Epidemiology Practice Questions

Q: Communicability of disease is assessed by

Secondary attack rate. ***Secondary attack rate*** - The **secondary attack rate** directly measures the proportion of susceptible individuals who become infected after exposure to a primary case within a household or other closed setting, making it a direct indicator of **communicability**. - It quantifies the spread of disease from an existing case to close contacts, specifically reflecting how easily a pathogen transmits. *Incubation period* - The **incubation period** is the time from exposure to a pathogen to symptom onset, which indicates the latency of disease, not its communicability. - While it helps in case tracing and surveillance, it doesn't directly measure how easily the disease spreads from one person to another. *Serial interval* - The **serial interval** is the time between symptom onset in an infected person and symptom onset in a person infected by them; it reflects the pace of an epidemic but doesn't quantify transmissibility. - While related to transmission dynamics, it's not a direct measure of how likely an exposed person is to get sick. *Generation time* - **Generation time** is the average time between infection in a primary case and infection in a secondary case, providing a measure of the pathogen's intrinsic rate of spread. - It is similar to serial interval but focuses on infection times rather than symptom onset, and like the serial interval, it contributes to understanding disease dynamics but isn't as direct a measure of communicability as the secondary attack rate.

Q: All of the following are components of primordial prevention EXCEPT

Immunization. ***Immunization*** - **Immunization** is a component of **primary prevention**, aiming to prevent the onset of disease in healthy individuals. - Primordial prevention focuses on preventing the establishment of risk factors themselves, rather than preventing the disease directly. *Behavioural changes* - **Behavioural changes**, such as encouraging healthy lifestyles from a young age, are central to primordial prevention. - The goal is to prevent the adoption of unhealthy behaviours that could lead to disease later in life. *Health education* - **Health education**, particularly in early life stages, is a key strategy for primordial prevention. - It helps in fostering healthy habits and promoting awareness before risk factors emerge. *Nutritional education* - Providing **nutritional education** to prevent the development of poor dietary habits is a core aspect of primordial prevention. - This aims to prevent the establishment of risk factors like obesity and hypertension from an early age.

Q: ICD-10 chapter 1 describes?

Infectious and parasitic diseases. ***Infectious and parasitic diseases*** - **ICD-10 Chapter 1** specifically categorizes codes related to **infectious and parasitic diseases**, ranging from A00 to B99. - This chapter covers a broad spectrum of conditions caused by microorganisms and parasites, such as bacterial, viral, fungal, and protozoal infections. *Poisoning and consequences* - **Poisoning and certain other consequences of external causes** are covered in ICD-10 Chapter 19, with codes typically ranging from T36-T65 for poisoning by drugs, medicaments, and biological substances. - This chapter focuses on injuries, poisoning, and certain other consequences of external causes, not infectious diseases. *Psychiatric diseases* - **Mental and behavioral disorders** (often referred to as psychiatric diseases) are described in ICD-10 Chapter 5, with codes ranging from F00 to F99. - This chapter includes conditions such as mood disorders, anxiety disorders, schizophrenia, and substance-related disorders. *Diseases of the nervous system* - **Diseases of the nervous system** are categorized in ICD-10 Chapter 6, with codes ranging from G00 to G99. - This chapter covers conditions affecting the brain, spinal cord, nerves, and neuromuscular junctions, such as stroke, epilepsy, and Parkinson's disease.

Q: The disability adjusted life years (DALYs) lost due to neuropsychiatric disorders are highest in -

Unipolar depressive disorders. ***Unipolar depressive disorders*** - **Unipolar depressive disorders** are the leading cause of DALYs lost among neuropsychiatric conditions globally. - This is due to their **high prevalence**, **early age of onset**, and significant impact on **functional capacity** and quality of life. *Panic disorders* - While panic disorders significantly impair an individual's quality of life, their **prevalence** and **disability burden** are generally lower than that of unipolar depressive disorders. - They tend to cause episodic, intense distress rather than chronic, pervasive functional impairment to the same extent as severe depression. *Obsessive compulsive disorder* - **OCD** can be severely disabling, but its **prevalence** is lower than that of unipolar depressive disorders. - The impact on DALYs, while substantial for affected individuals, does not reach the global burden attributed to depression. *Bipolar affective disorders* - **Bipolar affective disorders** contribute significantly to DALYs due to their chronic nature and severe episodes of mood disturbance. - However, their **prevalence** is lower compared to unipolar depressive disorders, resulting in a lower overall DALY burden globally.

Q: Disease not under integrated disease surveillance project is?

Herpes Zoster. ***Herpes Zoster*** - **Herpes Zoster**, also known as shingles, is a viral disease that is typically not included in the list of diseases under routine surveillance by the Integrated Disease Surveillance Project (IDSP) in many regions. - The IDSP primarily focuses on diseases with **epidemic potential** or high public health impact for early detection and rapid response. *Meningoencephalitis* - **Meningoencephalitis** (inflammation of the brain and meninges) is a serious condition with epidemic potential, making it a key disease for surveillance under projects like IDSP. - Early detection of clusters can help prevent widespread outbreaks and manage severe neurological outcomes. *TB* - **Tuberculosis (TB)** is a major public health concern due to its high prevalence, chronic nature, and potential for transmission, especially drug-resistant forms. - It is consistently included in surveillance programs like IDSP for consistent monitoring, case finding, and treatment adherence. *Cholera* - **Cholera** is an acute diarrheal disease with high epidemic potential due to rapid transmission, particularly in areas with poor sanitation. - It is a critical disease for surveillance to enable quick identification of outbreaks, implementation of control measures, and prevention of mass fatalities.

Q: Quarantine duration is primarily based on:

Maximum incubation. ***Maximum incubation*** - Quarantine duration is set to cover the **maximum incubation period** of a disease to ensure that individuals who are infected but asymptomatic eventually develop symptoms and can be isolated. - This prevents potentially infected individuals from transmitting the disease to others after their isolation period ends. *Generation time* - **Generation time** is the average time between an individual becoming infected and that individual infecting others. - While related to transmission, it's not the primary determinant for the **maximum duration an asymptomatic person could be infectious** without showing symptoms, which is the focus of quarantine. *Serial interval* - The **serial interval** is the time between symptom onset in an infected person and symptom onset in a person they infect. - Like generation time, it describes the pace of an epidemic but doesn't define the **outer limit of when an infected person might show symptoms** to determine quarantine length. *Minimum incubation period* - The **minimum incubation period** is the shortest time between exposure and symptom onset. - Relying on the minimum incubation period would lead to a quarantine that is too short, as many individuals would still be in their **asymptomatic infectious phase** after quarantine ends.

Q: Incubation period of which disease is less than 7 days?

Cholera. ***Cholera*** - Cholera has a very short incubation period, typically ranging from **a few hours to 5 days**, often within 2 to 3 days. - This rapid onset is due to the quick action of **Vibrio cholerae toxin** on the intestinal lining. *Measles* - The incubation period for measles is generally **10 to 14 days** from exposure to the onset of fever. - The characteristic rash appears several days after the initial fever. *Mumps* - Mumps typically has an incubation period of **16 to 18 days**, with a range of 12 to 25 days. - This longer period precedes the onset of symptoms like fever and **parotid gland swelling**. *Leishmaniasis* - The incubation period for leishmaniasis can be highly variable, ranging from **weeks to months or even years**, depending on the species and form of the disease (visceral, cutaneous). - This lengthy period reflects the complex life cycle of the **Leishmania parasite** within the host.

Q: Incubation period of Salmonella typhi -

3-21 days. ***3-21 days*** - The typical incubation period for **Salmonella Typhi**, the bacterium causing typhoid fever, ranges from **3 to 21 days**. - This period allows the bacteria to multiply in the host before symptoms such as fever, headache, and malaise begin to appear. *2-5 days* - This incubation period is generally too short for **typhoid fever**, which typically has a longer course due to the pathogen's systemic spread. - Shorter incubation periods are more characteristic of other forms of **salmonellosis**, such as gastroenteritis. *14-25 days* - While overlap exists, a consistent range of **14 to 25 days** tends to skew towards the longer end of the typical incubation period, potentially missing earlier presentations. - The **3-21 day range** is more commonly cited in medical literature as the average window. *0-60 days* - An incubation period of **0-60 days** is excessively broad and lacks clinical precision for **typhoid fever**. - While rare cases might fall outside the typical range, this option includes an implausible immediate onset (0 days) and an overly protracted maximum duration.

Question 1

What happens in disease elimination:

Accepted Answer

Interruption of disease transmission from large geographical areas

Answer

Global eradication of disease agent

Answer

Incidence is reduced by 10%

Answer

Prevalence is reduced by 10%

Question 2

An influenza pandemic is defined as:

Accepted Answer

A worldwide epidemic of influenza caused by a new virus strain

Answer

A localized outbreak of seasonal influenza

Answer

An annual recurrence of influenza in winter months

Answer

A gradual increase in influenza cases over several years

Question 3

Communicability of disease is assessed by

Accepted Answer

Secondary attack rate

Answer

Incubation period

Answer

Serial interval

Answer

Generation time

Question 4

All of the following are components of primordial prevention EXCEPT

Accepted Answer

Immunization

Answer

Behavioural changes

Answer

Health education

Answer

Nutritional education

Question 5

ICD-10 chapter 1 describes?

Accepted Answer

Infectious and parasitic diseases

Answer

Poisoning and consequences

Answer

Psychiatric diseases

Answer

Diseases of the nervous system

Question 6

The disability adjusted life years (DALYs) lost due to neuropsychiatric disorders are highest in -

Accepted Answer

Unipolar depressive disorders

Answer

Panic disorders

Answer

Obsessive compulsive disorder

Answer

Bipolar affective disorders

Question 7

Disease not under integrated disease surveillance project is?

Accepted Answer

Herpes Zoster

Answer

Meningoencephalitis

Answer

TB

Answer

Cholera

Question 8

Quarantine duration is primarily based on:

Accepted Answer

Maximum incubation

Answer

Generation time

Answer

Serial interval

Answer

Minimum incubation period

Question 9

Incubation period of which disease is less than 7 days?

Accepted Answer

Cholera

Answer

Measles

Answer

Mumps

Answer

Leishmaniasis

Question 10

Incubation period of Salmonella typhi -

Accepted Answer

3-21 days

Answer

2-5 days

Answer

14-25 days

Answer

0-60 days

Epidemiology — MCQs

Epidemiology — MCQs

On this page

Practice by Chapter

Want unlimited practice?