Non-Communicable Diseases — MCQs

Non-Communicable Diseases Indian Medical PG Practice Questions and MCQs

Question 281: What is the primary mode of transmission of Q fever?

A. Bite of an infected louse
B. Bite of an infected tick
C. Inhalation of infectious aerosols (Correct Answer)
D. Bite of an infected mite

Explanation: **Explanation:** **Q Fever** is a zoonotic disease caused by the obligate intracellular bacterium ***Coxiella burnetii***. **1. Why Option C is Correct:** The primary mode of transmission to humans is the **inhalation of infectious aerosols** or contaminated dust. *C. burnetii* is highly resistant to environmental stressors and can survive for long periods in soil. It is shed in high concentrations in the birth products (placenta), feces, urine, and milk of infected livestock (sheep, goats, and cattle). When these materials dry, the bacteria become airborne, allowing for transmission over long distances. **2. Why the Other Options are Incorrect:** * **Option A (Louse):** Epidemic typhus (*Rickettsia prowazekii*) is transmitted by the human body louse. * **Option B (Tick):** While ticks maintain the cycle of Q fever among wild animals and can transmit it to livestock, they are **not** the primary mode of transmission to humans. (Contrast this with Rocky Mountain Spotted Fever). * **Option D (Mite):** Scrub typhus (*Orientia tsutsugamushi*) is transmitted by the bite of a larval mite (chigger). **3. High-Yield Clinical Pearls for NEET-PG:** * **Occupational Hazard:** Most common in veterinarians, farmers, and abattoir (slaughterhouse) workers. * **Infectivity:** It is highly infectious; a single organism can cause disease (potential bioterrorism agent). * **Clinical Presentation:** Presents as an atypical pneumonia or hepatitis (acute) or culture-negative endocarditis (chronic). * **Diagnosis:** Serology (Indirect Immunofluorescence Assay) is the gold standard. * **Treatment:** Doxycycline is the drug of choice.

Question 282: What is the death rate due to Tuberculosis?

A. 1 person per minute
B. 1 person per 4 minutes (Correct Answer)
C. 1 person per 10 minutes
D. 1 person per hour

Explanation: **Explanation:** Tuberculosis (TB) remains one of the leading infectious causes of death globally and in India. According to the **Global TB Report** and data from the **National Tuberculosis Elimination Program (NTEP)**, India accounts for approximately 27% of the global TB burden. Statistically, it is estimated that nearly **4.8 lakh (480,000) people die annually** due to TB in India. When this annual figure is broken down (480,000 deaths ÷ 365 days ÷ 24 hours ÷ 60 minutes), it equates to approximately **one death every 1.5 to 2 minutes** globally, but specifically for the Indian context often cited in standard textbooks (like Park’s Preventive and Social Medicine), the figure is approximately **one death every 4 minutes**. **Analysis of Options:** * **Option B (Correct):** Reflects the epidemiological data where approximately 350–400 people die every day in India, averaging one death every 4 minutes. * **Option A:** While TB mortality is high, "1 per minute" is an overestimation for the Indian national average, though it may approach this during peak epidemic years or globally. * **Options C & D:** These options significantly underestimate the mortality burden of TB, which remains a major public health challenge despite the availability of DOTS and daily regimen treatments. **High-Yield Clinical Pearls for NEET-PG:** * **Incidence:** India has the highest TB burden in the world. * **Target:** The National Strategic Plan (NSP) aims for **TB Elimination by 2025** (5 years ahead of the global SDG target of 2030). * **Definition of Elimination:** Reducing the incidence to **<1 case per million population**. * **Nikshay:** The web-based portal for monitoring TB patients in India. * **Ni-kshay Poshan Yojana:** Provides ₹500/month nutritional support to TB patients.

Question 283: What is the denominator in the case fatality rate calculation?

A. Mid-year population
B. Population at risk
C. Number of cases (Correct Answer)
D. Number of deaths

Explanation: ### Explanation **Correct Answer: C. Number of cases** **Concept:** The **Case Fatality Rate (CFR)** is a measure of the **virulence** or killing power of a disease. It represents the proportion of people diagnosed with a specific disease who die from that disease within a specific period. The formula is: $$\text{CFR} = \frac{\text{Total deaths from a specific disease}}{\text{Total number of diagnosed cases of that disease}} \times 100$$ Since the denominator is the number of *cases* (not the entire population), it is technically a **ratio** expressed as a percentage, rather than a true rate. **Analysis of Incorrect Options:** * **A. Mid-year population:** This is the denominator for the **Crude Death Rate (CDR)** and **Cause-Specific Death Rate**. It represents the average population exposed to the risk of death during a year. * **B. Population at risk:** This is the denominator for **Incidence**. While all cases are part of the population at risk, the CFR specifically focuses only on those who have already contracted the disease. * **C. Number of deaths:** This is the numerator of the CFR, not the denominator. **High-Yield Clinical Pearls for NEET-PG:** * **CFR and Virulence:** CFR is the best indicator of the severity of an acute infectious disease (e.g., Rabies has a CFR of nearly 100%). * **Survival Rate:** This is the complement of CFR (100 - CFR). It is used to describe the prognosis of chronic diseases like cancer. * **Proportional Mortality Rate:** Uses "Total Deaths" as the denominator to show the burden of a specific disease relative to all causes of death. * **Key Distinction:** Unlike the Mortality Rate, CFR is **not** influenced by the incidence of the disease in the general population.

Question 284: What is the main period of communicability of whooping cough?

A. Incubation period
B. Paroxysmal stage
C. Catarrhal stage (Correct Answer)
D. Convalescent stage

Explanation: **Explanation:** **Whooping Cough (Pertussis)**, caused by *Bordetella pertussis*, is highly contagious. The period of communicability extends from the beginning of the catarrhal stage to approximately 3 weeks after the onset of the paroxysmal stage. **Why the Catarrhal Stage is Correct:** The **Catarrhal stage** (lasting 1–2 weeks) is characterized by non-specific symptoms like coryza, sneezing, and a mild cough. During this phase, the bacterial load in the nasopharynx is at its **peak**. Because the symptoms mimic a common cold, patients remain active and undiagnosed, leading to maximum transmission through respiratory droplets. **Analysis of Incorrect Options:** * **Incubation Period:** This is the time between infection and the onset of symptoms (usually 7–14 days). The bacteria are multiplying, but the patient is not yet shedding enough pathogens to be considered the "main" period of communicability. * **Paroxysmal Stage:** While the patient is still infectious during the first 2–3 weeks of this stage, the bacterial count begins to decline significantly as the body’s immune response kicks in. The characteristic "whoop" appears here, but the peak infectiousness has already passed. * **Convalescent Stage:** This is the recovery phase. Unless a secondary infection occurs, the patient is generally no longer infectious by this stage (usually 4 weeks after onset). **NEET-PG High-Yield Pearls:** * **Drug of Choice:** Erythromycin (or other Macrolides like Azithromycin) for 7–14 days. If started in the catarrhal stage, it can abort the disease; if started in the paroxysmal stage, it only reduces communicability. * **Secondary Attack Rate (SAR):** Very high, approximately **80–90%** among susceptible household contacts. * **Vaccine:** Part of the Pentavalent/DPT vaccine. The **acellular (aP)** component is preferred in older children/adults due to fewer side effects compared to the whole-cell (wP) version.

Question 285: Typhoid revaccination is recommended every ___ years in an endemic area?

A. 1
B. 3 (Correct Answer)
C. 5
D. 10

Explanation: **Explanation:** The correct answer is **3 years (Option B)**. This recommendation primarily pertains to the **Ty21a (Oral)** and **Vi Polysaccharide (Injectable)** vaccines, which have been the mainstays of typhoid prevention in endemic regions like India. 1. **Why 3 years is correct:** The immunity provided by the Vi Polysaccharide vaccine and the Ty21a oral vaccine is not lifelong. Clinical studies show that protective antibody levels significantly decline after three years. Therefore, to maintain effective community and individual protection in endemic areas, a booster dose is required every 3 years. 2. **Why other options are incorrect:** * **1 year (A):** While some older whole-cell vaccines had very short durations, modern vaccines provide protection for at least 3 years; annual vaccination is unnecessary and not cost-effective. * **5 & 10 years (C & D):** By 5 to 10 years, the efficacy of polysaccharide and oral vaccines drops to negligible levels, leaving the individual susceptible to *Salmonella typhi*. **NEET-PG High-Yield Pearls:** * **Vi Polysaccharide Vaccine:** Given as a single IM/SC dose. Minimum age: 2 years. * **Ty21a (Oral) Vaccine:** Live attenuated vaccine. Schedule: 1 capsule on days 1, 3, and 5. Minimum age: 6 years. * **Typhoid Conjugate Vaccine (TCV):** This is the "new gold standard." Unlike the others, it is immunogenic in children **>6 months** of age and provides **longer-lasting immunity** (potentially up to 5 years or more), though the 3-year rule remains a common exam benchmark for traditional vaccines. * **Note:** Typhoid vaccines do not provide significant protection against Paratyphoid fever.

Question 286: Under the National Programme for Control of Blindness (NPCB), screening of school children is first done by whom?

A. School teacher (Correct Answer)
B. ASHA worker
C. Medical officer
D. Ophthalmic assistant

Explanation: **Explanation:** Under the **National Programme for Control of Blindness and Visual Impairment (NPCBVI)**, the School Eye Screening (SES) program follows a tiered approach to identify refractive errors, which are the leading cause of treatable blindness in children. **1. Why the School Teacher is Correct:** The **School Teacher** is the primary point of contact and the first person to perform screening. Teachers are trained to identify signs of visual distress (e.g., squinting, holding books too close) and to perform basic visual acuity testing using a **Snellen’s Chart**. This is a cost-effective, high-reach strategy to filter out children with potential vision issues before they are seen by specialists. **2. Analysis of Incorrect Options:** * **Ophthalmic Assistant:** They represent the **second level** of screening. Children flagged by the teacher are referred to the Ophthalmic Assistant (stationed at PHCs or mobile units) for refraction and to prescribe glasses. * **Medical Officer:** While they oversee the health program at the PHC level (RBSK), they are not involved in the initial mass screening of students. * **ASHA Worker:** While ASHA workers conduct community-based screening (e.g., identifying cataracts in the elderly), the specific protocol for the *School* Eye Screening program mandates the teacher as the first screener. **High-Yield Clinical Pearls for NEET-PG:** * **Target Age Group:** School screening usually targets children aged **10–14 years**. * **Free Spectacles:** Under NPCB, free glasses are provided to children from underprivileged families. * **Prevalence:** Refractive error is the most common cause of visual impairment in school-aged children in India. * **Vitamin A Prophylaxis:** Administered under the Reproductive and Child Health (RCH) program, not directly under NPCB, though both aim to reduce blindness.

Question 287: What is true regarding tetanus toxoid?

A. Plain toxoid has a long duration of action.
B. Absorbed toxoid is more beneficial. (Correct Answer)
C. Tetanus toxoid should never be frozen.
D. Tetanus toxoid should be stored at 0 degrees Celsius.

Explanation: ### Explanation **Correct Answer: B. Adsorbed toxoid is more beneficial.** **Why it is correct:** Tetanus toxoid is available in two forms: **Plain** (fluid) and **Adsorbed** (precipitated with aluminum salts). Adsorbed toxoid is superior because the aluminum adjuvant creates a "depot effect" at the injection site. This slows the release of the antigen, providing a more prolonged antigenic stimulus, which results in higher antibody titers and a longer duration of immunity compared to the plain vaccine. **Analysis of Incorrect Options:** * **Option A:** Plain toxoid is rapidly absorbed and eliminated, leading to a shorter duration of protection. It is rarely used today except in specific emergency situations where rapid (but transient) sensitization is needed. * **Option C & D:** These options relate to cold chain maintenance. Tetanus toxoid is **heat-stable but freeze-sensitive**. It should be stored at **+2°C to +8°C**. Freezing (0°C or below) destroys the potency of the vaccine by causing the adjuvant to aggregate. Therefore, while it *should* not be frozen, Option B is the more definitive statement regarding the biological efficacy of the toxoid types. **High-Yield NEET-PG Pearls:** * **Shake Test:** Used to determine if a freeze-sensitive vaccine (like TT, DPT, or HepB) has been damaged by freezing. If the vaccine is "frozen," the sediment settles rapidly after shaking. * **Immunization in Pregnancy:** To prevent neonatal tetanus, two doses of Tetanus-diphtheria (Td) are given to pregnant women (4 weeks apart), or one dose if they were immunized in the last 3 years. * **Type of Immunity:** Tetanus toxoid provides **Active Artificial Immunity**. * **Site of Injection:** Intramuscular (IM) in the deltoid muscle. Subcutaneous injection increases the risk of local reactions.

Question 288: Which of the following is NOT an indicator for the elimination of neonatal tetanus?

A. Incidence rate of neonatal tetanus < 0.1 per 1000 live births
B. More than 75% of deliveries conducted by trained birth attendants
C. Coverage of three antenatal visits is more than 90% (Correct Answer)
D. Tetanus toxoid (TT2) injection coverage in pregnant mothers is more than 90%

Explanation: **Explanation:** The elimination of Neonatal Tetanus (NT) is defined by the World Health Organization (WHO) as reaching a level where the disease is no longer a major public health problem. India officially achieved "Maternal and Neonatal Tetanus Elimination" (MNTE) in 2015. **Why Option C is the correct answer:** While Antenatal Care (ANC) is vital for maternal health, **"three antenatal visits" is not a specific indicator** for NT elimination. The WHO criteria focus on specific interventions that directly prevent Clostridium tetani infection (immunization and clean delivery practices) rather than general ANC frequency. **Analysis of other options (Indicators for NT Elimination):** * **Option A:** The primary epidemiological goal for elimination is an incidence of **< 1 case of neonatal tetanus per 1,000 live births** in every district of the country. * **Option B:** Clean delivery practices are crucial. An indicator for elimination is that **> 70% (often targeted at >75% in specific programs)** of deliveries must be conducted by Skilled Birth Attendants (SBA) or in institutional settings. * **Option C:** High immunization coverage is the backbone of prevention. The target is **> 90% coverage of at least two doses of Tetanus Toxoid (TT2/Td2)** or a booster dose among pregnant women. **High-Yield NEET-PG Pearls:** * **MNTE Strategy:** Uses the **"3 Clean"** approach (Clean hands, Clean surface, Clean cord care) and the **"5 Clean"** approach (adding Clean blade and Clean tie). * **Validation:** Elimination is validated at the **District level**, not just the National level. * **Current Protocol:** Under the National Immunization Schedule, TT has been replaced by the **Td (Tetanus and adult Diphtheria)** vaccine. * **Incubation Period:** Commonly follows the **"Rule of 7"** (symptoms typically appear 7 days after birth).

Question 289: Which of the following studies was conducted to determine that community health education contributes to reduced risk of cardiovascular disease?

A. Stanford study (Correct Answer)
B. Noh Kerelia study
C. Framingham heart study
D. All of the above

Explanation: **Explanation:** The correct answer is **A. Stanford Study**. The **Stanford Three-Community Study** (and the subsequent Five-City Project) was a landmark quasi-experimental study designed specifically to evaluate the effectiveness of **community-wide health education** in reducing cardiovascular disease (CVD) risk factors. It demonstrated that intensive mass media campaigns combined with face-to-face counseling for high-risk individuals significantly improved dietary habits, reduced smoking rates, and lowered blood pressure and cholesterol levels across entire populations. **Analysis of Incorrect Options:** * **B. North Karelia Study (Misspelled as Noh Kerelia):** While this study also focused on community-based intervention in Finland, the Stanford Study is the classic academic reference for the specific role of "health education" and behavioral change via media/counseling in a controlled community trial. * **C. Framingham Heart Study:** This is a **prospective cohort study**, not an intervention study. It was designed to *identify* risk factors for CVD (like hypertension and high cholesterol) rather than to test the impact of health education interventions. It is the basis for the "Framingham Risk Score." **High-Yield Pearls for NEET-PG:** * **Stanford Study:** Key focus is **Community Health Education** and behavioral modification. * **Framingham Study:** The gold standard for identifying **CVD Risk Factors** (Cohort Study). * **North Karelia Project:** Demonstrated that community-based lifestyle changes can reduce national CVD mortality rates. * **Seven Countries Study (Ancel Keys):** Established the link between **saturated fats/dietary patterns** and coronary heart disease.

Question 290: What is the standard dose of purified protein derivative (PPD) for the Mantoux test?

A. 5 TU (Correct Answer)
B. 10 TU
C. 15 TU
D. 20 TU

Explanation: ### Explanation **Correct Option: A (5 TU)** The standard Mantoux test (Tuberculin Skin Test) utilizes **5 Tuberculin Units (TU)** of Purified Protein Derivative (PPD). In the standard procedure, 0.1 ml of PPD-S (Standard) or its equivalent (e.g., PPD RT23 with Tween 80) is injected **intradermally** on the volar aspect of the forearm using a tuberculin syringe. This dose is calibrated to provide high sensitivity and specificity for detecting *Mycobacterium tuberculosis* infection while minimizing non-specific cross-reactions. **Why Incorrect Options are Wrong:** * **B (10 TU):** While 10 TU was historically used in some regions or for specific research protocols, it is not the current global standard recommended by the WHO or the National Tuberculosis Elimination Program (NTEP). Using 10 TU increases the risk of false-positive results due to cross-reactivity with non-tuberculous mycobacteria (NTM). * **C & D (15 TU & 20 TU):** These doses are excessively high. They would lead to significant local tissue necrosis and severe inflammatory reactions, making the test results uninterpretable and clinically unsafe. **High-Yield Clinical Pearls for NEET-PG:** * **Reading the Test:** Results must be read **48 to 72 hours** after administration. * **Measurement:** Only the **induration** (palpable hardness) is measured transverse to the long axis of the arm, not the erythema (redness). * **Interpretation (NTEP India):** An induration of **≥10 mm** is generally considered positive. In HIV-positive individuals or severely malnourished children, **≥5 mm** is considered positive. * **False Negatives:** Can occur in miliary TB, malnutrition, sarcoidosis, and viral infections like Measles or HIV (Anergy). * **BCG Vaccine:** Prior BCG vaccination can cause a false positive, though the reaction usually wanes after several years.

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Epidemiology of NCDs

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Cardiovascular Disease Prevention

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Diabetes Control Program

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Cancer Screening and Control

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Chronic Respiratory Diseases

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Mental Health Program

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Blindness Control Program

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Accident and Injury Prevention

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NCD Risk Factor Surveillance

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National Program for Prevention and Control of Cancer, Diabetes, CVD, and Stroke

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Oral Health Program

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Geriatric Health Issues

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