Non-Communicable Diseases Practice Questions

Q: What is the principle behind supplementary immunisation services for measles immunisation?

All the above. The principle behind **Supplementary Immunization Activities (SIAs)** for measles is to achieve and maintain high levels of population immunity to interrupt virus transmission. In the context of measles elimination, a single dose of vaccine is insufficient due to primary vaccine failure (approx. 15% if given at 9 months) and gaps in routine coverage. **Explanation of the Correct Answer (D):** The strategy relies on three pillars that constitute the "All the above" answer: 1. **Catch-up Immunization (Option B):** This is a one-time nationwide campaign targeting all children (usually 9 months to 14 years) regardless of their previous vaccination or disease history. It aims to rapidly reduce the pool of susceptible individuals. 2. **Follow-up Immunization (Option C):** These are periodic campaigns (every 2–4 years) targeting children born since the last SIA (usually 9 months to 5 years). It prevents the re-accumulation of susceptible children due to routine coverage gaps. 3. **Maintaining Coverage >95% (Option A):** Measles is highly contagious ($R_0$ of 12–18). To achieve "herd immunity" and interrupt transmission, a sustained coverage of $\geq$95% with two doses of measles-containing vaccine (MCV) is mandatory. **High-Yield Clinical Pearls for NEET-PG:** * **Measles Elimination Goal:** Defined as the absence of endemic measles transmission in a region for $\geq$12 months. * **Outbreak Response Immunization (ORI):** This is the fourth component of SIAs, conducted when an outbreak is detected to limit spread. * **Vitamin A:** Always administered during measles SIAs to reduce morbidity and mortality. * **MCV1 & MCV2:** In India, MCV1 is given at 9–12 months and MCV2 at 16–24 months.

Q: What is the function of glucose in Oral Rehydration Solution (ORS)?

To increase sodium absorption via co-transport.. **Explanation:** The primary function of glucose in Oral Rehydration Solution (ORS) is to facilitate the absorption of sodium and water in the small intestine. This process is based on the **Sodium-Glucose Co-transport mechanism (SGLT-1)**. Even during severe diarrhea (such as in Cholera), this specific transport mechanism remains intact. Glucose molecules bind with sodium ions in a 1:1 ratio; as glucose is actively transported across the intestinal epithelium, it "drags" sodium along with it. This creates an osmotic gradient that promotes the passive absorption of water. **Analysis of Options:** * **Option A (Correct):** Glucose acts as a vehicle for sodium via the SGLT-1 protein, which is the physiological basis of ORS. * **Option B (Incorrect):** While glucose does improve palatability, this is a secondary benefit and not the primary physiological reason for its inclusion. * **Option C (Incorrect):** High osmolality is actually undesirable. Modern **WHO Reduced Osmolarity ORS** (245 mOsm/L) has lower glucose and sodium concentrations than the older formula to prevent osmotic diarrhea and reduce stool output. * **Option D (Incorrect):** The Na-K ATPase pump (sodium-potassium pump) operates on the basolateral membrane to maintain gradients, but glucose does not directly increase its activity; it works on the apical (luminal) side. **Clinical Pearls for NEET-PG:** * **Molar Ratio:** The ideal molar ratio of glucose to sodium in ORS is **1:1**. * **WHO Reduced Osmolarity ORS Composition:** Sodium (75 mmol/L), Glucose (75 mmol/L), Chloride (65 mmol/L), Potassium (20 mmol/L), and Citrate (10 mmol/L). Total Osmolarity = **245 mOsm/L**. * **Trisodium Citrate:** Replaced Sodium Bicarbonate in the formula because it increases shelf life and better corrects acidosis.

Q: What is the duration of infectivity for a patient with diphtheria?

For 15 days after infection. **Explanation:** The duration of infectivity for **Diphtheria** (caused by *Corynebacterium diphtheriae*) typically lasts until the bacilli have disappeared from the secretions, which usually takes **14 to 28 days** (averaging 15 days) from the onset of the disease. 1. **Why Option D is Correct:** In an untreated case, a patient is considered infectious for approximately **2 to 4 weeks**. For examination purposes, **15 days** is the standard benchmark used to define the period of communicability. However, with appropriate antibiotic therapy (Penicillin or Erythromycin), the patient usually becomes non-infectious within 24–48 hours. 2. **Why Other Options are Incorrect:** * **Option A:** Diphtheria is characterized by a "barking" cough (croup) due to the pseudomembrane, but infectivity is linked to the presence of the bacilli in the throat/nasopharynx, not the clinical symptom of coughing. * **Option B:** Fever in diphtheria is usually low-grade. Infectivity persists long after the patient becomes afebrile. * **Option C:** Diphtheria is an acute infection. While "chronic carriers" exist, the disease itself is not lifelong. **High-Yield NEET-PG Pearls:** * **Schick Test:** Used to demonstrate immunity/susceptibility to Diphtheria. * **Virulence Test:** Elek's gel precipitation test is used to detect toxin production. * **Culture Media:** Loffler’s Serum Slope (rapid growth) and Potassium Tellurite agar (black colonies). * **Case Definition:** Presence of a greyish-white **pseudomembrane** (cannot be easily scraped off; bleeds on touch). * **Contact Management:** All contacts should be kept under surveillance for 7 days and given a prophylactic dose of Erythromycin.

Q: Zika virus is transmitted through which vector?

Aedes mosquito. **Explanation:** The **Zika virus** is a flavivirus primarily transmitted to humans through the bite of an infected **Aedes mosquito**, specifically *Aedes aegypti* and *Aedes albopictus*. These are the same vectors responsible for transmitting Dengue, Chikungunya, and Yellow Fever. These mosquitoes are "day-biters," showing peak activity during early morning and late afternoon. **Analysis of Options:** * **B. Aedes mosquito (Correct):** As the primary vector, it thrives in urban environments and breeds in stagnant clean water (e.g., flower pots, discarded tires). * **A. Anopheles mosquito:** This is the primary vector for **Malaria**. It typically bites at night and breeds in clean, stagnant, or slow-moving water. * **C. Culex mosquito:** Known as the "nuisance mosquito," it transmits **Japanese Encephalitis, West Nile Virus, and Lymphatic Filariasis** (Wuchereria bancrofti). It breeds in dirty, polluted water. * **D. Fruit fly:** While used extensively in genetic research (*Drosophila*), it is not a vector for human viral pathogens like Zika. **High-Yield Clinical Pearls for NEET-PG:** * **Modes of Transmission:** Beyond the mosquito vector, Zika is unique because it can be transmitted **sexually**, via **blood transfusion**, and **transplacentally** (vertical transmission). * **Congenital Zika Syndrome:** Infection during pregnancy is strongly linked to **microcephaly** and other severe brain defects in the fetus. * **Neurological Association:** In adults, Zika infection is associated with an increased risk of **Guillain-Barré Syndrome (GBS)**. * **Diagnosis:** RT-PCR is used for acute phase detection (blood/urine), while Serology (IgM) is used for later diagnosis.

Q: What is an important indicator to measure the incidence of malaria in a community?

Annual parasite incidence. **Explanation:** **Annual Parasite Incidence (API)** is the most sensitive and widely used indicator to measure the **incidence** of malaria in a community. It represents the number of confirmed malaria cases per 1,000 population per year. Since "incidence" refers to the occurrence of new cases, API—which tracks laboratory-confirmed cases over a specific timeframe—is the gold standard for monitoring the malaria burden and the effectiveness of control programs. **Analysis of Options:** * **Slide Positivity Rate (SPR):** This measures the percentage of blood slides found positive among the total slides examined. While useful for monitoring trends, it is heavily dependent on the total number of slides collected (fever surveillance) rather than the actual population at risk. * **Annual Falciparum Incidence (AFI):** This specifically measures the incidence of *P. falciparum* cases. While critical for assessing the severity of the malaria situation (as falciparum is more lethal), it does not represent the total incidence of all malaria species (e.g., *P. vivax*). * **Infant Parasite Rate (IPR):** This measures the prevalence of malaria parasites in infants (below 1 year). It is considered the best indicator for measuring **recent transmission** in a locality, as infants are unlikely to have traveled or had long-standing infections. **High-Yield Facts for NEET-PG:** * **API Formula:** (Total confirmed cases in a year / Total population under surveillance) × 1000. * **Target:** Under the National Framework for Malaria Elimination, an API of **<1 per 1,000 population** is the threshold for moving into the elimination phase. * **Annual Blood Examination Rate (ABER):** Measures the efficiency of surveillance; it should ideally be **10% or more**. * **Indicator of Endemicity:** Spleen rate in children (2–9 years) is traditionally used to classify the endemicity of malaria in an area.

Q: What is the Body Mass Index (BMI) threshold for obesity?

Greater than or equal to 30. **Explanation:** The Body Mass Index (BMI), or Quetelet index, is the standard epidemiological tool used to classify weight status in adults. It is calculated as weight in kilograms divided by the square of height in meters ($kg/m^2$). **Why Option D is Correct:** According to the **World Health Organization (WHO)** classification, a BMI **$\geq$ 30 $kg/m^2$** is the definitive threshold for **Obesity**. This category is further subdivided into Class I (30.0–34.9), Class II (35.0–39.9), and Class III or Morbid Obesity ($\geq$ 40.0). **Analysis of Incorrect Options:** * **Option A ($\geq$ 20):** This falls within the **Normal range** (18.5–24.9 $kg/m^2$). A BMI below 18.5 is classified as underweight. * **Option B ($\geq$ 50):** This represents **Super Obesity**, a severe sub-category of Class III obesity, but it is not the baseline threshold for the diagnosis. * **Option C ($\geq$ 40):** This is the threshold for **Class III Obesity** (Morbid Obesity), indicating a much higher risk of metabolic and cardiovascular complications. **High-Yield Clinical Pearls for NEET-PG:** 1. **Asian-Indian Guidelines:** Due to a higher percentage of body fat and visceral adiposity at lower BMIs, the thresholds for Indians are lower: * **Overweight:** 23.0–24.9 $kg/m^2$ * **Obesity:** $\geq$ 25.0 $kg/m^2$ 2. **Ponderal Index:** Calculated as $Weight (kg) / Height^3 (m^3)$. It is considered a more sensitive indicator of thinness/wasting. 3. **Waist-Hip Ratio (WHR):** A better predictor of cardiovascular risk than BMI. Risk increases if WHR is **> 0.9 in men** or **> 0.85 in women**.

Q: A vasectomy is considered to have failed if the vasectomized person's wife gives birth to a child ten months after the operation. Which one of the following is the most probable cause?

Surgical failure. ### Explanation **Correct Answer: B. Surgical failure** The primary reason for a pregnancy occurring **ten months** after a vasectomy is typically **surgical failure**. In this context, surgical failure refers to the failure of the surgeon to correctly identify and ligate both vasa deferentia during the procedure. Often, a different anatomical structure (such as a nerve or a blood vessel) is mistakenly ligated instead of the vas deferens, leaving the pathway for sperm intact. **Analysis of Options:** * **A. Failure to use a condom:** Vasectomy is not immediately effective. Sperm remain in the distal tract for several weeks. However, this "residual sperm" is usually cleared after **20-30 ejaculations or 3 months**. A pregnancy at 10 months is well beyond this "danger period," making this an unlikely cause. * **C. Recannalisation:** While spontaneous re-joining of the cut ends of the vas deferens can occur, it is statistically much rarer than initial surgical error. In the context of standard medical examinations, "surgical failure" is the prioritized answer for early post-operative failures. * **D. Extramarital contact:** In medical ethics and examination logic, clinical or surgical reasons must be ruled out before assuming social or behavioral factors. **Clinical Pearls for NEET-PG:** * **Effectiveness:** Vasectomy is more effective than tubectomy, but it is **not** immediate. * **Post-op Advice:** The patient must use an additional contraceptive method (e.g., condoms) for **3 months** or until **two consecutive semen analyses** show azoospermia. * **The "3-Month Rule":** This is the high-yield timeframe for clearing residual sperm stored in the seminal vesicles. * **Failure Rate:** The failure rate of vasectomy is approximately 0.1% to 0.15%.

Q: Which of the following vaccines is NOT included in the national immunization schedule?

Hepatitis A. **Explanation:** The **National Immunization Schedule (NIS)** in India, under the Universal Immunization Programme (UIP), focuses on protecting the pediatric and obstetric population against high-morbidity and high-mortality vaccine-preventable diseases (VPDs). **Why Hepatitis A is the correct answer:** Hepatitis A is currently **not** part of the National Immunization Schedule in India. While the vaccine is available and recommended by the Indian Academy of Pediatrics (IAP) for individual use, it is not provided free of cost under the government’s routine program. This is primarily due to the high endemicity of Hepatitis A in India, where most children develop natural immunity through subclinical exposure at a young age. **Analysis of Incorrect Options:** * **Tetanus Toxoid (TT):** Now replaced by Tetanus & adult Diphtheria (Td) vaccine, it is a core component of the NIS, administered to pregnant women and at ages 10 and 16 years. * **Oral Polio Vaccine (OPV):** A cornerstone of the Pulse Polio Immunization program, it is given at birth (zero dose) and at 6, 10, and 14 weeks. * **Measles:** Administered as the Measles-Rubella (MR) vaccine under the NIS at 9 months and 16–24 months. **High-Yield NEET-PG Pearls:** * **Hepatitis B** is included in the NIS (Birth dose + Pentavalent vaccine), but **Hepatitis A** is not. * **Rotavirus and PCV (Pneumococcal Conjugate Vaccine)** are the latest major additions to the nationwide NIS. * **Fractional IPV (fIPV)** is given intradermally at 6, 14 weeks, and 9 months. * **JE Vaccine** is included in the NIS but only in **endemic districts**.

Question 1

What is the principle behind supplementary immunisation services for measles immunisation?

Accepted Answer

All the above

Answer

Maintaining coverage above 95%

Answer

Catch-up immunisation

Answer

Follow-up immunisation

Question 2

What is the function of glucose in Oral Rehydration Solution (ORS)?

Accepted Answer

To increase sodium absorption via co-transport.

Answer

To impart a sweet taste to the ORS.

Answer

To increase the osmolality of the ORS.

Answer

To increase the activity of the sodium-potassium pump.

Question 3

What is the duration of infectivity for a patient with diphtheria?

Accepted Answer

For 15 days after infection

Answer

Until the cough subsides

Answer

Until the patient is febrile

Answer

Lifelong

Question 4

As per the National Population Policy 2000, what is the medium-term objective regarding the total fertility rate?

Accepted Answer

Bring the total fertility rate to replacement level by 2010.

Answer

Bring the total fertility rate to replacement level by 2008.

Answer

Bring the total fertility rate to replacement level by 2012.

Answer

Bring the total fertility rate to replacement level by 2014.

Question 5

Zika virus is transmitted through which vector?

Accepted Answer

Aedes mosquito

Answer

Anopheles mosquito

Answer

Culex mosquito

Answer

Fruit fly

Question 6

What is an important indicator to measure the incidence of malaria in a community?

Accepted Answer

Annual parasite incidence

Answer

Slide positivity rate

Answer

Annual falciparum incidence

Answer

Infant parasite rate

Question 7

What is the Body Mass Index (BMI) threshold for obesity?

Accepted Answer

Greater than or equal to 30

Answer

Greater than or equal to 20

Answer

Greater than or equal to 50

Answer

Greater than or equal to 40

Question 8

Sentinel surveillance of HIV is done for all the following except?

Accepted Answer

Monitor effectiveness of control program

Answer

Disease trend

Answer

High risk group

Answer

Population at risk

Question 9

A vasectomy is considered to have failed if the vasectomized person's wife gives birth to a child ten months after the operation. Which one of the following is the most probable cause?

Accepted Answer

Surgical failure

Answer

Failure of the husband to use a condom after vasectomy

Answer

Recannalisation

Answer

Wife had extramarital contact

Question 10

Which of the following vaccines is NOT included in the national immunization schedule?

Accepted Answer

Hepatitis A

Answer

Tetanus Toxoid (TT)

Answer

Oral Polio Vaccine (OPV)

Answer

Measles

Non-Communicable Diseases — MCQs

Non-Communicable Diseases — MCQs

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