UPSC-CMS 2014 - Community Medicine Practice Questions

Q: Excessive nitrates in drinking water can produce:

Methaemoglobinaemia. ***Methaemoglobinaemia*** - Nitrates are converted to **nitrites** in the gastrointestinal tract, especially in infants. Nitrites then oxidize the **ferrous iron (Fe2+)** in hemoglobin to **ferric iron (Fe3+)**, forming **methemoglobin**. - **Methemoglobin** cannot bind oxygen, leading to **cyanosis** and **tissue hypoxia**, often referred to as "blue baby syndrome" in infants. *Polycythemia vera* - This is a **myeloproliferative neoplasm** characterized by the overproduction of red blood cells, white blood cells, and platelets. - It is not caused by nitrate exposure but is rather a bone marrow disorder that can lead to symptoms like headaches, dizziness, and a ruddy complexion due to increased blood viscosity. *Hypochromic microcytic anemia* - This type of anemia is typically caused by **iron deficiency**, leading to smaller (microcytic) red blood cells with less hemoglobin (hypochromic). - It is not directly linked to excessive nitrate consumption; instead, nitrate toxicity primarily affects oxygen transport by converting hemoglobin to methemoglobin. *Hemophilia* - Hemophilia is a **genetic bleeding disorder** caused by a deficiency in specific blood clotting factors, most commonly Factor VIII or Factor IX. - It is an inherited condition and has no association with environmental factors such as nitrate levels in drinking water.

Q: The following statements are correct for healthful school environment except:

In the classroom, desks should be of minus type.. ***In the classroom, desks should be of minus type.*** - This statement is **incorrect** and is the exception. For a healthful school environment, desks should ideally be of the **'plus type'**, which means the desk overlaps the bench by at least 2 inches to allow for a comfortable and ergonomically sound seating posture, preventing slouching. - A 'minus type' desk, where the bench overlaps the desk, would lead to poor posture and discomfort, making it an unhealthful arrangement. *Combined window and door area should be 25% of the floor space.* - This statement is **correct** for optimal **ventilation and natural lighting** in a school environment. - Adequate window and door area (typically 20-25% of floor space) ensures proper air circulation and reduces reliance on artificial lighting, contributing to a healthier learning space. *Per capita space for each student should be 6 sq. feet.* - This statement represents an **acceptable minimum per capita space requirement** for students in a classroom according to traditional standards. - Providing sufficient space (minimum 6 sq ft, though 8-10 sq ft is preferred by modern guidelines) prevents overcrowding, allows for mobility, and ensures a comfortable learning environment. *One urinal should be provided for 60 students.* - This statement reflects an **accepted standard** for the **provision of sanitation facilities** in schools. - Adequate numbers of urinals and toilets (ratio of 1:50-60) are crucial for maintaining hygiene, preventing long queues, and ensuring accessibility for students.

Q: What is the most important test to assess the prevalence of tuberculosis infection in a community?

Tuberculin test. ***Tuberculin test*** - The **tuberculin skin test (TST)**, or Mantoux test, measures the delayed-type hypersensitivity reaction to tuberculin, indicating prior exposure to *Mycobacterium tuberculosis*. - A positive TST reflects **tuberculosis infection**, whether latent or active, making it a valuable tool for assessing prevalence in a community. *Mass miniature radiography* - This method, now largely replaced by digital radiography, primarily detects **active pulmonary tuberculosis** by identifying lung lesions like infiltrates or cavities. - It is less effective for detecting **latent tuberculosis infection (LTBI)**, which represents the majority of infected individuals in a community. *Sputum examination of AFB* - This test is crucial for diagnosing **active pulmonary tuberculosis** by identifying acid-fast bacilli (AFB) in sputum. - However, it only detects individuals who are actively shedding bacteria and may not capture the broader prevalence of **latent infection** in a community. *Clinical examination* - A clinical examination primarily identifies individuals with **symptoms of active tuberculosis**, such as persistent cough, fever, or weight loss. - It is not a reliable method for assessing the overall **prevalence of tuberculosis infection**, particularly asymptomatic latent cases, in a community.

Q: In a normal curve, the area between one standard deviation on either side of the mean will include:

Approximately 68% of the values. ***Approximately 68% of the values*** - In a **normal distribution** (bell curve), approximately **68% of data points** fall within one standard deviation ($\pm1\sigma$) from the mean. - This is a fundamental property of the **empirical rule** (or 68-95-99.7 rule) in statistics. *70 – 85% of the values* - This range is too broad and does not accurately reflect the specific percentage for **one standard deviation**. - While it overlaps with the correct value, it is not the precise percentage associated with $\pm1\sigma$. *95% of the values* - This percentage refers to the data included within **two standard deviations** ($\pm2\sigma$) from the mean in a normal distribution, not one. - The **empirical rule** states that approximately 95% of data falls within two standard deviations. *Less than 50% of the values* - This is incorrect, as the range of **one standard deviation** on either side of the mean covers more than half of the data. - The mean itself divides the data into two 50% halves, so incorporating any deviation around it will cover more than 50%.

Q: Match List-I with List-II and select the correct answer using the code given below the Lists:

A→3 B→4 C→2 D→1. ***Correct Answer: A→3, B→4, C→2, D→1*** **Understanding Health Education Methods:** **A. Symposium → 3. Series of speeches** - A symposium is a formal meeting where multiple experts deliver **sequential speeches** on different aspects of a selected subject - Each speaker presents their perspective, typically without much interaction between speakers during the presentation **B. Panel Discussion → 4. Discussion among the speakers** - A panel involves **interactive discussion among panelists** (experts) on a particular topic - Characterized by dialogue and exchange of views between speakers, often followed by audience questions **C. Workshop → 2. Arriving at a plan of action** - A workshop is a **participatory, problem-solving session** designed to achieve practical outcomes - Participants actively engage in exercises and activities to develop concrete action plans or solutions **D. Role-play → 1. Dramatizing a situation** - Role-play involves **acting out scenarios** to experience different perspectives - Participants assume roles and dramatize situations to understand behaviors, emotions, and decision-making processes *Key Differentiation:* - Symposium = One-way presentations (speakers → audience) - Panel = Two-way discussion (speakers ↔ speakers) - Workshop = Participatory action planning - Role-play = Experiential learning through dramatization

Q: Which of the following insecticides is not used as a larvicide?

Fenthion. ***Fenthion*** - **Fenthion** is an **organophosphate insecticide** primarily used as an **adulticide** for **mosquitoes** and other flying insects. - While it can target adult mosquitoes, it is **not commonly used or recommended as a larvicide** due to its higher toxicity profile and environmental concerns compared to other dedicated larvicides. *Dichlorvos* - **Dichlorvos** (DDVP) is an organophosphate insecticide that has been used as a **larvicide**, particularly in situations where rapid knockdown of larvae is required. - It is known for its **quick action** and **fumigant properties**, making it effective against early mosquito stages. *Paris green* - **Paris green** (copper(II) acetoarsenite) is historically one of the **earliest larvicides** used to control mosquito larvae. - It acts as a **stomach poison** when ingested by mosquito larvae. *Abate* - **Abate** (temephos) is a widely used **organophosphate larvicide** known for its **low toxicity to mammals** and aquatic organisms at recommended doses. - It is effective against mosquito larvae in various breeding sites, including drinking water, making it a **preferred choice for public health programs**.

Q: An outbreak of Viral Hepatitis was reported from a town between June and August of a particular year. 60% of cases occurred in July. Exposure of the community to infection is from:

A single source for a short period. ***A single source for a short period*** - This describes a **point source outbreak**, the classic pattern seen in this scenario - **60% of cases in July** indicates exposure occurred over a **brief period** (likely days to weeks before July) - The 3-month span (June-August) represents the **distribution of cases around the incubation period** of viral hepatitis (typically 2-6 weeks for Hepatitis A) - Common examples: **contaminated water supply**, food at a community gathering, or other single exposure event - This is the **textbook presentation** of a point source epidemic with a characteristic sharp peak *Multiple sources for a short period* - This would produce **multiple peaks** or an irregular epidemic curve, not a single peak in July - Multiple sources would not create the concentrated 60% clustering observed - The pattern described is too uniform for multiple independent sources *A common single source for prolonged periods* - This describes a **continuous common source outbreak** with an extended epidemic curve - Cases would be **distributed more evenly** across June-August without a sharp peak - Example: ongoing contamination of a water supply over months - The 60% concentration in July rules out this pattern *Multiple sources over prolonged periods* - This would result in **endemic disease** or a very flat, prolonged epidemic curve - No sharp peak would be observed - The temporal clustering contradicts this pattern

Q: Severity of a disease is measured by:

Case fatality rate. ***Case fatality rate*** - The **case fatality rate (CFR)** directly measures the **severity** of a disease by indicating the proportion of individuals diagnosed with a disease who ultimately die from it. - A higher CFR implies a more lethal or severe disease. *Incidence rate* - The **incidence rate** measures the **frequency of new cases** of a disease in a population over a specified period. - It reflects how quickly a disease is spreading, not its severity. *Attributable risk* - **Attributable risk (AR)** quantifies the proportion of disease incidence in an exposed group that can be attributed to the exposure. - It measures the **public health impact** of an exposure, not the inherent severity of the disease itself. *Relative risk* - **Relative risk (RR)** compares the probability of an event (e.g., disease development) in an **exposed group** to the probability of the event in an **unexposed group**. - It indicates the **strength of association** between an exposure and a disease, not the severity of the disease in affected individuals.

Question 1

Excessive nitrates in drinking water can produce:

Accepted Answer

Methaemoglobinaemia

Answer

Polycythemia vera

Answer

Hypochromic microcytic anemia

Answer

Hemophilia

Question 2

The following statements are correct for healthful school environment except:

Accepted Answer

In the classroom, desks should be of minus type.

Answer

Combined window and door area should be 25% of the floor space.

Answer

Per capita space for each student should be 6 sq. feet.

Answer

One urinal should be provided for 60 students.

Question 3

The following are the indicators for assessing the sensitivity of surveillance of polio except:

Accepted Answer

A minimum of one case of AFP per 100,000 children under 5 years of age detected per year

Answer

At least 80% of the reporting sites should report each month even in the absence of cases

Answer

A minimum of one case of AFP per 100,000 children under 15 years of age detected per year

Answer

Percentage of AFP cases with 2 stools taken within 2 weeks after paralysis onset

Question 4

What is the most important test to assess the prevalence of tuberculosis infection in a community?

Accepted Answer

Tuberculin test

Answer

Mass miniature radiography

Answer

Sputum examination of AFB

Answer

Clinical examination

Question 5

In a normal curve, the area between one standard deviation on either side of the mean will include:

Accepted Answer

Approximately 68% of the values

Answer

70 – 85% of the values

Answer

95% of the values

Answer

Less than 50% of the values

Question 6

Match List-I with List-II and select the correct answer using the code given below the Lists:

Accepted Answer

A→3  B→4  C→2  D→1

Answer

A→1  B→2  C→4  D→3

Answer

A→3  B→2  C→4  D→1

Answer

A→1  B→4  C→2  D→3

Question 7

Which of the following insecticides is not used as a larvicide?

Accepted Answer

Fenthion

Answer

Dichlorvos

Answer

Paris green

Answer

Abate

Question 8

An outbreak of Viral Hepatitis was reported from a town between June and August of a particular year. 60% of cases occurred in July. Exposure of the community to infection is from:

Accepted Answer

A single source for a short period

Answer

Multiple sources over prolonged periods

Answer

Multiple sources for a short period

Answer

A common single source for prolonged periods

Question 9

Which one of the following indicators is not included in Millennium Development Goals?

Accepted Answer

T.B. death rate per 100,000 children (0 – 4 years of age)

Answer

Maternal mortality ratio

Answer

Suicide rate per 100,000 population

Answer

Under five mortality rate

Question 10

Severity of a disease is measured by:

Accepted Answer

Case fatality rate

Answer

Incidence rate

Answer

Attributable risk

Answer

Relative risk

UPSC-CMS 2014 — Community Medicine