Questions

Q: Accidents happening during weekends is an example of -

Cyclic trends. ***Cyclic trends*** - Accidents happening during weekends represent a **regular, recurrent pattern** over a short period (weekly), which is characteristic of a cyclic trend. - These trends show peaks and troughs that occur at **predictable intervals**, such as every week or month. *Point source epidemic* - A **point source epidemic** refers to an outbreak where exposure to the causative agent is brief and simultaneous, resulting in a sharp rise and fall in cases, often from a single event or source. - This typically describes disease outbreaks following a contamination event, not recurring patterns of accidents over weekends. *Secular trends* - **Secular trends** describe long-term changes over many years or decades, showing a gradual increase or decrease in prevalence or incidence. - This concept is used for gradual shifts in health indicators over long periods, not for short-term weekly fluctuations. *Seasonal trends* - **Seasonal trends** refer to patterns that recur annually, often linked to changes in seasons, such as influenza outbreaks in winter or agricultural accidents in summer. - While weekends are a recurring interval, the pattern is weekly, not yearly, which distinguishes it from seasonal trends.

Q: What is the incubation period of Hepatitis A?

2 weeks – 2 months. ***2 weeks – 2 months*** - The incubation period for **Hepatitis A** specifically ranges from **15 to 50 days (average 28 days)**, which falls within the 2 weeks to 2 months timeframe. - This period allows for viral replication before the onset of clinical symptoms like **jaundice**, **fatigue**, and **nausea**. *6 days – 6 weeks* - This range is too broad and includes periods that are either too short or too long for the typical **Hepatitis A** incubation, although 6 weeks is close to the upper limit. - While 6 weeks does fall within the possible maximum, the lower end of 6 days is uncharacteristically short for **Hepatitis A**. *6 weeks – 6 months* - This incubation period is generally too long for **Hepatitis A**, which rarely exceeds 50 days. - Longer incubation periods, such as **6 weeks to 6 months**, are more characteristic of other viral hepatitides like **Hepatitis B** or **Hepatitis C**. *2 days – 2 weeks* - This period is generally too short for the incubation of **Hepatitis A virus**. - Such a short incubation period is more typical for **bacterial food poisoning** or other acute gastrointestinal infections rather than viral hepatitis.

Q: There has been a gradual increase in number of non-communicable disease cases as compared to previous years. This trend is called:

Secular. ***Secular*** - A **secular trend** refers to a long-term change or trend in the frequency of a disease or health condition over an extended period, often years or decades. - The gradual increase in the number of non-communicable disease cases over previous years is a classic example of a **secular trend**. *Periodical* - **Periodical** variations typically refer to patterns that repeat at regular intervals but are much shorter than long-term secular trends (e.g., daily, weekly). - This term does not capture the **long-term, evolving nature** of the health trend described. *Cyclical* - A **cyclical trend** describes fluctuations in disease incidence that occur over periods longer than a year, but still demonstrate a predictable, repeating cycle, often related to socioeconomic or environmental factors (e.g., a disease peaking every few years). - While it describes patterns, it implies **repetition** rather than a continuous, unidirectional increase over time. *Seasonal* - **Seasonal trends** describe variations in disease occurrence that are related to specific seasons of the year, such as the increase in influenza cases during winter. - This term specifically refers to **annual fluctuations** and does not describe a gradual increase over many years.

Q: Which of the following is not a criterion suggesting causality in non communicable diseases?

Lack of temporal association. ***Lack of temporal association*** - For an exposure to cause a non-communicable disease, the exposure must precede the disease onset; therefore, a **lack of temporal association** explicitly argues *against* causality. - This criterion is a fundamental principle of causality, as the **cause must occur before the effect**. *Specificity of association* - This criterion suggests that a single exposure should lead to a single disease. However, in non-communicable diseases, a single risk factor may contribute to multiple diseases (e.g., smoking and lung cancer, heart disease, stroke), and a single disease can have **multiple causes**. - While it was important in the original Bradford Hill criteria, its relevance is diminished in modern epidemiology due to the **multifactorial nature of chronic diseases**. *Dose response relationship* - This criterion implies that as the **amount or duration of exposure increases**, the **risk or severity of the disease also increases**. - This is a strong indicator of causality because it suggests a biological gradient. *Strength of association* - A strong association, often measured by a **high relative risk or odds ratio**, increases the likelihood of a causal relationship. - A weak association, while not ruling out causality, makes it less likely to be directly causal and more likely to be influenced by other factors or confounding variables.

Q: Which of the following studies has given coronary risk factors?

Framingham. ***Framingham*** - The **Framingham Heart Study** is a landmark prospective cohort study that has identified many of the well-known **risk factors for cardiovascular disease**, including hypertension, high cholesterol, smoking, and diabetes. - This ongoing study, started in 1948, has been instrumental in shaping our understanding of **coronary artery disease** development and prevention strategies. *North Karelia* - The **North Karelia Project** was a comprehensive community-based prevention program in Finland that successfully reduced cardiovascular disease risk factors. - While influential in demonstrating how to **implement prevention strategies**, it applied already-known risk factors rather than discovering new ones. - The program focused on reducing smoking, cholesterol, and blood pressure in the population. *Stanford study* - While Stanford University has conducted numerous influential medical studies, there isn't a single "Stanford study" primarily recognized for giving us the comprehensive list of coronary risk factors. - Many institutions contribute to medical knowledge, but the **Framingham Heart Study** stands out for this specific contribution. *MONICA* - The **MONICA (Monitoring Trends and Determinants in Cardiovascular Disease)** Project was a multinational WHO project that aimed to monitor cardiovascular disease trends and determinants. - While it provided valuable data on the **epidemiology of cardiovascular disease** and its risk factors, it primarily assessed trends in established risk factors rather than initially identifying them.

Q: Which of the following is a primary prevention strategy for coronary heart disease?

Salt restriction. ***Salt restriction*** - **Salt restriction** is a primary prevention strategy as it helps in maintaining healthy blood pressure, which in turn reduces the risk of **coronary heart disease (CHD)**. - By reducing **sodium intake**, the workload on the heart is decreased, preventing the development of hypertension, a major risk factor for CHD. - This is a clear, individual-level **primary prevention** measure that directly addresses a modifiable risk factor. *BP monitoring* - While important for managing and detecting hypertension, **BP monitoring** is a **secondary prevention** or screening activity, aiming to identify existing risk factors, not prevent their initial development. - It helps in early detection and management of high blood pressure, but does not prevent the underlying condition from occurring. *Exercise promotion in high risk geographical areas* - While exercise is indeed a key component of **primary prevention**, this option describes a **population-level public health strategy** rather than an individual primary prevention measure. - The question asks for "a primary prevention strategy," which typically refers to individual-level interventions in clinical/community medicine context. - **Salt restriction** is a more direct and specific individual-level answer. *All of the options* - This option is incorrect because **BP monitoring** is primarily a screening/secondary prevention measure, not a direct primary prevention strategy. - While exercise has preventive benefits, the phrasing as a population-level geographical strategy makes it less precise than **salt restriction** as the best answer.

Q: Which of the following diseases has an incubation period > 10 days

Measles. ***Correct: Measles*** - Measles has a relatively long incubation period, typically ranging from **10 to 14 days** from exposure to the onset of fever. - This extended incubation allows for significant asymptomatic spread before the classic **maculopapular rash** appears. - Among the listed options, only measles exceeds the 10-day threshold. *Incorrect: Plague* - The incubation period for **bubonic plague** is usually 2 to 6 days. - For **pneumonic plague**, the incubation period is even shorter, typically 1 to 3 days. - Both forms are well below 10 days. *Incorrect: Cholera* - Cholera has a very short incubation period, ranging from a few hours to 5 days, usually **2-3 days**. - This rapid onset is due to the toxin production in the small intestine causing severe **watery diarrhea**. *Incorrect: Influenza* - The incubation period for influenza is generally short, averaging around 2 days, and can range from **1 to 4 days**. - This short incubation period contributes to its rapid spread during outbreaks.

Q: Primary prevention does not include -

Early diagnosis and treatment. ***Early diagnosis and treatment*** - This intervention falls under **secondary prevention**, aiming to halt the progression of a disease once it has occurred. - **Primary prevention** focuses on preventing the occurrence of disease altogether, before any symptoms or disease processes begin. *Health promotion* - **Health promotion** encompasses activities that encourage healthy lifestyles and prevent disease, such as promoting proper nutrition and exercise. - These are typical examples of primary prevention, aiming to improve overall health and reduce risk factors. *Specific protection* - **Specific protection** involves targeted measures to prevent specific diseases, such as immunizations against infectious agents or using protective equipment. - This is a key component of primary prevention, as it directly reduces the likelihood of contracting a disease. *Health education* - **Health education** provides individuals and communities with knowledge and skills to make informed decisions about their health. - By promoting healthy behaviors and understanding risk factors, it functions as a foundational strategy within primary prevention.

Q: Which one of the following diseases has the shortest incubation period?

Staphylococcus food poisoning. ***Staphylococcus food poisoning*** - This condition is caused by preformed **toxins** produced by *Staphylococcus aureus* in food, leading to a very rapid onset of symptoms. - The incubation period is typically very short, ranging from **30 minutes to 6 hours** after ingestion. *Salmonella food poisoning* - Caused by the ingestion of live *Salmonella* bacteria, which then multiply in the intestines and produce toxins. - The incubation period is typically longer than staphylococcal food poisoning, ranging from **6 hours to 72 hours**. *Diphtheria* - This is a bacterial infection caused by *Corynebacterium diphtheriae*, which primarily affects the nose, throat, and sometimes skin. - The incubation period is generally between **2 to 5 days**, but can range from 1 to 10 days. *Cholera* - Caused by the bacterium *Vibrio cholerae*, which infects the small intestine and produces a potent toxin causing severe watery diarrhea. - The incubation period is variable, usually from **1 to 5 days**, often within 24-48 hours.

Question 1

Accidents happening during weekends is an example of -

Accepted Answer

Cyclic trends

Answer

Point source epidemic

Answer

Secular trends

Answer

Seasonal trends

Question 2

What is the incubation period of Hepatitis A?

Accepted Answer

2 weeks – 2 months

Answer

6 days – 6 weeks

Answer

6 weeks – 6 months

Answer

2 days – 2 weeks

Question 3

There has been a gradual increase in number of non-communicable disease cases as compared to previous years. This trend is called:

Accepted Answer

Secular

Answer

Periodical

Answer

Cyclical

Answer

Seasonal

Question 4

Which of the following is not a criterion suggesting causality in non communicable diseases?

Accepted Answer

Lack of temporal association

Answer

Specificity of association

Answer

Dose response relationship

Answer

Strength of association

Question 5

Which of the following studies has given coronary risk factors?

Accepted Answer

Framingham

Answer

Stanford study

Answer

MONICA

Answer

North Karelia

Question 6

Which of the following is a primary prevention strategy for coronary heart disease?

Accepted Answer

Salt restriction

Answer

BP monitoring

Answer

Exercise promotion in high risk geographical areas

Answer

All of the options

Question 7

Which of the following diseases has an incubation period > 10 days

Accepted Answer

Measles

Answer

Plague

Answer

Cholera

Answer

Influenza

Question 8

Primary prevention does not include -

Accepted Answer

Early diagnosis and treatment

Answer

Health promotion

Answer

Specific protection

Answer

Health education

Question 9

There are 40 new cases of carcinoma of breast per 100,000 women/ year in country 'X' & 100 new cases / 100,000 women/ year in Country 'Y'. Based on this statistical data which of the following statement is true?

Accepted Answer

Country 'X' has more number of younger women than country 'Y'

Answer

More women in Country 'Y' are smokers

Answer

More preventive & screening measures like mammography are available in Country 'X'

Answer

More women in Country 'X' had breastfed their children

Question 10

Which one of the following diseases has the shortest incubation period?

Accepted Answer

Staphylococcus food poisoning

Answer

Salmonella food poisoning

Answer

Diphtheria

Answer

Cholera

Epidemiology — MCQs

Epidemiology — MCQs

On this page

Practice by Chapter

Want unlimited practice?