UPSC-CMS 2012 - Community Medicine Practice Questions

Q: The detection of sore throat cases in children and their treatment with Benzathine Penicillin in Community Control Programme of Rheumatic Fever/Rheumatic Heart Disease (RF/RHD) constitutes

Primary prevention of RF/RHD. ***Primary prevention of RF/RHD*** - **Early detection and treatment** of streptococcal sore throat prevents the initial episode of **acute rheumatic fever (ARF)**, thus preventing the onset of **rheumatic heart disease (RHD)**. - This intervention targets preventing the disease's **initial occurrence** by eliminating the precipitating cause. *Primordial prevention of RF/RHD* - **Primordial prevention** focuses on preventing the development of **risk factors** in the first place, often through broad social or environmental changes. - This involves strategies like improving **socioeconomic conditions** or **housing sanitation** to reduce the overall burden of streptococcal infections, rather than treating individual cases. *Tertiary prevention of RF/RHD* - **Tertiary prevention** aims to **reduce the impact** of an established disease, minimizing complications and improving quality of life. - For RF/RHD, this would involve managing **existing RHD**, such as through cardiac surgery or long-term medication, to prevent further deterioration or disability. *Secondary prevention of RF/RHD* - **Secondary prevention** involves detecting and treating a disease **early** to prevent its progression or recurrence *after* an initial episode. - In the context of RF/RHD, this would refer to **secondary prophylaxis with penicillin** given to individuals who have already had ARF to prevent subsequent attacks and progression to RHD.

Q: Which one of the following is a stomach poison for the larvae of insects of medical importance ?

Paris Green. ***Paris Green*** - **Paris Green (copper acetoarsenite)** acts as a **stomach poison** when ingested by insect larvae, particularly effective against mosquito larvae. - It is an **arsenical compound** that disrupts cellular respiration and enzyme function in the insect's digestive system. *Anti larva oil* - **Anti-larval oils** primarily act by forming a **thin film on the water surface**, preventing mosquito larvae from breathing. - This method is a **physical action** causing suffocation, rather than a stomach poison. *Pyrethrum* - **Pyrethrum** is a broad-spectrum **contact insecticide** derived from chrysanthemum flowers. - It acts on the **nervous system** of insects, causing rapid knockdown and paralysis, but is not primarily a stomach poison for larvae. *D.D.T.* - **DDT (dichlorodiphenyltrichloroethane)** is a **contact insecticide** that acts on the nervous system of insects. - It was widely used for adult mosquito control but is not typically applied as a stomach poison for larvae in a water environment.

Q: In a village, every fifth house was selected for a study. This is an example of

Systematic random sampling. ***Systematic random sampling*** - This method involves selecting subjects from a **ordered sampling frame** at regular intervals, such as every k-th item. - In this scenario, selecting every fifth house represents a fixed interval (k=5), which is characteristic of systematic random sampling. *Simple random sampling* - This method ensures that every member of the population has an **equal chance of being selected**, often through random number generation. - It does not involve a predetermined, fixed interval of selection from an ordered list. *Convenience sampling* - This technique involves selecting subjects who are **easily accessible or readily available**, without any systematic or random process. - It is prone to bias as it does not represent the entire population. *Stratified random sampling* - This method involves dividing the population into **homogeneous subgroups (strata)** and then conducting simple random sampling within each stratum. - The scenario does not describe dividing the village households into distinct subgroups before selection.

Q: In disability rates, event type indicators are the following except

Limitation of activity. ***Limitation of activity*** - While related to disability measurement, **limitation of activity** is typically classified as a **chronic disability indicator** or **impact indicator** rather than an event type indicator measured in discrete time units. - Event type indicators usually quantify disability in **specific time units (days)** representing acute episodes or events. - **Limitation of activity** describes a long-term functional status rather than countable discrete events. *Work loss days* - **Work loss days** are a standard **event type indicator** measuring days of work lost due to illness or injury. - This is a specific type of restricted activity day for the employed population. - Quantifies disability impact in discrete, countable time units (days). *Bed disability days* - **Bed disability days** directly measure severe disability events where an individual is confined to bed. - This is a classic **event type indicator** used in national health surveys. - Represents the most severe form of restricted activity days. *Number of days of restricted activity* - **Restricted activity days** are the primary **event type indicator** in disability measurement. - Quantifies days when usual activities are limited due to health conditions. - This is the broadest category of event type indicators, encompassing bed disability days and work loss days.

Q: A randomized trial comparing the efficacy of two drugs showed a difference between the two (p value < 0.05). However, in reality the drugs do not differ. This is an example of

Type I error. ***Type I error*** - A **Type I error** occurs when the **null hypothesis is incorrectly rejected**, leading to the conclusion that a significant difference exists when, in reality, there is no true difference. - In this scenario, the trial concluded a difference (p < 0.05), but the drugs are truly equivalent, which is precisely the definition of a **Type I error**. *Both type I and II error* - It is impossible to commit both a **Type I** and a **Type II error** simultaneously for the same statistical test. - A **Type I error** involves rejecting a true null hypothesis, while a **Type II error** involves failing to reject a false null hypothesis. *Random error* - **Random error** refers to unpredictable fluctuations in measurements or results, which can be minimized but not eliminated. - While random error can contribute to variability in data, it is not the direct statistical error of concluding a non-existent difference when analyzing the results, which is a **Type I error**. *Type II error* - A **Type II error** occurs when the **null hypothesis is incorrectly accepted** (or not rejected), meaning a real difference exists but the study fails to detect it. - This scenario describes the opposite: a difference was detected and concluded, but it was false.

Q: Which one of the following formulae is used for computing the Aedes aegypti Index at International Airports and sea ports ?

Number of containers positive for Aedes aegypti breeding / Total number of containers x 100. ***Number of containers positive for Aedes aegypti breeding / Total number of containers x 100*** - The **Aedes Index (or Container Index)** specifically measures the percentage of water-holding containers found with *Aedes aegypti* larvae or pupae. - This index is crucial for assessing the **risk of dengue, Zika, and chikungunya transmission** by identifying breeding sites in areas like airports and seaports. *Number of houses positive for Aedes aegypti breeding / Total number of houses x 100* - This formula represents the **House Index**, which is a different measure of *Aedes aegypti* infestation, focusing on the percentage of houses with breeding sites. - While relevant, it is not the primary index used to assess risk at **international transit points** where containers are critical. *Number of bites of Aedes aegypti / Total number of man hours x 100* - This formula relates to **human biting rates** or **landing rates**, which assess adult mosquito activity and exposure, not the presence of breeding sites. - It does not directly measure the **potential for larval development** in containers. *Number of containers positive for Aedes aegypti breeding / Total number of houses x 100* - This formula mixes two different denominators: **containers (for positives)** and **houses (for total)**. - This is an **incorrect or hybrid formula** that does not correspond to any standard entomological index for *Aedes aegypti*.

Question 1

The detection of sore throat cases in children and their treatment with Benzathine Penicillin in Community Control Programme of Rheumatic Fever/Rheumatic Heart Disease (RF/RHD) constitutes

Accepted Answer

Primary prevention of RF/RHD

Answer

Primordial prevention of RF/RHD

Answer

Tertiary prevention of RF/RHD

Answer

Secondary prevention of RF/RHD

Question 2

Which one of the following is a stomach poison for the larvae of insects of medical importance ?

Accepted Answer

Paris Green

Answer

Anti larva oil

Answer

Pyrethrum

Answer

D.D.T.

Question 3

In a village, every fifth house was selected for a study. This is an example of

Accepted Answer

Systematic random sampling

Answer

Simple random sampling

Answer

Convenience sampling

Answer

Stratified random sampling

Question 4

In disability rates, event type indicators are the following except

Accepted Answer

Limitation of activity

Answer

Work loss days

Answer

Bed disability days

Answer

Number of days of restricted activity

Question 5

A randomized trial comparing the efficacy of two drugs showed a difference between the two (p value < 0.05). However, in reality the drugs do not differ. This is an example of

Accepted Answer

Type I error

Answer

Both type I and II error

Answer

Random error

Answer

Type II error

Question 6

Which one of the following formulae is used for computing the Aedes aegypti Index at International Airports and sea ports ?

Accepted Answer

Number of containers positive for Aedes aegypti breeding / Total number of containers x 100

Answer

Number of houses positive for Aedes aegypti breeding / Total number of houses x 100

Answer

Number of bites of Aedes aegypti / Total number of man hours x 100

Answer

Number of containers positive for Aedes aegypti breeding / Total number of houses x 100

UPSC-CMS 2012 — Community Medicine