Which one of the following terms is an "all-or-none phenomenon" and is best described as termination of all transmission of infection by extermination of the infectious agent?
Q232
"Objectives are set forth for different units and subunits, each of which prepares its own plan of action, usually on a short-term basis." The definition best sums up which one among the following terms?
Q233
In the context of rural healthcare delivery in India, the Panchayati Raj system plays a crucial role in implementing health programs at the grassroots level. Consider the following bodies and their involvement in village-level health initiatives:
I. Gram Sabha - Village health planning and monitoring
II. Gram Panchayat - Implementation of health schemes and sanitation
III. Nyaya Panchayat - Health-related dispute resolution
IV. Panchayat Samiti - Block-level health program coordination
Which of the above bodies are present and actively involved in healthcare delivery at the village level?
Q234
Many patients with unexplained rash and fever were reported from a village close to the Primary Health Centre (PHC). What is the first step in initiating the investigation of such an epidemic?
Q235
John Snow's discovery that cholera is a waterborne disease was the outcome of which type of study?
Q236
A study was conducted to evaluate the diagnostic accuracy of ECG for detecting myocardial infarction. The results are shown in the 2x2 table below:
Myocardial Infarction
Present Absent Total
ECG Positive 45 8,000 8,045
ECG Negative 5 32,000 32,005
Total 50 40,000 40,050
Consider the following statements:
I. Sensitivity is 90%.
II. Specificity is 80%.
Which of the statements given above is/are correct?
Q237
Data obtained from hospital records is not a representative sample of the population. What are the reasons for this ?
I. Mild cases and subclinical cases may be missed.
II. Population served by a hospital usually cannot be defined.
III. Cost of hospital care is not recorded.
IV. Admission policy for cases can vary from hospital to hospital.
Select the correct answer using the code given below :
UPSC-CMS 2025 - Community Medicine UPSC-CMS Practice Questions and MCQs
Question 231: Which one of the following terms is an "all-or-none phenomenon" and is best described as termination of all transmission of infection by extermination of the infectious agent?
A. Disease surveillance
B. Disease elimination
C. Disease eradication (Correct Answer)
D. Disease control
Explanation: ***Disease eradication***
- **Eradication** means the permanent reduction to zero of the worldwide incidence of infection caused by a specific agent as a result of deliberate efforts, with no risk of reintroduction.
- It is an "**all-or-none phenomenon**" because the infectious agent is completely exterminated globally, signifying a definitive end to transmission.
*Disease surveillance*
- **Disease surveillance** is the ongoing systematic collection, analysis, interpretation, and dissemination of health data essential to the planning, implementation, and evaluation of public health practice.
- It does not involve the termination or extermination of an infectious agent but rather monitors its spread and impact.
*Disease elimination*
- **Elimination** refers to the reduction to zero of the incidence of a specified disease in a defined geographical area as a result of deliberate efforts.
- While local transmission is stopped, the infectious agent may still exist elsewhere, meaning there is still a risk of reintroduction.
*Disease control*
- **Disease control** involves ongoing public health efforts to reduce the incidence, prevalence, morbidity, and mortality of an infectious disease to a locally acceptable level.
- It focuses on managing and reducing the burden of disease, not necessarily eradicating the causative agent.
Question 232: "Objectives are set forth for different units and subunits, each of which prepares its own plan of action, usually on a short-term basis." The definition best sums up which one among the following terms?
A. Management by objectives (Correct Answer)
B. Input-Output analysis
C. Personnel management
D. Work sampling
Explanation: ***Management by objectives***
- This definition directly describes **Management by Objectives (MBO)**, where clear objectives are set at various levels, and action plans are developed to achieve them.
- MBO emphasizes a **participative approach** where employees and managers collaborate to set realistic and achievable goals, often on a short-term basis.
*Input-Output analysis*
- **Input-Output analysis** studies the interdependencies within an economy, detailing how the output of one industry serves as input for another.
- It does not focus on goal-setting and planning for different organizational units.
*Personnel management*
- **Personnel management** deals with the administrative aspects of employee relations, such as recruitment, training, compensation, and employee welfare.
- While it involves setting objectives related to human resources, it is not the overarching definition for setting objectives across different units and subunits with associated action plans.
*Work sampling*
- **Work sampling** is a method used to determine the proportion of time spent by workers on different tasks over a period.
- It is a tool for **measuring work activities** and efficiency, not a framework for objective setting and action planning within an organization.
Question 233: In the context of rural healthcare delivery in India, the Panchayati Raj system plays a crucial role in implementing health programs at the grassroots level. Consider the following bodies and their involvement in village-level health initiatives:
I. Gram Sabha - Village health planning and monitoring
II. Gram Panchayat - Implementation of health schemes and sanitation
III. Nyaya Panchayat - Health-related dispute resolution
IV. Panchayat Samiti - Block-level health program coordination
Which of the above bodies are present and actively involved in healthcare delivery at the village level?
A. I, II and III
B. III and IV only
C. II, III and IV
D. I and II only (Correct Answer)
Explanation: ***I and II only***
- The **Gram Sabha** is responsible for **village health planning** and monitoring, ensuring community participation in health initiatives.
- The **Gram Panchayat** undertakes the **implementation of health schemes** and plays a vital role in sanitation and environmental health at the village level.
*I, II and III*
- While I and II are correct, the **Nyaya Panchayat** is primarily involved in **justice delivery and dispute resolution**, not active healthcare delivery.
- Its role in healthcare is indirect, often related to settling disputes arising from health-related issues, rather than direct program implementation.
*III and IV only*
- **Nyaya Panchayat** (III) is not directly involved in healthcare delivery at the village level.
- **Panchayat Samiti** (IV) operates at the **block level**, not the village level, though it coordinates health programs that impact villages.
*II, III and IV*
- The **Nyaya Panchayat** (III) does not have a direct role in healthcare delivery.
- The **Panchayat Samiti** (IV) functions at the **block level**, not the village level.
Question 234: Many patients with unexplained rash and fever were reported from a village close to the Primary Health Centre (PHC). What is the first step in initiating the investigation of such an epidemic?
A. Defining the population at risk
B. Confirm existence of epidemic (Correct Answer)
C. Rapid search for all cases
D. Verification of diagnosis
Explanation: ***Confirm existence of epidemic***
- The initial and crucial step in any epidemiological investigation is to **verify if a true epidemic exists**, which involves comparing current disease incidence with expected levels.
- This step helps to differentiate between a real outbreak and a normal fluctuation in disease occurrence or an artifact of increased reporting.
*Defining the population at risk*
- While important, identifying the **population at risk** comes after confirming an epidemic and is essential for calculating attack rates and understanding disease spread.
- This step helps in understanding who might be exposed or susceptible, allowing for targeted interventions.
*Rapid search for all cases*
- A **rapid search for all cases** is a critical component of case finding once an epidemic has been confirmed and a case definition established.
- This step helps in understanding the magnitude of the outbreak and identifying patterns of transmission.
*Verification of diagnosis*
- **Verification of diagnosis** is crucial for ensuring that reported cases meet the established case definition and to exclude other conditions.
- This process helps to ensure the accuracy of data collected during the investigation and precedes further epidemiological analysis.
Question 235: John Snow's discovery that cholera is a waterborne disease was the outcome of which type of study?
A. Risk factor trial
B. Uncontrolled trial
C. Natural experiment (Correct Answer)
D. Trial of aetiological agent
Explanation: ***Natural experiment***
- John Snow's investigation of the 1854 cholera outbreak in London specifically involved observing the effects of **different water sources** on cholera rates among distinct populations.
- This constituted a **natural experiment** because the exposure (water source) was not manipulated by the researcher but rather occurred naturally within the population.
*Risk factor trial*
- A risk factor trial would involve **deliberately exposing** or changing exposure to a risk factor in different groups to observe outcomes, which is unethical and was not done by Snow.
- This type of study is usually **interventional** and aims to determine causality by actively managing variables.
*Uncontrolled trial*
- An uncontrolled trial typically involves an intervention but without a **comparison group**, making it difficult to attribute observed effects solely to the intervention.
- Snow's study, conversely, involved comparing outcomes between groups (those using different water pumps).
*Trial of aetiological agent*
- A trial of an aetiological agent would involve **intentionally introducing** or removing the suspected disease-causing agent (e.g., cholera bacteria) to observe its effects.
- John Snow did not perform such an interventional study; his work was observational, identifying associations in natural settings.
Question 236: A study was conducted to evaluate the diagnostic accuracy of ECG for detecting myocardial infarction. The results are shown in the 2x2 table below:
Myocardial Infarction
Present Absent Total
ECG Positive 45 8,000 8,045
ECG Negative 5 32,000 32,005
Total 50 40,000 40,050
Consider the following statements:
I. Sensitivity is 90%.
II. Specificity is 80%.
Which of the statements given above is/are correct?
A. Both I and II (Correct Answer)
B. Neither I nor II
C. II only
D. I only
Explanation: **Both I and II**
- **Sensitivity** = True Positives / (True Positives + False Negatives) = 45 / (45 + 5) = 45/50 = **0.90 or 90%** ✓
- **Specificity** = True Negatives / (True Negatives + False Positives) = 32,000 / (32,000 + 8,000) = 32,000/40,000 = **0.80 or 80%** ✓
- Both calculations are correct based on the 2×2 contingency table
- **Sensitivity** measures the ability of the test to correctly identify those with disease (true positive rate)
- **Specificity** measures the ability of the test to correctly identify those without disease (true negative rate)
*I only*
- Incorrect because Statement II (Specificity = 80%) is also correct, not just Statement I
*II only*
- Incorrect because Statement I (Sensitivity = 90%) is also correct, not just Statement II
*Neither I nor II*
- Incorrect because both statements are mathematically correct based on the given data
Question 237: Data obtained from hospital records is not a representative sample of the population. What are the reasons for this ?
I. Mild cases and subclinical cases may be missed.
II. Population served by a hospital usually cannot be defined.
III. Cost of hospital care is not recorded.
IV. Admission policy for cases can vary from hospital to hospital.
Select the correct answer using the code given below :
A. II and III only
B. II, III and IV
C. I and II only
D. I, II and IV (Correct Answer)
Explanation: ***I, II and IV***
- Hospital records tend to miss **mild or subclinical cases** because these individuals may not seek hospital care, leading to an underrepresentation of the true disease prevalence.
- The **population served by a hospital is often ill-defined**, making it difficult to generalize findings to a specific community or broader population.
- **Admission policies vary between hospitals**, meaning the types of cases seen at one institution might differ significantly from another, affecting sample representativeness.
*II and III only*
- While the **population served by a hospital is often ill-defined** (II), the cost of hospital care not being recorded (III) does not directly make the sample unrepresentative of the population's health status or disease prevalence.
- The lack of cost data primarily impacts financial analysis, not the epidemiologic representativeness of patient data.
*II, III and IV*
- The statement that the **population served by a hospital usually cannot be defined** (II) and that **admission policies vary** (IV) are valid reasons for non-representativeness.
- However, the **cost of hospital care not being recorded** (III) is not a direct reason why hospital data would fail to represent disease patterns or demographics of the general population.
*I and II only*
- Missing **mild and subclinical cases** (I) and an **ill-defined target population** (II) are valid reasons for unrepresentative data.
- However, this option omits the crucial point that **hospital admission policies vary** (IV), which significantly influences the types of cases included in hospital records and their generalizability.
Ophthalmology
1 questions
Q231
Of the following ocular manifestations of Vitamin A deficiency, the first sign that can be clinically seen is:
UPSC-CMS 2025 - Ophthalmology UPSC-CMS Practice Questions and MCQs
Question 231: Of the following ocular manifestations of Vitamin A deficiency, the first sign that can be clinically seen is:
A. Bitot's spots
B. Nyctalopia
C. Corneal Xerosis
D. Conjunctival Xerosis (Correct Answer)
Explanation: ***Conjunctival Xerosis***
- This is the **earliest clinical sign** of vitamin A deficiency in the eye, characterized by dryness of the conjunctiva.
- It often progresses from a dull, lusterless appearance to the development of **Bitot's spots**.
*Bitot's spots*
- These are **foamy, triangular patches** of keratinized epithelium on the conjunctiva, usually temporal to the cornea.
- While a prominent sign, they appear **after** the initial dryness of conjunctival xerosis.
*Nyctalopia*
- Also known as **night blindness**, this is a **functional symptom** rather than a visible clinical sign.
- It indicates impaired vision in low light conditions due to dysfunction of the **retinal rods**, which is a consequence of vitamin A deficiency.
*Corneal Xerosis*
- This is a more **advanced stage** of vitamin A deficiency, where the dryness has progressed to affect the cornea.
- It appears **after** conjunctival xerosis and can lead to more severe complications like corneal ulceration and keratomalacia.
Pediatrics
1 questions
Q231
The bony deformity of 'pigeon chest' in children occurs due to deficiency of:
UPSC-CMS 2025 - Pediatrics UPSC-CMS Practice Questions and MCQs
Question 231: The bony deformity of 'pigeon chest' in children occurs due to deficiency of:
A. Vitamin K
B. Vitamin A
C. Vitamin D (Correct Answer)
D. Vitamin E
Explanation: ***Vitamin D***
- A deficiency in **Vitamin D** leads to **rickets** in children, impairing proper bone mineralization.
- This softening of bones can cause skeletal deformities, including **pigeon chest** (pectus carinatum), where the sternum protrudes forward.
*Vitamin K*
- **Vitamin K** is crucial for **blood clotting** by synthesizing coagulation factors.
- Its deficiency primarily leads to bleeding disorders, not skeletal deformities like pigeon chest.
*Vitamin A*
- **Vitamin A** is essential for **vision**, immune function, and cellular growth.
- A deficiency can cause **night blindness** and impaired immunity, but it is not directly linked to bone deformities.
*Vitamin E*
- **Vitamin E** is a powerful **antioxidant** that protects cells from damage.
- While essential for neurological function and immunity, its deficiency does not cause skeletal abnormalities such as pigeon chest.