Non-Communicable Diseases Practice Questions

Q: All of the following are modes of transmission of leprosy except?

Blood transfusion. **Explanation:** Leprosy, caused by *Mycobacterium leprae*, is primarily a chronic infectious disease of the skin and peripheral nerves. Understanding its transmission is crucial for NEET-PG. **Why Blood Transfusion is the Correct Answer:** Unlike many other bacterial infections, **blood transfusion** is not a recognized mode of transmission for leprosy. *M. leprae* is an obligate intracellular pathogen that resides primarily within macrophages and Schwann cells. It does not survive well or circulate in the free plasma in concentrations sufficient to cause infection via transfusion. **Analysis of Incorrect Options:** * **Droplet Infection (Option D):** This is the **most common** and primary route of transmission. Bacilli are shed in large numbers from the nasal mucosa of untreated lepromatous patients and enter the susceptible host through the upper respiratory tract. * **Transplacental Spread (Option C):** Vertical transmission from an infected mother to the fetus across the placenta has been documented, though it is relatively rare. * **Breast Milk (Option A):** *M. leprae* has been detected in the breast milk of lactating mothers with lepromatous leprosy, making it a possible, albeit less common, route of transmission. **High-Yield Clinical Pearls for NEET-PG:** * **Incubation Period:** Average 3–5 years (the longest among bacterial infections). * **Portal of Entry:** Respiratory tract (most common) and broken skin. * **Infectivity:** Patients become non-infectious within days of starting Multidrug Therapy (MDT). * **Classification:** Ridley-Jopling (Immunological) vs. WHO (Operational: Paucibacillary vs. Multibacillary). * **First Sign:** Usually a pale (hypopigmented) or reddish patch on the skin with loss of sensation.

Q: Which of the following is most strongly associated with coronary heart disease?

Apolipoproteins. **Explanation:** The correct answer is **Apolipoproteins**. In modern cardiovascular epidemiology, apolipoproteins (specifically the **ApoB/ApoA1 ratio**) are considered the most accurate and strongest predictors of coronary heart disease (CHD) risk, even superior to traditional lipid profiles. 1. **Why Apolipoproteins are correct:** Apolipoproteins are the protein components of lipoproteins. **ApoB** is found on all atherogenic particles (LDL, VLDL, IDL), representing the total number of potentially harmful particles. **ApoA1** is the primary protein of HDL (cardioprotective). The INTERHEART study established that the ApoB/ApoA1 ratio is a more powerful predictor of myocardial infarction than any other lipid parameter because it reflects the balance between cholesterol transport into the arterial wall versus its removal. 2. **Why other options are incorrect:** * **VLDL:** While VLDL contributes to triglyceride transport, it is a less specific predictor of CHD compared to the total atherogenic burden measured by ApoB. * **HDL:** Often called "good cholesterol," a low HDL is a risk factor, but it is a less potent predictor of clinical events than the ratio of atherogenic to anti-atherogenic particles. * **Total Lipoproteins:** This is a broad category. Total cholesterol levels can be misleading if a patient has high HDL, making it a weaker predictor than specific apolipoprotein markers. **High-Yield Clinical Pearls for NEET-PG:** * **INTERHEART Study:** Identified the ApoB/ApoA1 ratio as the single most important risk factor for MI globally. * **Rule of Thumb:** High ApoB = High Risk; High ApoA1 = Low Risk. * **Metabolic Syndrome:** Characterized by high triglycerides and low HDL, but even here, ApoB remains a more stable marker as it is not affected by fasting status.

Q: A 40-year-old male patient, a smoker with a sedentary lifestyle and truncal obesity, is being evaluated for risk factors associated with coronary heart disease. Which of the following is NOT considered a risk factor?

Drinking hard water. **Explanation:** The correct answer is **D. Drinking hard water**. In epidemiology, risk factors for Coronary Heart Disease (CHD) are categorized into non-modifiable and modifiable factors. Interestingly, several ecological studies have shown an **inverse relationship** between water hardness and cardiovascular mortality. This means that drinking **soft water** is actually associated with a higher risk of CHD, while hard water (rich in magnesium and calcium) may have a protective effect. **Analysis of Options:** * **High blood pressure (A):** This is a major modifiable risk factor. Hypertension increases mechanical stress on arterial walls, leading to endothelial dysfunction and atherosclerosis. * **Gender (B):** This is a non-modifiable risk factor. Men are generally at a higher risk for CHD compared to pre-menopausal women, as estrogen provides a protective effect in females. * **Obesity (C):** Specifically truncal (android) obesity, as mentioned in the clinical vignette, is a significant modifiable risk factor. It is closely linked to metabolic syndrome, insulin resistance, and dyslipidemia. **Clinical Pearls for NEET-PG:** * **Modifiable Risk Factors:** Smoking, hypertension, dyslipidemia (High LDL, Low HDL), diabetes, obesity, and sedentary lifestyle. * **Non-modifiable Risk Factors:** Age, Male gender, and Family history of premature CHD. * **The "Rule of Halves" in Hypertension:** Only half of the cases in the community are diagnosed; of those, only half are treated; and of those, only half are adequately controlled. * **Protective Factors:** High-density lipoprotein (HDL) and physical activity are considered "negative" risk factors.

Q: What is the clinical goal for the prevention of coronary heart disease regarding the ratio of cholesterol to HDL?

3.5. **Explanation:** The **Total Cholesterol to HDL (High-Density Lipoprotein) ratio** is a significant predictor of cardiovascular risk. In preventive cardiology and community medicine, this ratio is used to assess the balance between "bad" cholesterol (pro-atherogenic) and "good" cholesterol (anti-atherogenic). **1. Why 3.5 is the Correct Answer:** According to standard clinical guidelines (including Park’s Textbook of Preventive and Social Medicine), the primary goal for the prevention of Coronary Heart Disease (CHD) is to maintain a **Total Cholesterol/HDL ratio below 3.5**. A ratio lower than 3.5 is associated with a significantly lower risk of plaque formation and myocardial infarction. **2. Analysis of Incorrect Options:** * **Option A (1.5) & B (2.5):** While these ratios are excellent and indicate very low cardiovascular risk, they are not the standard "threshold" or clinical goal defined for the general population in public health guidelines. * **Option D (4.5):** A ratio above 4.5 is considered an indicator of **high risk** for CHD. In clinical practice, a ratio of 5.0 or higher suggests a doubling of cardiovascular risk compared to the ideal. **3. High-Yield Clinical Pearls for NEET-PG:** * **HDL (The "Good" Cholesterol):** It facilitates reverse cholesterol transport. A level ** 150 mg/dL** are considered a component of Metabolic Syndrome. * **Rule of Thumb:** For CHD prevention, the goal is to keep the Total Cholesterol/HDL ratio **< 3.5** and the LDL/HDL ratio **< 3.0**.

Q: What are the primary hosts involved in the natural transmission cycle of the Japanese encephalitis virus?

Pigs and Mosquitoes. ### Explanation **Japanese Encephalitis (JE)** is a zoonotic viral disease caused by a Group B Arbovirus (Flavivirus). The natural transmission cycle involves a complex interplay between reservoirs, amplifiers, and vectors. **1. Why Option A is Correct:** The transmission cycle of JE is primarily **Enzootic**. * **Pigs** act as the **Amplifier Host**. They develop high-level viremia without showing clinical signs, allowing mosquitoes to pick up the virus easily. * **Mosquitoes** (primarily *Culex tritaeniorhynchus*) act as the **Vector**. They transmit the virus from the amplifier host to humans. * **Ardeid birds** (herons, egrets) act as the **Natural Reservoir/Maintenance Host**. **2. Why Other Options are Incorrect:** * **Option B (Cattle and Birds):** While birds are reservoirs, cattle are "dead-end" hosts. They develop antibodies but do not maintain enough viremia to infect mosquitoes. * **Option C (Pigs and Humans):** Humans are **"Dead-end Hosts."** The level and duration of viremia in humans are insufficient to infect a biting mosquito; therefore, humans do not contribute to the transmission cycle. * **Option D (Birds and Pigs):** While both are involved in the cycle, the question asks for the primary hosts involved in *transmission*. The cycle typically alternates between the vector (mosquito) and the host (pig/bird). **High-Yield Clinical Pearls for NEET-PG:** * **Vector:** *Culex tritaeniorhynchus* (breeds in stagnant water/paddy fields; "Outdoor biters"). * **Amplifier Host:** Pig (The "Link" between nature and man). * **Dead-end Hosts:** Humans and Horses. * **Vaccination:** Live attenuated **SA-14-14-2** is the most commonly used vaccine in the National Immunization Schedule (given at 9 months and 16–24 months). * **Sentinel Surveillance:** Done by monitoring pigs to predict an outbreak.

Q: What is the chosen method for the measurement of obesity?

Skinfold thickness. **Explanation:** Obesity is defined as an abnormal or excessive accumulation of fat that poses a risk to health. The measurement of obesity focuses on quantifying body fat content rather than just total body weight. **Why Skinfold Thickness is Correct:** Skinfold thickness is the most widely used clinical method for estimating body fat percentage. It is based on the principle that approximately **50% of total body fat is located subcutaneously**. Measurements are typically taken using **Harpenden calipers** at specific sites (Triceps, Biceps, Subscapular, and Supra-iliac). The triceps skinfold is the most common site used to screen for obesity in population studies. **Analysis of Incorrect Options:** * **Body electrolyte count:** While obesity can influence total body water and electrolyte distribution, it is not a diagnostic or measurement tool for fat mass. * **Height-weight-sex charts:** These were historically used (e.g., Life Insurance Corporation charts) to determine "ideal" weight. However, they are now considered outdated because they do not distinguish between muscle mass and fat mass. * **Basal oxygen consumption:** This measures the Basal Metabolic Rate (BMR). While BMR is related to lean body mass, it is not a direct or practical measure of obesity. **High-Yield Clinical Pearls for NEET-PG:** * **Quetelet’s Index (BMI):** The most common epidemiological tool. Formula: $Weight (kg) / Height (m^2)$. * **Ponderal Index:** $Height (cm) / \sqrt[3]{Weight (kg)}$. * **Waist-Hip Ratio (WHR):** A measure of central (android) obesity. Risk increases if WHR > 0.9 in men or > 0.85 in women. * **Gold Standard:** Underwater weighing (Hydrostatiometry) or DEXA scans are the most accurate research methods, but skinfold thickness remains the "chosen" practical clinical method.

Q: Risk of damage to the fetus by maternal rubella infection is maximum if the mother gets infected during which period of pregnancy?

6-12 weeks. **Explanation:** The risk of congenital malformations following maternal rubella infection is inversely proportional to the gestational age at the time of infection. This is because the **first trimester** is the period of organogenesis, during which the developing fetus is most vulnerable to the virus. * **Why 6-12 weeks is correct:** During the first trimester (specifically the first 12 weeks), the virus can cross the placenta and cause chronic fetal infection, leading to cell death and inhibited cell division. If infection occurs before 11–12 weeks of pregnancy, the risk of **Congenital Rubella Syndrome (CRS)** is as high as 80–90%. The damage is most severe during this window, often resulting in the classic triad of cataracts, cardiac defects, and sensorineural deafness. * **Why B, C, and D are incorrect:** As the pregnancy progresses beyond the first trimester, the risk of major structural malformations decreases significantly. By **20 weeks** and beyond, the organs are fully formed. While infection in the late second or third trimester can still lead to fetal growth restriction or systemic illness, it rarely results in the multi-organ structural defects characteristic of CRS. **High-Yield Clinical Pearls for NEET-PG:** * **Gregg’s Triad:** Cataract (most common eye lesion), PDA (most common cardiac lesion), and Sensorineural deafness (most common overall manifestation). * **Expanded CRS:** Includes "Blueberry muffin" spots (extramedullary hematopoiesis), radiolucent bone lesions (celery stalking), and microcephaly. * **Vaccination:** Rubella vaccine (RA 27/3 strain) is a live-attenuated vaccine. It is contraindicated in pregnancy, and pregnancy should be avoided for **1 month** (formerly 3 months) after vaccination. * **Diagnosis:** Presence of **Rubella-specific IgM** in the newborn is diagnostic of CRS.

Q: Hypertension is associated with all of the following except:

Excess exercise. **Explanation:** Hypertension is a multifactorial condition influenced by genetic, environmental, and lifestyle factors. **Why "Excess Exercise" is the correct answer:** Regular physical activity is a **protective factor**, not a risk factor, for hypertension. Exercise improves cardiovascular efficiency, reduces peripheral vascular resistance, and helps maintain a healthy weight. While acute, strenuous exertion causes a transient rise in systolic blood pressure, chronic "excess" exercise (as seen in athletes) typically leads to lower resting blood pressure and bradycardia. Therefore, it is not associated with the development of clinical hypertension. **Analysis of Incorrect Options:** * **Excess Salt:** High dietary sodium intake (typically >5g/day) leads to water retention and increased peripheral resistance, making it a primary modifiable risk factor for hypertension. * **Phaeochromocytoma:** This is a classic cause of **secondary hypertension**. This catecholamine-secreting tumor of the adrenal medulla causes paroxysmal or sustained hypertension due to excessive release of epinephrine and norepinephrine. * **Obesity:** There is a linear relationship between Body Mass Index (BMI) and blood pressure. Adiposity leads to increased sympathetic activity and activation of the Renin-Angiotensin-Aldosterone System (RAAS). **High-Yield Clinical Pearls for NEET-PG:** * **Rule of Halves:** In hypertension, half the people are unaware of the condition, half of those aware are not on treatment, and half of those treated do not have their BP controlled. * **Tracking Phenomenon:** Blood pressure levels tend to maintain their peer-group rank over time from childhood to adulthood. * **Salt Intake:** WHO recommends less than **5 grams of salt (2 grams of sodium)** per day for adults. * **Most common cause of Secondary Hypertension:** Renal parenchymal disease.

Q: What is the visual acuity used as a cut-off for school screening programs?

6/9. **Explanation:** In community ophthalmology, school vision screening is a vital strategy for the early detection of refractive errors, which is the leading cause of treatable visual impairment in children. **1. Why 6/9 is the Correct Answer:** According to the guidelines under the **National Programme for Control of Blindness (NPCB)** in India, the cut-off for school screening is **6/9**. * **The Logic:** A child who cannot read the 6/9 line on the Snellen’s chart in either eye is considered to have failed the screening. This threshold is chosen because it is sensitive enough to catch early refractive errors (like myopia) and amblyogenic factors, ensuring that children who might struggle with classroom activities (like reading the blackboard) are referred for a formal refraction by an optometrist or ophthalmologist. **2. Analysis of Incorrect Options:** * **6/6 (Option C):** This is considered "perfect" vision. Using this as a cut-off would result in an overwhelming number of false positives and unnecessary referrals, as minor physiological variations often prevent a child from reading the 6/6 line. * **6/12 (Option A) and 6/18 (Option D):** These thresholds are too lenient for a screening program. By the time a child’s vision drops to 6/12 or 6/18, their academic performance and visual development may already be significantly impacted. 6/18 is, however, the threshold used to define "Visual Impairment" in general population surveys. **High-Yield Clinical Pearls for NEET-PG:** * **Target Age Group:** School screening typically targets children aged **10–14 years**, as this is the peak age for the development of school-age myopia. * **WHO Definition of Blindness:** Visual acuity less than **3/60** in the better eye with best possible correction. * **Visual Impairment Definition:** Visual acuity less than **6/18** in the better eye. * **Refractive Error:** It is the most common cause of "Avoidable Blindness" in children.

Question 1

All of the following are modes of transmission of leprosy except?

Accepted Answer

Blood transfusion

Answer

Breast milk

Answer

Transplacental spread

Answer

Droplet infection

Question 2

Which of the following is most strongly associated with coronary heart disease?

Accepted Answer

Apolipoproteins

Answer

VLDL

Answer

HDL

Answer

Total lipoproteins

Question 3

A 40-year-old male patient, a smoker with a sedentary lifestyle and truncal obesity, is being evaluated for risk factors associated with coronary heart disease. Which of the following is NOT considered a risk factor?

Accepted Answer

Drinking hard water

Answer

High blood pressure

Answer

Gender

Answer

Obesity

Question 4

What is the clinical goal for the prevention of coronary heart disease regarding the ratio of cholesterol to HDL?

Accepted Answer

3.5

Answer

1.5

Answer

2.5

Answer

4.5

Question 5

What are the primary hosts involved in the natural transmission cycle of the Japanese encephalitis virus?

Accepted Answer

Pigs and Mosquitoes

Answer

Cattle and Birds

Answer

Pigs and Humans

Answer

Birds and Pigs

Question 6

What is the chosen method for the measurement of obesity?

Accepted Answer

Skinfold thickness

Answer

Body electrolyte count

Answer

Height-weight-sex chart

Answer

Basal oxygen consumption

Question 7

Risk of damage to the fetus by maternal rubella infection is maximum if the mother gets infected during which period of pregnancy?

Accepted Answer

6-12 weeks

Answer

20-24 weeks

Answer

24-28 weeks

Answer

32-36 weeks

Question 8

Hypertension is associated with all of the following except:

Accepted Answer

Excess exercise

Answer

Excess salt

Answer

Phaeochromocytoma

Answer

Obesity

Question 9

What is the visual acuity used as a cut-off for school screening programs?

Accepted Answer

6/9

Answer

6/12

Answer

6/6

Answer

6/18

Question 10

Which of the following is NOT typically associated with food poisoning?

Accepted Answer

Leukocytosis

Answer

Onset with vomiting

Answer

Tenesmus

Answer

High skin surface temperature

Non-Communicable Diseases — MCQs

Non-Communicable Diseases — MCQs

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