NEET-PG 2012 Practice Questions

Q: Which disease is most closely associated with intensive international surveillance for global eradication?

Polio. **Polio** - **Polio** has been the focus of an intensive global eradication campaign, requiring robust **international surveillance** to track cases, mutations, and vaccine-derived polioviruses. - The **Global Polio Eradication Initiative (GPEI)**, a major international collaboration, relies heavily on coordinated surveillance efforts to ensure no wild poliovirus remains undetected. *Hepatitis* - While **hepatitis** is a significant global health burden, particularly hepatitis B and C, it is not subject to the same level of internationally coordinated, aggressive surveillance aimed at **global eradication** as polio. - Surveillance for hepatitis often focuses on prevalence, incidence, and risk factors at national and regional levels rather than a centralized, real-time eradication tracking system. *TB* - **Tuberculosis (TB)** is a major global health concern, and there are international efforts for control and elimination, but it is not currently targeted for **global eradication** in the same manner as polio. - Surveillance for TB often involves tracking drug-resistant strains and treatment outcomes, but it doesn't involve the immediate, outbreak-focused international alert system seen with diseases like polio or novel pandemics. *Leprosy* - **Leprosy** is a neglected tropical disease, and while there are international efforts for its control and elimination, primarily led by the WHO, it does not involve the same level of intensive, real-time global surveillance for eradication as **polio**. - Surveillance for leprosy is typically focused on case detection, treatment completion, and identifying areas with high endemicity rather than rapid international notification of individual cases for eradication purposes.

Q: Measles vaccination is given at -

9 months. ***9 months*** - The first dose of the **measles vaccine (MMR)** is typically administered at **9 months** of age in many national immunization programs. - This timing is chosen because maternal antibodies, which can interfere with vaccine effectiveness, generally wane by this age. *At birth* - Vaccines given at birth, such as **Hepatitis B** and **BCG**, target diseases with early exposure risks or have efficacy despite maternal antibodies. - Giving measles vaccine at birth would be ineffective due to the presence of **maternal antibodies** that neutralize the vaccine virus. *4 weeks* - This age is generally too early for measles vaccination as significant levels of **maternal antibodies** are often still present, which would reduce the vaccine's efficacy. - Other vaccines, like the rotavirus vaccine, might be given around this age, but not measles. *8 weeks* - While maternal antibodies might be decreasing, 8 weeks of age is still generally considered too early for optimal measles vaccine response. - Many primary vaccine series (e.g., DTaP, IPV, Hib) begin at 6-8 weeks, but measles is usually delayed further for better efficacy and seroconversion rates.

Q: What are the serogroups covered by the bivalent meningococcal vaccine?

Serogroup A and C. ***Serogroup A and C*** - The **bivalent meningococcal vaccine** specifically targets and provides protection against **Neisseria meningitidis** serogroups **A and C**. - This vaccine is crucial for preventing invasive meningococcal disease caused by these prevalent strains, particularly in the African meningitis belt. - Examples include **meningococcal AC conjugate vaccines** used in mass vaccination campaigns. *Serogroup A* - While **Serogroup A** is one of the types covered by bivalent vaccines, it is not the only one. - A vaccine covering only Serogroup A would be a **monovalent vaccine**, not bivalent. *Serogroup W* - **Serogroup W** is covered by **quadrivalent meningococcal vaccines** (e.g., MenACWY) which protect against serogroups A, C, W, and Y. - It is **not included** in **bivalent** formulations. *Serogroup C* - While **Serogroup C** is one of the types covered by bivalent vaccines, it is not the only one. - A vaccine covering only Serogroup C would be a **monovalent vaccine**, not bivalent.

Q: Which is the main vector of Dengue?

A. aegypti. ***A. aegypti*** - **Aedes aegypti** is the primary vector responsible for transmitting the **Dengue virus** to humans. - It is a **day-biting mosquito** found predominantly in tropical and subtropical regions. *Culex* - **Culex mosquitoes** are known vectors for diseases like **Japanese encephalitis**, **West Nile virus**, and **filariasis**. - They are generally **night-biting** and do not play a significant role in Dengue transmission. *Anopheles* - **Anopheles mosquitoes** are the primary vectors for **malaria** in humans. - They are not associated with the transmission of the Dengue virus. *Aedes scutellaris* - While part of the **Aedes genus**, **Aedes scutellaris** is a secondary vector for Dengue in the **Pacific region**. - The main vector for Dengue globally remains **Aedes aegypti**, followed by **Aedes albopictus** in some regions.

Q: Which of the following is a zoonotic disease?

Hydatid cyst. ***Hydatid cyst*** - This disease is caused by the larval stage of the tapeworm **Echinococcus granulosus**, which completes its life cycle in dogs and sheep. - Humans can become infected by ingesting material contaminated with **Echinococcus eggs**, typically from contact with infected dogs or contaminated food/water, making it a zoonotic disease. *Malaria* - Malaria is transmitted by the **Anopheles mosquito** biting infected humans and then uninfected humans. - While it involves a vector, its primary reservoir is humans and it is not typically considered zoonotic as there is no animal-to-human transmission from a non-human primary reservoir. *Filariasis* - Filariasis is spread by various mosquito vectors (e.g., **Culex, Anopheles, Aedes**) that transmit parasitic worms to humans. - The life cycle primarily involves humans and mosquitos, and it is not classified as a zoonotic disease. *Dengue fever* - Dengue fever is a viral infection transmitted by **Aedes mosquitoes** (primarily *Aedes aegypti* and *Aedes albopictus*) between humans. - Similar to malaria, while it involves a vector, the primary reservoir is humans, and it is not considered zoonotic.

Q: Which of the following statements about the Late Expanding Phase of the Demographic Cycle is TRUE?

Death Rate declines more than Birth Rate. ***Death Rate declines more than Birth Rate*** - In the **Late Expanding Phase**, the **birth rate** remains high, while the **death rate** continues to fall **rapidly** due to improved healthcare, sanitation, and nutrition. - This significant decline in the death rate, coupled with a still high birth rate, results in a rapid and substantial increase in **population growth** (demographic explosion). - The key characteristic is the **greater rate of decline** in death rate compared to birth rate. *Birth Rate remains consistently high while Death Rate starts to decline significantly* - The word **"starts"** is the critical error here - it describes the **Early Expanding Phase**, not the Late Expanding Phase. - In the **Late Expanding Phase**, the death rate has *already been declining* and continues to decline rapidly. - The death rate decline **begins** in the Early Expanding Phase, not the Late Expanding Phase. *Death Rate becomes significantly lower than Birth Rate during this phase* - While this statement is true, it describes a **consequence** rather than the defining characteristic of the Late Expanding Phase. - This condition exists throughout the expanding phases, making it less specific. - The defining feature is the **rate of decline** of death rate being greater than any decline in birth rate. *Birth Rate remains higher than Death Rate, leading to population growth* - This statement is true but **too generic** - it applies to all expanding phases where population growth occurs. - It does not specifically distinguish the **Late Expanding Phase** from the Early Expanding Phase. - The unique feature of the Late Expanding Phase is the **rapid and dramatic decline** in death rate while birth rate remains high.

Q: HIV post exposure prophylaxis should be started within?

72 hrs. ***72 hrs*** - **Post-exposure prophylaxis (PEP)** aims to prevent HIV infection after potential exposure and should ideally be initiated as soon as possible, but no later than **72 hours** after exposure [1]. - Starting PEP within this window significantly increases its effectiveness in preventing HIV seroconversion. *1-2 hrs* - While initiating PEP as soon as possible is crucial, stating it must be within **1-2 hours** can be misleading as the window of effectiveness extends beyond this. - This timeframe might be an ideal, but not the absolute crucial limit for efficacy. *14 hrs* - This timeframe is **too restrictive** for the recommended window for PEP initiation. - Missing the opportunity within **14 hours** does not negate the effectiveness of PEP if started within the broader 72-hour window. *18 hrs* - Similar to **14 hours**, **18 hours** is an unnecessarily strict limit for PEP initiation. - Guidelines universally support starting PEP up to **72 hours** post-exposure for optimal benefit [1].

Q: What is the correct order of application of reagents in the complete Gram staining procedure?

Gentian violet → Iodine → Alcohol/Acetone → Safranin. **Gentian violet → Iodine → Alcohol/Acetone → Safranin** - **Gentian violet** (or crystal violet) is the **primary stain** that colors all cells purple. - **Iodine** acts as a **mordant**, forming a crystal violet-iodine complex within the cell walls. - **Alcohol/Acetone** is the **decolorizer**, washing out the primary stain from Gram-negative cells but not from Gram-positive cells. - Finally, **Safranin** is the **counterstain** that stains decolorized Gram-negative cells pink or red. *Iodine → Gentian violet → Alcohol/Acetone → Safranin* - **Iodine** is a mordant and needs a primary stain (like gentian violet) to bind to and form a complex; applying it first would not effectively stain the cells. - The correct sequence requires the primary stain to be applied before the mordant can fix it. *Safranin → Gentian violet → Iodine → Alcohol/Acetone* - **Safranin** is a counterstain and should be applied last to stain the decolorized Gram-negative cells, not as the first reagent. - Applying reagents out of order would lead to incorrect staining results, as **safranin** is meant to provide contrast after decolorization. *Gentian violet → Alcohol/Acetone → Iodine → Safranin* - **Alcohol/Acetone** (decolorizer) is applied too early in this sequence; it should be used after the mordant (iodine) has formed a complex with the primary stain. - Applying the decolorizer before the mordant would prevent the formation of the crystal violet-iodine complex, leading to incorrect differentiation between Gram-positive and Gram-negative bacteria.

Q: What is the recommended dosage for chloroquine chemoprophylaxis in malaria prevention?

500 mg once weekly. ***500 mg once weekly*** - The recommended dosage for chloroquine chemoprophylaxis in malaria prevention is **500 mg salt** (or equivalent to 300 mg base) administered **once weekly**. - This regimen ensures adequate blood concentrations to prevent malarial infection in endemic areas. *500 mg/week* - While the 500 mg dose is correct, simply stating "500 mg/week" without specifying "once weekly" could be misinterpreted. - Chloroquine is generally taken as a **single weekly dose**, not divided doses. *400 mg once weekly* - A dosage of **400 mg** is **sub-therapeutic** for weekly chloroquine chemoprophylaxis. - This dose would likely not provide sufficient protection against malaria. *500 mg BD/week* - Taking chloroquine **twice weekly (BD/week)** at 500 mg is excessive for chemoprophylaxis. - This regimen can lead to increased side effects and toxicity without providing additional prophylactic benefit.

Question 1

Which disease is most closely associated with intensive international surveillance for global eradication?

Accepted Answer

Polio

Answer

Hepatitis

Answer

TB

Answer

Leprosy

Question 2

Measles vaccination is given at -

Accepted Answer

9 months

Answer

At birth

Answer

4 weeks

Answer

8 weeks

Question 3

What are the serogroups covered by the bivalent meningococcal vaccine?

Accepted Answer

Serogroup A and C

Answer

Serogroup A

Answer

Serogroup W

Answer

Serogroup C

Question 4

Which is the main vector of Dengue?

Accepted Answer

A. aegypti

Answer

Culex

Answer

Anopheles

Answer

Aedes scutellaris

Question 5

Which of the following is a zoonotic disease?

Accepted Answer

Hydatid cyst

Answer

Malaria

Answer

Filariasis

Answer

Dengue fever

Question 6

Which of the following statements about the Late Expanding Phase of the Demographic Cycle is TRUE?

Accepted Answer

Death Rate declines more than Birth Rate

Answer

Death Rate becomes significantly lower than Birth Rate during this phase

Answer

Birth Rate remains consistently high while Death Rate starts to decline significantly

Answer

Birth Rate remains higher than Death Rate, leading to population growth

Question 7

What does the net reproduction rate indicate?

Accepted Answer

Average number of daughters a newborn girl will have during her lifetime

Answer

Number of live births per 1000 mid-year population

Answer

Number of live births per 1000 women of child bearing age

Answer

None of the options

Question 8

HIV post exposure prophylaxis should be started within?

Accepted Answer

72 hrs

Answer

1-2 hrs

Answer

14 hrs

Answer

18 hrs

Question 9

What is the correct order of application of reagents in the complete Gram staining procedure?

Accepted Answer

Gentian violet → Iodine → Alcohol/Acetone → Safranin

Answer

Iodine → Gentian violet → Alcohol/Acetone → Safranin

Answer

Safranin → Gentian violet → Iodine → Alcohol/Acetone

Answer

Gentian violet → Alcohol/Acetone → Iodine → Safranin

Question 10

What is the recommended dosage for chloroquine chemoprophylaxis in malaria prevention?

Accepted Answer

500 mg once weekly

Answer

500 mg/week

Answer

400 mg once weekly

Answer

500 mg BD/week

NEET-PG 2012

Community Medicine

Internal Medicine

Microbiology

Pharmacology