NEET-PG 2015 - Community Medicine Practice Questions

Q: In a community of 1,000,000 population, 105 children were born in a year, out of which 5 were stillbirths and 4 died within the first year of life. What is the Infant Mortality Rate (IMR)?

40. ***40*** - **Infant Mortality Rate (IMR)** = (Deaths in first year of life / Live births) × 1,000 - Live births = Total births - Stillbirths = 105 - 5 = **100** - IMR = (4 / 100) × 1,000 = **40 per 1,000 live births** - Stillbirths are excluded from both numerator and denominator as IMR only counts deaths after live birth *90* - This would result from incorrectly using total births (105) instead of live births (100) in the denominator - Wrong calculation: (4 / 105) × 1,000 ≈ 38, not 90 - This option represents a common error but with incorrect arithmetic *120* - This could result from including stillbirths in the numerator: (5+4) / 100 × 1,000 = 90, not 120 - Or from other miscalculations mixing up the numerator and denominator - Does not follow the standard IMR formula *150* - This represents a significant calculation error - May result from using wrong base (per 100 instead of per 1,000) or including stillbirths incorrectly - Such high IMR does not match the given data of 4 infant deaths per 100 live births

Q: Bladder cancer can occur in those who are working in dye industry for 25 years. Which study design is most appropriate for establishing a causal relationship between dye industry work and bladder cancer?

Cohort study. ***Cohort study*** - A **cohort study** tracks a group of individuals exposed to a risk factor (dye industry work) and a group not exposed over time to see who develops the outcome (bladder cancer). - This design allows for the calculation of **incidence rates** and relative risk, which are crucial for establishing a causal link, especially when the exposure is rare or specific. - Cohort studies establish **temporal relationship** (exposure precedes disease) and can demonstrate a **dose-response relationship**, both essential for proving causality. *Cross-sectional study* - A **cross-sectional study** assesses exposure and outcome simultaneously at a single point in time, making it difficult to determine the temporal sequence of events. - While it can identify associations, it cannot definitively establish a **cause-and-effect relationship** because it doesn't observe outcomes developing over time. *Case-control study* - A **case-control study** compares individuals with the outcome (cases) to individuals without the outcome (controls) and retrospectively looks for differences in past exposures. - While useful for studying **rare diseases** and can suggest associations, it is prone to **recall bias** regarding exposure history and cannot establish causality as definitively as cohort studies. *Randomized control trial* - A **randomized controlled trial (RCT)** involves randomly assigning participants to an intervention group or a control group and following them prospectively. - While RCTs provide the strongest evidence for causality, it would be **unethical** to intentionally expose people to a known carcinogen like dye industry chemicals for research purposes.

Q: Which of the following statements regarding polio vaccination is false?

First OPV is given at 4 weeks. ***First OPV is given at 4 weeks*** - The first dose of **Oral Polio Vaccine (OPV)** is typically given at birth, often referred to as the **"zero dose,"** before the 4-week mark. - Subsequent doses are given at 6, 10, and 14 weeks of age as part of the routine immunization schedule, making the statement that the first OPV is given at 4 weeks false. *OPV induces both humoral and intestinal immunity* - **OPV** is a **live attenuated vaccine** that replicates in the gut, thereby stimulating both a systemic **humoral immune response** (producing antibodies in the bloodstream) and **local intestinal immunity** (IgA antibodies in the gut). - This **intestinal immunity** is crucial for preventing viral replication in the gut and reducing transmission. *IPV is given intramuscularly* - The **Inactivated Polio Vaccine (IPV)**, also known as the **Salk vaccine**, is administered via injection, specifically through the **intramuscular route**. - This method ensures systemic absorption and the development of **humoral immunity**. *Both killed and live vaccines are available* - There are two main types of polio vaccines: **Oral Polio Vaccine (OPV)**, which is a **live attenuated vaccine**, and **Inactivated Polio Vaccine (IPV)**, which is a **killed vaccine**. - Both types have been instrumental in polio eradication efforts, each with distinct advantages and disadvantages.

Q: Behavioral surveillance survey is done in?

AIDS. ***AIDS*** - Behavioral surveillance surveys are crucial for understanding and monitoring behaviors related to **HIV transmission**, such as sexual practices and drug use, among at-risk populations. - These surveys help in designing and evaluating **prevention programs** by identifying trends in risky behaviors and knowledge, attitudes, and practices (KAP) concerning HIV. *Filaria* - Surveillance for filaria primarily involves **entomological surveys** (mosquito monitoring) and **parasitological surveys** (blood examinations for microfilariae). - Behavioral aspects are less central to direct surveillance compared to disease vectors and infection rates. *TB* - Tuberculosis surveillance mainly focuses on **case detection**, **treatment outcomes**, and monitoring **drug resistance** through clinical and laboratory data. - While patient adherence to treatment involves behavior, there isn't a dedicated "behavioral surveillance survey" method specifically for TB. *Malaria* - Malaria surveillance involves monitoring **parasitemia rates**, **vector populations**, and **antimalarial drug resistance**. - Behavioral components like bed net usage are important, but the primary surveillance methods are not termed "behavioral surveillance surveys" in the same structured way as for HIV.

Q: Which of the following vaccines is not freeze-dried?

Diphtheria, Pertussis, and Tetanus (DPT) Vaccine. ***Diphtheria, Pertussis, and Tetanus (DPT) Vaccine*** - The DPT vaccine is a **liquid vaccine** that contains inactivated toxins and bacterial components, making it stable in liquid form. - It does not require **freeze-drying** because its components are chemically stable and do not degrade significantly in solution. *Measles Vaccine* - The measles vaccine is a **live attenuated vaccine** that needs to be freeze-dried to maintain the viability and stability of the live virus. - Freeze-drying helps preserve the vaccine's potency by removing water, which prevents degradation during storage and transport. *Rubella Vaccine* - Similar to the measles vaccine, the rubella vaccine is a **live attenuated vaccine** and is therefore provided in a freeze-dried form. - This process ensures the long-term stability and efficacy of the viral components, which would otherwise degrade in a liquid state. *BCG Vaccine* - The BCG (Bacillus Calmette-Guérin) vaccine is a **live attenuated bacterial vaccine** used against tuberculosis, and it is also manufactured as a freeze-dried product. - Freeze-drying is essential for maintaining the viability of the live attenuated *Mycobacterium bovis* strain.

Q: Drug of choice for mass therapy under filariasis control programme?

DEC. ***Correct: DEC*** - **Diethylcarbamazine (DEC)** is the drug of choice for **mass drug administration (MDA)** campaigns aimed at eliminating lymphatic filariasis. - It effectively kills **microfilariae** and has some action on adult worms, reducing transmission. - In India's National Filariasis Elimination Programme, DEC is administered along with Albendazole in annual MDA campaigns. *Incorrect: Albendazole* - While **Albendazole** is co-administered with DEC in MDA programs, it is not the sole drug of choice for mass treatment of filariasis. - Its primary role is to provide **macrofilaricidal** activity (killing adult worms) and co-treatment for other helminth infections. - It enhances the effect of DEC but is not used alone. *Incorrect: Ivermectin* - **Ivermectin** is used in MDA programs for filariasis, particularly in areas co-endemic with **onchocerciasis** or where **Loa loa** is prevalent (as DEC is contraindicated in these areas). - However, in India and most lymphatic filariasis endemic areas, **DEC** remains the primary drug. *Incorrect: Mebendazole* - **Mebendazole** is an anthelminthic primarily used for treating **intestinal nematode infections** like ascariasis, trichuriasis, and hookworm. - It is **not used** in lymphatic filariasis mass treatment programs.

Q: Reservoir of infection in enteric fever?

Man. ***Man*** - Humans are the **sole natural reservoir** for *Salmonella Typhi* and *Salmonella Paratyphi*, the causative agents of enteric fever (typhoid and paratyphoid fever). - The bacteria can persist in the **gallbladder** of asymptomatic carriers, who can then shed the bacteria in their feces, contributing to transmission. *Birds* - Birds are not considered a primary reservoir for the **causative pathogens of enteric fever** (*Salmonella Typhi* or *Paratyphi*). - They are more commonly associated with other *Salmonella* serotypes, such as *Salmonella Enteritidis*, which cause **gastroenteritis** rather than systemic enteric fever. *Cow* - Cows are not a primary reservoir for the organisms responsible for **enteric fever**; these pathogens are specifically adapted to humans. - While cows can carry various *Salmonella* species, they are typically associated with **foodborne outbreaks** of *Salmonella*-induced **gastroenteritis**, not typhoid fever. *Water* - Water is a **vehicle for transmission** of enteric fever, becoming contaminated with human feces containing *Salmonella Typhi* or *Paratyphi*. - It is not a reservoir because the bacteria do not naturally **multiply or persist indefinitely** in water without a human source.

Q: Which of the following statements about influenza infectivity is correct?

All of the options are correct.. ***All of the options are correct.*** - All statements provided accurately describe aspects of influenza infectivity and epidemiology. - The **communicable period**, the **primary source of infection**, and the potential for **subclinical cases** are all characteristic features of influenza. *Communicable period is 1 day before to 5-7 days after the onset of symptoms* - This statement is accurate, as influenza is transmissible **before symptom onset** and for several days afterward, which contributes to its rapid spread. - Peak viral shedding often occurs just before and in the first few days of symptomatic illness. - Adults typically shed virus from 1 day before to 5-7 days after symptom onset (can be longer in children and immunocompromised individuals). *The primary source of infection is a clinical case.* - This is correct, as **symptomatic individuals (clinical cases) are the PRIMARY source** of influenza virus transmission to others. - Respiratory droplets produced by coughing, sneezing, or talking from an infected person are the main mode of spread. - While subclinical cases can transmit, clinical cases with overt symptoms produce more respiratory droplets and are the major drivers of transmission. *There can be subclinical cases of influenza.* - This statement is correct; many individuals infected with influenza virus experience **mild or asymptomatic infections** (subclinical cases). - These subclinical cases can still transmit the virus, though typically to a lesser extent than symptomatic cases, further complicating control efforts.

Q: Human, animal, fomite or objects from which infective organism enters the host is called?

Source of infection. ***Source of infection*** - The **source of infection** refers to the person, animal, object, or substance from which an infectious agent passes immediately to a host. - This can include humans, animals, fomites, or contaminated objects that directly transmit the infectious organism. - This is the proximate source from which the agent enters the host. *Infective Reservoir* - An **infective reservoir** is the long-term habitat where an infectious agent normally lives, grows, and multiplies. - The reservoir can be human, animal, plant, soil, or inanimate matter where the agent is normally found. - While a reservoir can be a source, the source is specifically the immediate point from which transmission occurs. *Infective Carrier* - An **infective carrier** is an infected person or animal that harbors a specific infectious agent without showing clinical symptoms but can transmit it to others. - A carrier is a type of source (when transmission occurs from them), but the term "source" is broader, encompassing inanimate objects and fomites as well. *None of the above* - This option is incorrect because **Source of infection** accurately describes the concept presented in the question.

Question 1

In a community of 1,000,000 population, 105 children were born in a year, out of which 5 were stillbirths and 4 died within the first year of life. What is the Infant Mortality Rate (IMR)?

Accepted Answer

40

Answer

90

Answer

120

Answer

150

Question 2

Bladder cancer can occur in those who are working in dye industry for 25 years. Which study design is most appropriate for establishing a causal relationship between dye industry work and bladder cancer?

Accepted Answer

Cohort study

Answer

Cross-sectional study

Answer

Case-control study

Answer

Randomized control trial

Question 3

Multiphasic screening means-

Accepted Answer

Application of two or more screening tests in combination at one time

Answer

Application of two or more screening tests in combination at different geographical areas

Answer

Application of separate screening tests for different diseases

Answer

Application of two or more screening tests in combination at different times

Question 4

Which of the following statements regarding polio vaccination is false?

Accepted Answer

First OPV is given at 4 weeks

Answer

OPV induces both humoral and intestinal immunity

Answer

IPV is given intramuscularly

Answer

Both killed and live vaccines are available

Question 5

Behavioral surveillance survey is done in?

Accepted Answer

AIDS

Answer

TB

Answer

Filaria

Answer

Malaria

Question 6

Which of the following vaccines is not freeze-dried?

Accepted Answer

Diphtheria, Pertussis, and Tetanus (DPT) Vaccine

Answer

Measles Vaccine

Answer

Rubella Vaccine

Answer

BCG Vaccine

Question 7

Drug of choice for mass therapy under filariasis control programme?

Accepted Answer

DEC

Answer

Albendazole

Answer

Ivermectin

Answer

Mebendazole

Question 8

Reservoir of infection in enteric fever?

Accepted Answer

Man

Answer

Birds

Answer

Cow

Answer

Water

Question 9

Which of the following statements about influenza infectivity is correct?

Accepted Answer

All of the options are correct.

Answer

Communicable period is 1 day before to 5-7 days after the onset of symptoms

Answer

There can be subclinical cases of influenza.

Answer

The primary source of infection is a clinical case.

Question 10

Human, animal, fomite or objects from which infective organism enters the host is called?

Accepted Answer

Source of infection

Answer

Infective Reservoir

Answer

Infective Carrier

Answer

None of the above

NEET-PG 2015 — Community Medicine