NEET-PG 2015 - Community Medicine PYQs Practice Questions

Q: In hospital infection control, which instrument is used to monitor humidity levels to prevent nosocomial infections?

Hygrometer. ***Hygrometer*** - A **hygrometer** is specifically designed to measure **humidity** or the moisture content in the atmosphere. - Maintaining optimal **humidity levels** (typically 30-60%) is crucial in hospitals to control the spread of **pathogens** and prevent nosocomial infections. *Barometer* - A **barometer** measures **atmospheric pressure**, which is important for weather forecasting but not directly for hospital infection control. - It does not provide information about the moisture content in the air. *Anemometer* - An **anemometer** is used to measure **wind speed**, which is irrelevant to monitoring indoor environmental conditions for infection control. - It does not provide any data related to air humidity. *Thermometer* - A **thermometer** measures **temperature**, which is a separate environmental parameter from humidity. - While temperature control is important in healthcare settings, it does not directly monitor moisture content. [Practice more Community Medicine PYQs on OnCourse]

Q: Consanguineous marriages increase the risk of which of the following diseases?

Autosomal recessive diseases. ***Autosomal recessive diseases*** - Consanguineous marriages increase the likelihood of offspring inheriting two copies of a **recessive deleterious allele** from a common ancestor. - This significantly raises the risk of expressing **autosomal recessive conditions**, as both parents are more likely to be carriers of the same rare recessive gene. - Examples include **thalassemia, sickle cell disease, and cystic fibrosis**. *Autosomal dominant diseases* - These diseases manifest with only **one copy of the mutated allele**, regardless of consanguinity. - The risk is primarily linked to whether one parent carries the dominant gene, not the relatedness of the parents. *X linked dominant diseases* - These conditions are caused by mutations on the **X chromosome** and are expressed dominantly. - Consanguinity does not specifically increase the risk, as the disease manifests when the mutated X-linked gene is inherited from an affected parent. - The inheritance pattern depends on the affected parent's sex, not on parental relatedness. *Environmental diseases* - These diseases are primarily caused by **external factors** such as toxins, diet, lifestyle choices, or infections. - While genetic predisposition may play a role, consanguinity does not directly increase the risk for environmentally triggered diseases. [Practice more Community Medicine PYQs on OnCourse]

Q: Which blinding technique is considered the most effective in clinical trials?

Double blinding. **Double blinding** - Involves both the **participants** and the **researchers/investigators** being unaware of the treatment assignment. - This method effectively minimizes bias from both **subject expectation** (placebo effect) and **observer expectation** (detection bias). *Single blinding* - Only the **participant** is unaware of the treatment they are receiving, while the investigator knows. - While it reduces participant bias, it can still introduce bias from the investigator regarding **outcome assessment** or **patient interaction**. *Triple blinding* - Extends blinding to include the **data analyst** who is also unaware of the treatment assignments during analysis. - While theoretically offering an additional layer of protection against bias, its practical benefits over double blinding are often marginal and it's less commonly implemented due to **complexity**. *No blinding* - Both the **participants** and the **researchers** are aware of the treatment assignments (open-label study). - This approach is highly susceptible to **bias** from both participant and researcher expectations, significantly compromising the study's validity and reliability. [Practice more Community Medicine PYQs on OnCourse]

Q: Randomization is done to reduce?

Selection bias. ***Selection bias*** - **Randomization** ensures that each participant has an equal chance of being assigned to any study group, which helps to distribute both known and unknown confounding factors evenly. - This process minimizes **selection bias** by promoting comparability between groups, making it more likely that any observed differences are due to the intervention rather than pre-existing differences. *Recall bias* - **Recall bias** occurs when there are systematic differences in the way participants remember or report past exposures or events, often seen in retrospective studies. - While randomization helps control for confounding, it does not directly prevent participants from inaccurately recalling information. *Berksonian bias* - **Berksonian bias** is a form of selection bias where the probability of being admitted to a hospital (or selected into a study) is affected by the presence of a co-morbidity, leading to a distorted association between diseases. - Randomization aims to balance characteristics *within* the study groups once participants are recruited, but it doesn't address biases related to the initial selection into the study population from a larger source. *Reporting bias* - **Reporting bias** refers to selective revealing or suppression of information, either by study participants (e.g., social desirability bias) or by researchers (e.g., only reporting positive findings). - Randomization helps ensure internal validity by creating comparable groups, but it does not prevent individuals from selectively reporting outcomes or experiences. [Practice more Community Medicine PYQs on OnCourse]

Q: The strongest occupational risk factor for hematological carcinoma is

Benzene. ***Benzene*** - Benzene exposure is recognized as a potent **carcinogen** linked to various hematological malignancies, including **leukemia** [1]. - It affects the **bone marrow**, leading to dysplastic changes and ultimately malignancy. *Nicotine* - Although nicotine is associated with **smoking-related cancers**, it is not directly linked to **hematological carcinomas**. - Its primary role is in causing **lung cancer**, rather than blood cancers. *Lithium* - Lithium is primarily used for **bipolar disorder** and does not have a known link to causing hematological malignancies. - Side effects are more related to **nephrotoxicity** rather than carcinogenic effects. *Alcohol* - Alcohol consumption is primarily associated with **liver cancers** and not specifically linked to hematological carcinomas [2]. - It can contribute to general malignancy development but is not a direct cause of blood cancers. **References:** [1] Kumar V, Abbas AK, et al.. Robbins and Cotran Pathologic Basis of Disease. 9th ed. Neoplasia, p. 286. [2] Cross SS. Underwood's Pathology: A Clinical Approach. 6th ed. (Basic Pathology) introduces the student to key general principles of pathology, both as a medical science and as a clinical activity with a vital role in patient care. Part 2 (Disease Mechanisms) provides fundamental knowledge about the cellular and molecular processes involved in diseases, providing the rationale for their treatment. Part 3 (Systematic Pathology) deals in detail with specific diseases, with emphasis on the clinically important aspects., pp. 217-218. [Practice more Community Medicine PYQs on OnCourse]

Question 1

In hospital infection control, which instrument is used to monitor humidity levels to prevent nosocomial infections?

Accepted Answer

Hygrometer

Answer

Barometer

Answer

Thermometer

Answer

Anemometer

Question 2

Consanguineous marriages increase the risk of which of the following diseases?

Accepted Answer

Autosomal recessive diseases

Answer

Autosomal dominant diseases

Answer

X linked dominant diseases

Answer

Environmental diseases

Question 3

Which blinding technique is considered the most effective in clinical trials?

Accepted Answer

Double blinding

Answer

Triple blinding

Answer

No blinding

Answer

Single blinding

Question 4

Randomization is done to reduce?

Accepted Answer

Selection bias

Answer

Recall bias

Answer

Berksonian bias

Answer

Reporting bias

Question 5

The strongest occupational risk factor for hematological carcinoma is

Accepted Answer

Benzene

Answer

Lithium

Answer

Radiation exposure

Answer

Cigarette smoke

Question 6

Caisson's disease is primarily associated with which of the following?

Accepted Answer

Underwater construction workers

Answer

None of the options

Answer

Rapid ascent in aircraft

Answer

Rapid ascent of deep sea divers

Question 7

What is the most common mode of transmission of HIV?

Accepted Answer

Sexual contact

Answer

Occupational exposure (needle stick injury)

Answer

Perinatal transmission (mother to child)

Answer

Transmission via blood and blood products

Question 8

Which of the following is NOT one of Bradford Hill's criteria for causation?

Accepted Answer

Absence of temporal relationship

Answer

Consistency of association

Answer

Specificity of association

Answer

Strength of association

Question 9

What is the definition of a reservoir in the context of infectious diseases?

Accepted Answer

Person, animal or substance in which infectious agent lives and multiplies

Answer

Person, animal or object from which infectious agent is transmitted to host

Answer

Person or animal in which infectious agent causes a disease

Answer

Person or animal that transmits the infectious agent mechanically

Question 10

Which of the following is not true about the Vi polysaccharide vaccine for typhoid?

Accepted Answer

Given at birth

Answer

Given intramuscularly

Answer

Revaccination at 3 years

Answer

Single dose is given

NEET-PG 2015 — Community Medicine