UGC NTA NET/JRF Exam, Social Medicine & Community Health, June-2025

The presence and development of insect vectors (like lice, mites, ticks, or fleas) on the body. clothing, or mucous membranes is called an infestation.

• Infection refers to the invasion and multiplication of microorganisms (bacteria, viruses, fungi, parasites) within body tissues.

• Infestation refers to external colonization by arthropods.
Example: Head lice on the soap or scabies mites in the skin.

The rule of 70 (or doubling time formula) is used to estimate how many years it takes for a population to double: Doubling Time (years)
= 70/ Annual Growth Rate (%)
For a growth rate between 0.5% and 1.0%:
• At 0.5% → 70/0.5 = 140 years
• At 1.0% 70/1.0 = 70 years
So, the population doubling time range = 70-139 years.

Indirect transmission of diseases occurs when the infectious agent is transmitted through an intermediate vehicle, vector, or fomite.
Examples:

• Vehicle-borne (e.g., food, water, blood)
• Vector-borne (e.g., mosquitoes, fleas)
• Fomite-borne (e.g., clothes, utensils)

However, vertical transmission (mother to child during pregnancy, delivery, or breastfeeding) is a direct mode of transmission, not indirect.

A scatter plot is used to show the relationship (correlation) between two continuous variables. Each point on the plot represents a pair of values (X, Y), allowing visualization of the strength and direction of correlation (positive, negative, or none).

Example: Correlation between height and weight.

According to the Dietary Guidelines for Indians, 2024 (ICMR-NIN), sedentary pregnant women are advised to have at least 15 minutes of direct sunlight exposure daily to maintain adequate Vitamin D levels. This helps in calcium absorption and supports fetal bone development.

Primary prevention is applied during the prepathogenesis phase of the natural history of disease, i.e., before the disease process begins. This stage focuses on health promotion and specific protection to prevent the onset of disease.

Examples include immunization, health education, use of safe water, balanced diet, and lifestyle modification.

For the optimum use of health investment, principles such as administrative streamlining, geographic urgency, and minimizing catastrophic health expenditure help ensure efficiency and equity in health resource utilization.

However, supplierinduced demand is an exception, as it refers to unnecessary medical services or interventions prompted by healthcare providers to increase profits, leading to inefficient use of resources.

As per the Dietary Guidelines for Indians (ICMRNIN, 2024), folate-rich foods include green leafy vegetables, nuts, and legumes, which are vital for cell division and prevention of anemia and neural tube defects.

However, tea is not a source of folate; in fact, excessive tea consumption may interfere with iron absorption.

The yellow fever vaccine (17D strain) is a live attenuated vaccine administered as:

• 0.5 ml,
• Subcutaneously,
• Single dose (provides protection for at least 10 years; in most cases, lifelong).
In India, it is recommended for travelers to endemic countries in Africa and South America.

The Physical Quality of Life Index (PQLI) is a composite measure developed to assess the quality of life of a population based on social indicators rather than economic ones.
It includes three indicators:
1. Life expectancy at age one (not at birth),
2. Infant mortality rate, and
3. Literacy rate.
These indicators collectively reflect the population's health and educational status.