Non-Communicable Diseases Practice Questions

Q: Which of the following dietary changes is NOT advocated by the WHO for the prevention of heart diseases?

An increase in complex carbohydrate consumption. **Explanation:** The prevention of Cardiovascular Diseases (CVD) through dietary modification focuses primarily on the quality and quantity of fats and the restriction of refined sugars, rather than a blanket increase in carbohydrates. **Why Option A is the Correct Answer:** While the WHO recommends replacing saturated fats with complex carbohydrates (like whole grains, vegetables, and fruits), it does **not** advocate for an overall *increase* in total carbohydrate consumption. In fact, high carbohydrate intake (especially refined carbs) can lead to obesity and metabolic syndrome. The goal is a **balanced distribution** of macronutrients, not an increase in the carbohydrate load. **Analysis of Other Options:** * **Option B (Fat intake 20-30%):** This is a standard WHO recommendation. Total fat should be limited to less than 30% of total energy intake to prevent unhealthy weight gain and atherosclerosis. * **Option C (Saturated fats <10%):** High saturated fat intake directly correlates with elevated LDL cholesterol. WHO guidelines strictly recommend limiting these to less than 10% of total energy, replacing them with polyunsaturated fatty acids (PUFAs). * **Option D (Cholesterol <100mg/1000 kcal):** This is a specific quantitative guideline for the primary prevention of heart disease to maintain healthy lipid profiles. **High-Yield Clinical Pearls for NEET-PG:** * **Salt Intake:** WHO recommends reducing salt intake to **<5 grams per day** (approx. 1 teaspoon) to reduce blood pressure and risk of stroke. * **Trans-fats:** Should be limited to **less than 1%** of total energy intake. * **Primal Prevention:** Refers to preventing the *emergence* of risk factors (e.g., discouraging children from picking up smoking or sedentary habits). * **Poli-meal:** A concept involving a combination of natural ingredients (almonds, fish, garlic, fruits) that can reduce CVD risk by up to 75%.

Q: Which of the following is true about the epidemiology of malaria?

The mosquito acts as the definitive host.. **Explanation:** In parasitology, the **definitive host** is defined as the host in which the parasite undergoes its **sexual cycle** of reproduction. In the case of Malaria (*Plasmodium* species), the sexual phase (sporogony) occurs within the female *Anopheles* mosquito. Conversely, the asexual phase (schizogony) occurs in humans, making **Man the intermediate host**. **Analysis of Options:** * **Option D (Correct):** As stated above, the mosquito is the definitive host because the fusion of gametes (syngamy) and the formation of the oocyst occur in the mosquito's gut. * **Option A (Incorrect):** The **extrinsic incubation period** (the time taken for the parasite to develop inside the mosquito) is typically **10–21 days**, depending on the species and ambient temperature. It is rarely as low as 0 days. * **Option B (Incorrect):** In India, malaria transmission is seasonal and peaks during and after the **monsoon (July to November)** due to the availability of stagnant water for mosquito breeding. January to June is generally the dry/off-season. * **Option C (Incorrect):** Man is the intermediate host because only asexual reproduction occurs in human hepatocytes and erythrocytes. **High-Yield NEET-PG Pearls:** * **Intrinsic Incubation Period:** The time interval between the bite of an infected mosquito and the onset of clinical symptoms in man (usually 10–14 days for *P. falciparum*). * **Infective Stage:** For humans, it is the **Sporozoite**; for mosquitoes, it is the **Gametocyte**. * **Temperature:** Optimal transmission occurs between **20°C and 30°C**. Transmission ceases if the temperature falls below 16°C or rises above 30°C. * **Humidity:** Relative humidity of **60% or more** is essential for the survival of the mosquito.

Q: Which type of Intrauterine Device (IUD) has the lowest expulsion rate?

Progestasert. **Explanation:** The expulsion rate of an Intrauterine Device (IUD) is primarily influenced by its design, size, and the degree of uterine irritability it induces. **Why Progestasert is correct:** Progestasert is a first-generation hormone-releasing IUD (releasing progesterone). It is clinically recognized for having the **lowest expulsion rate** among the options provided. This is attributed to its specific T-shaped design and the local effect of progesterone, which tends to reduce uterine contractility and irritability compared to inert or copper-containing devices. **Analysis of Incorrect Options:** * **Lippes loop:** As a first-generation non-medicated (inert) IUD, it has the **highest expulsion rate** and highest incidence of side effects like bleeding and pain due to its large size and bulk. * **Levonorgestrel-releasing IUD (Mirena):** While highly effective and having a low expulsion rate (approx. 3–5%), in comparative classical studies cited in standard textbooks (like Park’s PSM), Progestasert is traditionally noted for the lowest expulsion figures. * **Copper T-220:** Medicated IUDs (Second Generation) have lower expulsion rates than inert ones, but the mechanical irritation caused by copper can still trigger uterine contractions leading to higher expulsion compared to progesterone-based systems. **High-Yield Clinical Pearls for NEET-PG:** * **Most common side effect of IUD:** Bleeding (followed by pain). * **Most common cause for IUD removal:** Bleeding. * **Ideal time for IUD insertion:** During menstruation or within 10 days of the beginning of the period. * **Mechanism of Cu-T:** Primarily biochemical changes in the endometrium and impairment of sperm motility (spermicidal). * **Mechanism of Hormone IUDs:** Thickening of cervical mucus and endometrial atrophy.

Q: Which of the following is an absolute contraindication for combined oral contraceptive pills?

Previous history of thromboembolism. **Explanation:** The correct answer is **Previous history of thromboembolism**. Combined Oral Contraceptive Pills (COCPs) contain estrogen, which increases the hepatic synthesis of clotting factors (II, VII, IX, and X) and decreases anticoagulant levels (Antithrombin III). This creates a hypercoagulable state. Therefore, any condition involving active or past venous thromboembolism (VTE), pulmonary embolism, or major surgery with prolonged immobilization is an **absolute contraindication** (WHO Medical Eligibility Criteria Category 4). **Analysis of Incorrect Options:** * **Diabetes Mellitus:** It is generally a relative contraindication. It only becomes an absolute contraindication if there are vascular complications (nephropathy, retinopathy, neuropathy) or if the duration of diabetes is >20 years. * **Migraine:** Migraine *without* aura is a relative contraindication (Category 3). However, Migraine *with* aura at any age is an absolute contraindication due to the significantly increased risk of ischemic stroke. * **Heart Disease:** This is a broad term. While ischemic heart disease or complicated valvular disease are absolute contraindications, mild forms of heart disease are not. **High-Yield Clinical Pearls for NEET-PG:** * **Absolute Contraindications (WHO Category 4):** Smoker >35 years (≥15 cigarettes/day), Hypertension (≥160/100 mmHg), Current Breast Cancer, and Acute Hepatitis/Cirrhosis. * **Cancer Risk:** COCPs *decrease* the risk of Ovarian and Endometrial cancers (protective effect) but slightly *increase* the risk of Breast and Cervical cancers. * **Drug Interaction:** Rifampicin and Antiepileptics (enzyme inducers) decrease the efficacy of COCPs.

Q: Which of the following is a non-modifiable risk factor for hypertension?

Gender. **Explanation:** Risk factors for hypertension are broadly categorized into two groups: **Non-modifiable** (factors that cannot be changed) and **Modifiable** (behavioral or environmental factors that can be intervened upon). **Why Gender is the Correct Answer:** Gender is a biological attribute determined at birth and cannot be altered through lifestyle or medical intervention. In the context of hypertension, males are generally at a higher risk at younger ages. However, post-menopause, the risk in females increases and often equals or exceeds that of males due to the loss of the protective effects of estrogen. Other non-modifiable factors include age, genetics/family history, and ethnicity. **Analysis of Incorrect Options:** * **B. Obesity:** This is a major modifiable risk factor. Weight reduction (maintaining a BMI between 18.5–24.9 kg/m²) is one of the most effective lifestyle interventions to lower blood pressure. * **C. Salt Intake:** High dietary sodium (>5g of NaCl/day) is a modifiable risk factor. Reducing salt intake is a primary preventive strategy in community medicine. * **D. Cultural characteristics:** While "culture" sounds fixed, these are "acquired over time" (e.g., dietary habits, sedentary lifestyle, or tobacco use). Since these are learned behaviors, they are considered modifiable through health education and behavioral change. **High-Yield NEET-PG Pearls:** * **Rule of Halves:** In hypertension, half the people in a community are aware of their status; half of those aware are on treatment; and half of those treated have their BP controlled. * **Most common modifiable risk factor:** Obesity/Sedentary lifestyle. * **Primary Prevention:** Focuses on population-based strategies (e.g., salt reduction) and high-risk strategies (e.g., weight loss). * **Tracking of Blood Pressure:** This phenomenon suggests that children whose BP is in the higher percentiles tend to maintain that position into adulthood.

Q: Which of the following statements is true about endemic typhus?

Is transmitted by the bite of fleas. **Explanation:** **Endemic Typhus** (also known as Murine Typhus) is caused by the bacterium ***Rickettsia typhi***. It is a zoonotic infection primarily maintained in a cycle between rats and fleas. 1. **Why Option B is Correct:** The primary vector for endemic typhus is the **rat flea (*Xenopsylla cheopis*)**. Transmission to humans occurs when flea feces containing the bacteria are rubbed into the bite wound or other abrasions on the skin. This distinguishes it from Epidemic Typhus, which is transmitted by the human body louse. 2. **Why Other Options are Incorrect:** * **Option A:** *Rickettsia rickettsii* is the causative agent of **Rocky Mountain Spotted Fever**, not endemic typhus. * **Option C:** Endemic typhus has a significant mammalian reservoir, primarily **commensal rats** (*Rattus rattus* and *Rattus norvegicus*). * **Option D:** Rickettsiae are **obligate intracellular pathogens**. They cannot be grown on cell-free, chemically defined media; they require living host cells (like yolk sacs of embryonated eggs or cell cultures) for growth. **High-Yield Clinical Pearls for NEET-PG:** * **The "Typhus Group":** Includes Endemic Typhus (*R. typhi*) and Epidemic Typhus (*R. prowazekii*). * **Weil-Felix Reaction:** A heterophile agglutination test used for diagnosis. Endemic Typhus shows a positive reaction with **OX-19**. * **Drug of Choice:** **Doxycycline** is the gold standard treatment for all rickettsial diseases. * **Brill-Zinsser Disease:** This is a recrudescence (relapse) of *Epidemic* typhus years after the primary attack, not endemic typhus.

Q: What is the best method to identify cases of tuberculosis within a community?

Sputum smear examination. **Explanation:** In the context of public health and community medicine, **Sputum Smear Examination** (specifically for Acid-Fast Bacilli via Ziehl-Neelsen staining) remains the gold standard for **case identification** in a community setting. This is because it identifies "infectious cases"—those individuals who are actively shedding the bacteria and are responsible for the continued transmission of tuberculosis within the community. It is cost-effective, rapid, and highly specific for identifying the most contagious patients. **Analysis of Options:** * **A. Chest X-ray:** While highly sensitive, it is not specific for TB. It cannot differentiate between active infection, healed lesions, or other lung pathologies (like pneumonia or malignancy). It is used as a screening tool, not for definitive case identification. * **B. Mantoux Test:** This is a test of "infection," not "active disease." A positive result only indicates that the person has been exposed to *M. tuberculosis* at some point; it does not mean they currently have TB or are infectious. * **D. Sputum Culture:** This is the "absolute gold standard" for diagnosis and is more sensitive than a smear. However, it is **not the best method for community identification** because it takes 2–8 weeks to yield results, requires sophisticated laboratory infrastructure, and is expensive. **NEET-PG High-Yield Pearls:** * **Primary Tool:** Under the National TB Elimination Program (NTEP), **Sputum Smear** is the primary tool for diagnosis, though **NAAT (CBNAAT/Truenat)** is now the preferred initial diagnostic test where available. * **Infectivity:** One "smear-positive" case can infect 10–15 close contacts in a year if left untreated. * **Screening vs. Diagnosis:** In a community survey, Chest X-ray is the best **screening** tool, but Sputum examination is the best **diagnostic** tool.

Question 1

Which of the following dietary changes is NOT advocated by the WHO for the prevention of heart diseases?

Accepted Answer

An increase in complex carbohydrate consumption

Answer

Reduction in fat intake to 20-30 percent of caloric intake

Answer

Consumption of saturated fats limited to less than 10% of total energy intake

Answer

Reduction of cholesterol to below 100mg per 1000 kcal per day

Question 2

Which of the following conditions is known to be transmitted vertically?

Accepted Answer

Herpes simplex

Answer

Leprosy

Answer

Tetanus

Answer

Whooping cough

Question 3

Leprosy is not yet eradicated because:

Accepted Answer

There is no effective vaccine.

Answer

It is highly infectious but has low pathogenicity.

Answer

Only humans serve as reservoirs.

Answer

It has a long incubation period.

Question 4

Which of the following is true about the epidemiology of malaria?

Accepted Answer

The mosquito acts as the definitive host.

Answer

The extrinsic incubation period is 0-14 days.

Answer

In India, it is common during January to June.

Answer

Man acts as the definitive host.

Question 5

Which type of Intrauterine Device (IUD) has the lowest expulsion rate?

Accepted Answer

Progestasert

Answer

Lippes loop

Answer

Levonorgestrel-releasing IUD

Answer

Copper T-220

Question 6

Which of the following is an absolute contraindication for combined oral contraceptive pills?

Accepted Answer

Previous history of thromboembolism

Answer

Diabetes mellitus

Answer

Migraine

Answer

Heart disease

Question 7

Which of the following is a non-modifiable risk factor for hypertension?

Accepted Answer

Gender

Answer

Obesity

Answer

Salt intake

Answer

Cultural characteristics acquired over time

Question 8

Which of the following statements is true about endemic typhus?

Accepted Answer

Is transmitted by the bite of fleas

Answer

Is caused by Rickettsia rickettsii

Answer

Has no mammalian reservoir

Answer

Can be cultured in a chemically defined culture medium

Question 9

What is the best method to identify cases of tuberculosis within a community?

Accepted Answer

Sputum smear examination

Answer

Chest X-ray

Answer

Mantoux test

Answer

Sputum culture and sensitivity

Question 10

Malaria recrudescence is defined as:

Accepted Answer

Reappearance of parasitemia after a period of subpatent parasitemia during treatment

Answer

Parasitemia resistant to treatment

Answer

Relapse of infection from dormant liver forms

Answer

Relapse specifically in Plasmodium vivax and ovale infections

Non-Communicable Diseases — MCQs

Non-Communicable Diseases — MCQs

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