UPSC-CMS 2021 - Community Medicine Practice Questions

Q: A new test was developed for detection of COVID-19. What is the sensitivity of the test as per the information provided above?

37.5%. ***37.5%*** - **Sensitivity** is calculated as the number of **true positives** divided by the sum of true positives and false negatives (i.e., total number of individuals with the disease). - From the table, **True Positives (Test Positive and Disease +)** = 60, and **False Negatives (Test Negative and Disease +)** = 100. So, sensitivity = 60 / (60 + 100) = 60 / 160 = 0.375 or 37.5%. *97%* - This value is incorrect. It might be confused with **Negative Predictive Value (NPV)**, which is the probability that subjects with a negative test truly don't have the disease (1800/1900 ≈ 0.947 or 94.7%), but it's not 97%. - It does not correctly represent the calculation for sensitivity as described above. *20.5%* - This value is incorrect. It does not correspond to any standard epidemiological measure of test performance based on the provided data. - This percentage might arise from an incorrect division or addition of values from the table. *60%* - This value is incorrect. While 60 **true positives** are present, sensitivity requires dividing this by the total number of diseased individuals, not just any other total. - This could be confused with the ratio of true positives to total positive tests (Positive Predictive Value), which would be 60/100, resulting in 60%, but this is not sensitivity.

Q: A study was conducted to evaluate the effectiveness of a new antidiabetic drug. The fasting blood glucose levels (mg/dL) of 5 diabetic patients after 3 months of treatment were: 110, 94, 102, 98, 96. Consider the following statements about this data: 1. The range of blood glucose levels is 16 mg/dL 2. The median blood glucose level is 98 mg/dL 3. The standard deviation is √10 mg/dL

1 and 2 only. ***1 and 2 only*** - **Statement 1 is correct**: The **range** is calculated as maximum value minus minimum value. Ordering the data: 94, 96, 98, 102, 110 mg/dL. Range = 110 - 94 = **16 mg/dL** ✓ - **Statement 2 is correct**: For the ordered dataset (94, 96, 98, 102, 110), with n=5 observations, the **median** is the middle (3rd) value = **98 mg/dL** ✓ - **Statement 3 is incorrect**: To calculate standard deviation: - Mean (x̄) = (110 + 94 + 102 + 98 + 96) / 5 = **100 mg/dL** - Deviations from mean: 10, -6, 2, -2, -4 - Sum of squared deviations: 100 + 36 + 4 + 4 + 16 = **160** - Sample variance = 160 / (n-1) = 160 / 4 = **40** - Standard deviation = √40 = **2√10 ≈ 6.32 mg/dL** (NOT √10 ≈ 3.16 mg/dL) ✗ *1, 2 and 3* - This would only be correct if all three statements were true. However, **statement 3 is incorrect** as the actual standard deviation is √40 (or 2√10), not √10. *1 and 3 only* - This is incorrect because **statement 3 is false** (SD = √40, not √10), while statement 2 is actually correct. *2 and 3 only* - This is incorrect because **statement 1 is correct** (range is indeed 16 mg/dL) and **statement 3 is incorrect** (SD ≠ √10).

Q: Which of the following are correct in respect of Diphtheria? 1. The incubation period is 14 to 28 days 2. Diphtheria antitoxin is used in treatment of cases 3. It is one of the diseases protected from, by the Pentavalent vaccine given in National Program

2 and 3 only. **Correct Answer: Option B (2 and 3 only)** **Analysis of Statements:** **Statement 1: INCORRECT** - The incubation period for diphtheria is **2 to 5 days** (range: 1-10 days), NOT 14 to 28 days - The stated period of 14-28 days is inaccurate **Statement 2: CORRECT** - **Diphtheria antitoxin (DAT)** is the mainstay of treatment - It neutralizes the exotoxin produced by *Corynebacterium diphtheriae* - Must be given early to prevent irreversible toxin-mediated tissue damage **Statement 3: CORRECT** - **Pentavalent vaccine** (DPT-HepB-Hib) is given under India's Universal Immunization Programme - Protects against 5 diseases: Diphtheria, Pertussis, Tetanus, Hepatitis B, and *Haemophilus influenzae* type b - Contains diphtheria toxoid for active immunization **Why Other Options are Incorrect:** *Option A (1, 2 and 3)* - Incorrect because Statement 1 has wrong incubation period *Option C (1 and 3 only)* - Incorrect because Statement 1 has wrong incubation period - Also omits the important fact about antitoxin treatment *Option D (1 and 2 only)* - Incorrect because Statement 1 has wrong incubation period - Also omits the important fact about Pentavalent vaccine protection

Q: A person has presented with history of dog-bite on the uncovered surface of his right leg. There is a minor abrasion without bleeding. Consider the following statements about management : 1. The bite should be taken as a category I contact with suspect animal 2. The bite requires local treatment of the wound 3. The person requires immediate vaccination 4. The person requires immediate administration of rabies immunoglobulin Which of the above statements are correct ?

2 and 3 only. ***2 and 3 only*** - A minor abrasion without bleeding falls under **Category II exposure** per WHO guidelines, requiring **local wound treatment** and **immediate vaccination**. - **Category II exposures** are defined as nibbling of uncovered skin, minor abrasions without bleeding, or scratches without bleeding. *1 and 2* - The bite described (minor abrasion without bleeding) is classified as **Category II exposure** by WHO, not Category I. - **Category I contact** involves touching or feeding an animal, or licks on intact skin, requiring **no post-exposure prophylaxis** as there is no breach of skin integrity. *2, 3 and 4* - While local wound treatment and vaccination are correct for Category II exposure, **rabies immunoglobulin (RIG)** is not indicated for Category II. - RIG is reserved for **Category III exposures**, which involve single or multiple transdermal bites or scratches, contamination of mucous membranes with saliva, or licks on broken skin. *3 and 4 only* - Immediate vaccination is correct, but **rabies immunoglobulin** is not necessary for a minor abrasion without bleeding (Category II exposure). - Administration of RIG is only indicated after **Category III exposures** due to the higher risk of rabies transmission.

Q: Consider the following stages of modern sewage treatment plants : 1. Use of Grit chamber 2. Use of Primary sedimentation tank 3. Screening 4. Use of Sludge digester What would be the correct sequence of the above stages ?

3→1→2→4. ***3→1→2→4*** - The correct sequence for modern sewage treatment begins with **screening** (3) to remove large debris, followed by **grit chambers** (1) for sand and gravel, then **primary sedimentation tanks** (2) to settle organic solids. Finally, the collected sludge is processed in a **sludge digester** (4). - This order ensures progressive removal of contaminants, from large physical objects to settled organic matter, optimizing the efficiency of each treatment stage. *2→3→4→1* - This sequence incorrectly places the **primary sedimentation tank** (2) as the first step, which would be inefficient as large debris and grit would interfere with its operation. - It also reverses the order of screening and grit removal, which are crucial initial physical processes. *3→2→1→4* - While starting with **screening** (3) is correct, this sequence incorrectly places the **primary sedimentation tank** (2) before the **grit chamber** (1). - Grit removal should precede primary sedimentation to prevent abrasive materials from damaging equipment and accumulating in sedimentation tanks. *4→2→1→3* - This sequence is entirely incorrect, as it begins with the **sludge digester** (4), which is a final step in sludge processing, not the initial treatment of raw sewage. - It also drastically misorders the preliminary physical treatment stages.

Q: A vital layer, also known as "Schmutzdecke" is seen in which one of the following ?

Slow sand filter. ***Slow sand filter*** - A vital biological layer known as **"Schmutzdecke"** or **"filter skin"** forms on the surface of slow sand filters. - This layer, composed of **algae, bacteria, fungi**, and protozoa, is crucial for effective water purification by trapping and breaking down organic matter and pathogens. *Air filter* - Air filters primarily remove particulate matter from air, not water, and do not develop a biological layer like **Schmutzdecke**. - Their mechanism involves mechanical filtration, not biological degradation. *Reverse osmosis filter* - Reverse osmosis filters use a **semi-permeable membrane** to remove dissolved solids and contaminants from water under pressure. - They operate on a physical process and do not rely on the formation of a biological "Schmutzdecke" layer for filtration. *Rapid sand filter* - Rapid sand filters primarily rely on **physical straining** and **coagulation/flocculation** for clarification, followed by backwashing to clean the filter media. - While some biological activity may occur, they do not form a distinct, vital **"Schmutzdecke"** layer as seen in slow sand filters, and their primary mechanism is different.

Q: The most sensitive indicator of environmental iodine deficiency is

Urinary iodine excretion. ***Urinary iodine excretion*** - **Urinary iodine excretion** reflects recent dietary iodine intake, making it the most sensitive and commonly used indicator for assessing current iodine status in a population. - A median urinary iodine concentration of less than 100 μg/L in a population indicates **iodine deficiency**. *Prevalence of neonatal hypothyroidism* - While reflecting severe iodine deficiency, **neonatal hypothyroidism** occurs later in the deficiency cascade and is not sensitive enough to detect mild to moderate deficiencies early. - It would indicate a long-standing, significant deficiency rather than an early environmental change. *Prevalence of cretinism* - **Cretinism** is a severe and irreversible consequence of prolonged and profound iodine deficiency during critical periods of development (fetal and early infancy). - Its prevalence indicates severe, chronic iodine deficiency and is not a sensitive marker for early or mild environmental iodine deficiency. *Prevalence of goitre* - The **prevalence of goitre** (enlarged thyroid gland) can be used as an indicator of iodine deficiency, but it is less sensitive than urinary iodine excretion. - Goitre develops over a longer period in response to chronic iodine deficiency and may not reflect recent changes in environmental iodine levels.

Q: Which one of the following is a famous large prospective study that helped establish risk factors for coronary heart disease ?

Framingham study. ***Framingham study*** - The **Framingham Heart Study** is a landmark **long-term prospective cohort study** that began in 1948 in Framingham, Massachusetts, to identify common factors or characteristics that contribute to **cardiovascular disease (CVD)**. - This study has been instrumental in identifying major **CVD risk factors** such as high blood pressure, high cholesterol, smoking, obesity, diabetes, and physical inactivity. *Pittsburgh study* - While Pittsburgh is a hub for medical research, there isn't a single "Pittsburgh study" that holds the same widespread recognition for establishing **cardiovascular risk factors** as the Framingham study. - Various studies from Pittsburgh institutions might contribute to cardiovascular research, but none are as globally recognized for this specific contribution. *Adelaide study* - The "Adelaide study" generally refers to research conducted in Adelaide, Australia, which has produced various medical findings. - However, it is not known as a prominent, large-scale prospective study specifically designed to establish widespread **coronary heart disease risk factors** in the same league as the Framingham Heart Study. *Birmingham study* - Many medical studies are conducted in Birmingham (both in the UK and USA), but there isn't one definitive "Birmingham study" with the historical significance and impact on identifying **coronary heart disease risk factors** that the Framingham study has. - Research from Birmingham typically contributes to various medical fields, but not specifically as the primary source for these fundamental risk factor discoveries.

Q: Of the following international agencies, which agency has been assisting India in development of friendly models of sanitation ?

SIDA (Swedish International Development Agency). ***SIDA (Swedish International Development Agency)*** - **SIDA** has been a major development partner with India in the **water and sanitation sector** - Provided significant support for developing **community-friendly sanitation models**, including community-led total sanitation (CLTS) approaches - Their assistance included **technical expertise, financial aid, and capacity building** for sustainable sanitation infrastructure *CARE (Cooperative for Assistance and Relief Everywhere)* - **CARE** is a major international humanitarian organization focused primarily on **food security, health, and emergency relief** - While involved in community development, not specifically known for developing sanitation models in India *DANIDA (Danish Development Agency)* - **DANIDA's** major engagements in India have focused on **renewable energy, environmental protection, and poverty reduction** - While supporting general water and sanitation projects, not the leading agency for developing specific sanitation models in India *Ford Foundation* - A philanthropic organization focused on **social justice, education, and civil society building** - In India, primarily supports **NGOs and policy reforms** rather than direct development of sanitation infrastructure

Q: Which one among the following was used for measuring economic status of households, in the National Family Health Survey-III (NFHS-III) ?

Wealth index. ***Wealth index*** - The **National Family Health Survey-III (NFHS-III)** used a **wealth index** as a primary measure to assess the economic status of households. - This index is a composite measure derived from household assets and housing characteristics. *Lifestyle index* - The term "lifestyle index" is a general concept and was not the specific, officially recognized tool for measuring economic status in NFHS-III. - While lifestyle aspects can be indicators of economic status, they are typically integrated into broader indices like the wealth index rather than being a standalone measure in this context. *Pareek scale* - The **Pareek scale** was not used in NFHS-III for measuring household economic status. - The Pareek scale is a socio-economic status scale that primarily focuses on **occupational prestige** and education, and it is less commonly used for national health surveys in India compared to asset-based indices. *Kuppuswamy's scale* - **Kuppuswamy's Socioeconomic Status Scale** was not used in the NFHS-III survey. - This scale is an older and more commonly used tool in clinical and research settings within India, but it primarily classifies families based on **education** and **occupation** of the head of the family, and family income.

Question 1

A new test was developed for detection of COVID-19. What is the sensitivity of the test as per the information provided above?

Accepted Answer

37.5%

Answer

97%

Answer

20.5%

Answer

60%

Question 2

A study was conducted to evaluate the effectiveness of a new antidiabetic drug. The fasting blood glucose levels (mg/dL) of 5 diabetic patients after 3 months of treatment were: 110, 94, 102, 98, 96.

Consider the following statements about this data:

1. The range of blood glucose levels is 16 mg/dL
2. The median blood glucose level is 98 mg/dL  
3. The standard deviation is √10 mg/dL

Accepted Answer

1 and 2 only

Answer

1, 2 and 3

Answer

1 and 3 only

Answer

2 and 3 only

Question 3

Which of the following are correct in respect of Diphtheria?

1. The incubation period is 14 to 28 days
2. Diphtheria antitoxin is used in treatment of cases
3. It is one of the diseases protected from, by the Pentavalent vaccine given in National Program

Accepted Answer

2 and 3 only

Answer

1, 2 and 3

Answer

1 and 3 only

Answer

1 and 2 only

Question 4

A person has presented with history of dog-bite on the uncovered surface of his right leg. There is a minor abrasion without bleeding. Consider the following statements about management :

1. The bite should be taken as a category I contact with suspect animal
2. The bite requires local treatment of the wound
3. The person requires immediate vaccination
4. The person requires immediate administration of rabies immunoglobulin Which of the above statements are correct ?

Accepted Answer

2 and 3 only

Answer

1 and 2

Answer

2, 3 and 4

Answer

3 and 4 only

Question 5

Consider the following stages of modern sewage treatment plants :

1. Use of Grit chamber
2. Use of Primary sedimentation tank
3. Screening
4. Use of Sludge digester
What would be the correct sequence of the above stages ?

Accepted Answer

3→1→2→4

Answer

2→3→4→1

Answer

3→2→1→4

Answer

4→2→1→3

Question 6

A vital layer, also known as "Schmutzdecke" is seen in which one of the following ?

Accepted Answer

Slow sand filter

Answer

Air filter

Answer

Reverse osmosis filter

Answer

Rapid sand filter

Question 7

The most sensitive indicator of environmental iodine deficiency is

Accepted Answer

Urinary iodine excretion

Answer

Prevalence of neonatal hypothyroidism

Answer

Prevalence of cretinism

Answer

Prevalence of goitre

Question 8

Which one of the following is a famous large prospective study that helped establish risk factors for coronary heart disease ?

Accepted Answer

Framingham study

Answer

Pittsburgh study

Answer

Adelaide study

Answer

Birmingham study

Question 9

Of the following international agencies, which agency has been assisting India in development of friendly models of sanitation ?

Accepted Answer

SIDA (Swedish International Development Agency)

Answer

CARE (Cooperative for Assistance and Relief Everywhere)

Answer

DANIDA (Danish Development Agency)

Answer

Ford Foundation

Question 10

Which one among the following was used for measuring economic status of households, in the National Family Health Survey-III (NFHS-III) ?

Accepted Answer

Wealth index

Answer

Lifestyle index

Answer

Pareek scale

Answer

Kuppuswamy’s scale

UPSC-CMS 2021 — Community Medicine