Antiserum is available for passive immunization against ?
Which of the following statements best describes the operational definition of onchocerciasis elimination?
Transovarian transmission is seen in-
What is the primary method of primordial prevention for Coronary Artery Disease (CAD)?
Which grain has the highest calcium content?
Which of the following is a key criterion for a prudent diet?
In rural areas, what is the recommended distance for cattle sheds to be placed away from houses?
What is a standard requirement for the design of a slaughterhouse?
What is a psychrometer used to measure?
Which of the following statements about slow sand filters is true?
NEET-PG 2013 - Community Medicine NEET-PG Practice Questions and MCQs
Question 51: Antiserum is available for passive immunization against ?
- A. Rabies (Correct Answer)
- B. Typhoid
- C. Mumps
- D. Measles
Explanation: ***Rabies*** - **Antiserum** (or rabies immune globulin, RIG) provides immediate **passive immunity** against rabies, neutralizing the virus before the body can mount an active immune response. - It is administered in conjunction with the **rabies vaccine** for post-exposure prophylaxis, especially in severe exposures. *Typhoid* - **Typhoid fever** is primarily prevented through vaccination (active immunization) and improved sanitation. - There is no routinely available antiserum for **passive immunization** against *Salmonella typhi* infection. *Measles* - **Measles** is prevented through active immunization with the MMR (measles, mumps, rubella) vaccine. - While immune globulin can be used for passive protection in exposed, immunocompromised individuals, it's not commonly referred to as "antiserum" in the same context as rabies. *Mumps* - **Mumps** is prevented by active immunization with the MMR vaccine. - Similar to measles, there is no commonly used specific antiserum for **passive immunity** against mumps in the clinical setting.
Question 52: Which of the following statements best describes the operational definition of onchocerciasis elimination?
- A. All interventions have been successfully implemented.
- B. There is no recrudescence of the disease after a defined period.
- C. All of the options are true.
- D. Transmission of O. volvulus has been reduced to a level where it cannot sustain itself in the population. (Correct Answer)
Explanation: **Transmission of O. volvulus has been reduced to a level where it cannot sustain itself in the population.** - This statement accurately reflects the definition of **disease elimination**, where the incidence of infection is reduced to zero in a defined geographical area, signifying that the **transmission cycle can no longer be sustained**. - For onchocerciasis, this means the **vector (blackfly)** is no longer transmitting the parasite (*Onchocerca volvulus*) between humans at a rate that allows the disease to persist. *All interventions have been successfully implemented.* - While successful implementation of interventions is crucial for elimination, it is a **process goal**, not the **ultimate outcome** or operational definition of elimination itself. - Elimination is defined by the **absence of sustained transmission**, which is a direct measure of disease burden, not intervention fidelity. *There is no recrudescence of the disease after a defined period.* - The **absence of recrudescence** (re-emergence) after a defined period is an important indicator of successful elimination validation, but it is a **consequence** or **part of the verification process**, not the primary operational definition. - The operational definition focuses on the **state of transmission** that leads to this sustained absence. *All of the options are true.* - This option is incorrect because only one of the provided statements accurately describes the **operational definition of elimination** in the context of parasitic diseases like onchocerciasis. - The other options describe aspects related to the elimination process or its verification, but not the core definition.
Question 53: Transovarian transmission is seen in-
- A. Malaria
- B. Filaria
- C. Rickettsial diseases (Correct Answer)
- D. None of the options
Explanation: ***Rickettsial diseases*** - **Transovarian transmission** is a key mechanism for the maintenance and spread of **rickettsiae** in arthropod vectors. The bacteria can pass from an infected female arthropod (like a tick or mite) to her offspring via the eggs. - This ensures that the next generation of vectors is already infected and can transmit the disease, even without needing to acquire the pathogen from an infected vertebrate host. *Malaria* - Malaria is transmitted via the bite of an infected **Anopheles mosquito**, which acquires parasites from an infected human. - **Transovarian transmission** does not occur in malaria; mosquitoes are not born with the ability to transmit the parasite. *Filaria* - Filariasis is spread by various **mosquito vectors** (e.g., *Culex*, *Anopheles*, *Aedes*) or **black flies**, which acquire microfilariae from an infected host during a blood meal. - The parasite undergoes development within the insect, but **transovarian transmission** to the insect's offspring does not occur. *None of the options* - This option is incorrect because **rickettsial diseases** do exhibit transovarian transmission, making it a valid answer. - The phenomenon of passing pathogens directly from a female parent to her offspring via the egg is a specific mechanism seen in certain vector-borne diseases.
Question 54: What is the primary method of primordial prevention for Coronary Artery Disease (CAD)?
- A. Lifestyle change (Correct Answer)
- B. Coronary bypass
- C. Treatment of CAD
- D. Screening for hypertension
Explanation: ***Lifestyle change*** - **Primordial prevention** aims to prevent the development of risk factors themselves, which is best achieved through promoting healthy behaviors like diet, exercise, and avoiding tobacco at the population level. - This approach acts *before* the onset of risk factors, addressing societal and environmental determinants of health. - Examples include promoting healthy eating habits in schools, creating walkable communities, and tobacco-free environments. *Coronary bypass* - **Coronary bypass surgery** is a treatment for established CAD with significant blockages, not a preventive measure. - It falls under the category of **tertiary prevention**, aiming to reduce complications and improve quality of life in existing disease. *Treatment of CAD* - **Treating CAD** (e.g., medications like statins or antiplatelets, procedures like angioplasty) is a form of **secondary** or **tertiary prevention**. - It focuses on managing existing disease or preventing its progression, rather than preventing the initial development of risk factors. *Screening for hypertension* - **Screening** is a form of **secondary prevention** aimed at early detection of risk factors or disease. - While important, it occurs *after* risk factors have already developed, unlike primordial prevention which prevents risk factors from emerging.
Question 55: Which grain has the highest calcium content?
- A. Jowar
- B. Bajara
- C. Finger millet (Correct Answer)
- D. None of the options
Explanation: ***Finger millet*** - **Finger millet**, also known as **Ragi**, is exceptionally rich in **calcium**, containing significantly more than other common grains. - It is a valuable dietary source for **bone health** and preventing **calcium deficiencies**. *Jowar* - **Jowar** (sorghum) is a good source of various nutrients but has a **lower calcium content** compared to finger millet. - It is known more for its **fiber** and iron content. *Bajara* - **Bajara** (pearl millet) provides a moderate amount of **calcium** but is surpassed by finger millet. - It is favored for its **energy content** and beneficial fatty acids. *None of the options* - This option is incorrect because **finger millet** indeed has a remarkably high calcium content, making it a clear answer. - The other grains mentioned, while nutritious, do not match finger millet's calcium profile.
Question 56: Which of the following is a key criterion for a prudent diet?
- A. Fat intake 35-40% of total energy
- B. Dietary cholesterol < 300 mg/1000Kcal per day
- C. Salt intake <10 g/day
- D. Saturated fats < 10% of total energy (Correct Answer)
Explanation: ***Saturated fats < 10% of total energy*** - Limiting **saturated fat intake** to less than 10% of total energy is a key recommendation for a prudent diet to reduce the risk of **cardiovascular disease**. - High intake of saturated fats can increase **LDL cholesterol** ("bad" cholesterol), contributing to **atherosclerosis**. *Fat intake 35-40% of total energy* - This range is generally considered **too high** for a healthy diet, as excessive fat intake can lead to **obesity** and increased risk of chronic diseases. - A more prudent range for total fat intake is typically around **20-35% of total energy**. *Dietary cholesterol < 300 mg/1000Kcal per day* - While limiting dietary cholesterol was historically a key recommendation, current guidelines emphasize reducing **saturated and trans fats** more strongly than dietary cholesterol itself due to its limited impact on blood cholesterol for most people. - The limit of **300 mg/day** for dietary cholesterol is an older guideline; many newer recommendations do not specify an upper limit for dietary cholesterol for healthy individuals. *Salt intake <10 g/day* - This statement indicates a salt intake of less than 10 grams per day, which is still **higher** than the generally recommended upper limit for a prudent diet. - Current guidelines suggest limiting **sodium intake** to less than 2300 mg (approximately 5.8g of salt) per day, with an ideal limit of less than 1500 mg (approximately 3.8g of salt) for most adults to manage **blood pressure**.
Question 57: In rural areas, what is the recommended distance for cattle sheds to be placed away from houses?
- A. 5 feet
- B. 10 feet
- C. 20 feet
- D. 25 feet (Correct Answer)
Explanation: ***25 feet*** - A minimum distance of **25 feet (approximately 7.6 meters)** is recommended between cattle sheds and houses in rural areas. - This distance helps to mitigate **odors, flies, dust, and noise**, contributing to better hygiene and living conditions. *5 feet* - A distance of **5 feet** is generally considered too close and would not effectively prevent the transmission of **odors, pests, and potential pathogens** from cattle sheds to houses. - This proximity increases the risk of **nuisance and health hazards** to residents. *10 feet* - While better than 5 feet, a distance of **10 feet** may still be insufficient to adequately separate cattle sheds from houses to prevent issues like **strong odors and fly infestations**. - This proximity could still lead to **sanitation and comfort concerns** for residents. *20 feet* - A distance of **20 feet** offers a reasonable buffer; however, **25 feet** is the more commonly recommended minimum to ensure a greater margin of safety and comfort. - While 20 feet is better for ventilation and pest control than smaller distances, it might still allow some impact on **residential air quality**.
Question 58: What is a standard requirement for the design of a slaughterhouse?
- A. Adequate ventilation systems must be installed.
- B. Floors and walls must be made of washable, non-absorbent materials.
- C. Separate areas for clean and dirty operations must be maintained.
- D. All of the above are standard requirements. (Correct Answer)
Explanation: ***All of the above are standard requirements.*** - Proper design and construction of a slaughterhouse are crucial for maintaining **hygiene**, preventing **contamination**, and ensuring **food safety**. - All three requirements work together to create a safe environment for meat processing and prevent the spread of pathogens. - These standards are mandated by public health regulations and food safety guidelines. **Why each requirement is essential:** **Adequate ventilation systems must be installed:** - Controls **temperature and humidity** in processing areas - Removes airborne contaminants and prevents condensation - Ensures worker comfort and reduces microbial growth - Helps in odor control and maintaining air quality **Floors and walls must be made of washable, non-absorbent materials:** - Enables **easy cleaning and sanitation** to prevent microbial growth - Non-absorbent surfaces (like tiles, stainless steel) prevent **contamination absorption** - Facilitates effective disinfection procedures - Prevents harboring of pathogens in porous materials **Separate areas for clean and dirty operations must be maintained:** - Prevents **cross-contamination** between raw and processed products - Clean areas include deboning, cutting, packaging - Dirty areas include stunning, bleeding, evisceration, hide removal - Physical separation is a fundamental principle of **HACCP** (Hazard Analysis Critical Control Point) systems
Question 59: What is a psychrometer used to measure?
- A. Humidity level (Correct Answer)
- B. Airflow rate
- C. Ambient temperature
- D. Surface temperature
Explanation: ***Humidity level*** - A **psychrometer** measures **humidity**, specifically **relative humidity** and dew point. - It consists of two thermometers: a **dry-bulb** and a **wet-bulb** thermometer, which measure the cooling effect of evaporation. *Airflow rate* - **Airflow rate** is typically measured by devices such as **anemometers** or **flow meters**. - These instruments quantify the velocity or volume of air moving through a system. *Ambient temperature* - While a psychrometer includes dry-bulb thermometers that measure **ambient temperature**, its primary purpose is not just this, but rather to calculate **humidity** using the difference between wet and dry bulb readings. - A standard **thermometer** is a simpler and more direct tool for measuring only ambient temperature. *Surface temperature* - **Surface temperature** is usually measured using **infrared thermometers** or **thermocouples** placed in direct contact with a surface. - A psychrometer is designed to measure atmospheric conditions, not the temperature of a solid surface.
Question 60: Which of the following statements about slow sand filters is true?
- A. Is more expensive than other filters
- B. Requires a longer duration for filtration (Correct Answer)
- C. Uses sand size of 0.4 - 0.7 mm
- D. Occupies less space than other filters
Explanation: ***Requires a longer duration for filtration*** - **Slow sand filters** operate at a much lower filtration rate (0.1–0.4 m/h) compared to rapid sand filters, thus requiring a **longer duration** to process the same volume of water. - This low filtration rate allows for the formation of a biological layer, the **schmutzdecke**, which is responsible for much of the purification. *Is more expensive than other filters* - **Slow sand filters** are generally **less expensive to construct and operate** than rapid sand filters because they do not require extensive chemical coagulation, flocculation, or backwashing equipment. - Their primary cost is often land acquisition due to the **larger footprint** required. *Uses sand size of 0.4 - 0.7 mm* - **Slow sand filters** use **finer (smaller) sand**, typically with an **effective size of 0.15-0.30 mm**, which is smaller than the sand used in rapid sand filters (0.4-0.7 mm). - The smaller sand particle size contributes to the slower filtration rate and enhanced biological treatment. *Occupies less space than other filters* - **Slow sand filters** require **significantly more land area** than rapid sand filters for a given output because of their low filtration rate and large basin size. - This larger footprint can be a limiting factor in areas with high land costs.