NEET-PG 2012 Practice Questions

Q: Following are examples of human "dead end" diseases except -

Bubonic plague. ***Bubonic plague (Plague)*** - The question refers to **plague in general**, which includes multiple clinical forms. - While **bubonic plague** (the most common form) is transmitted via **flea bites** from infected rodents and humans are typically dead-end hosts for this form, **pneumonic plague** (secondary complication or primary infection) allows **human-to-human transmission** via respiratory droplets. - This makes plague the **exception** among the listed diseases, as humans can serve as a source of infection to others in the pneumonic form, unlike true dead-end host situations. *Japanese encephalitis* - Humans are **dead-end hosts** for Japanese encephalitis virus. - Infected humans do not develop sufficient **viremia** to infect feeding mosquitoes. - The virus maintains its cycle between **Culex mosquitoes**, **pigs** (amplifying hosts), and **wading birds**, with humans being incidental hosts. *Hydatid disease* - Humans are **definitive dead-end hosts** for *Echinococcus granulosus* (causing cystic echinococcosis/hydatid disease). - The normal life cycle requires **definitive hosts** (dogs, canids) and **intermediate hosts** (sheep, cattle). - Humans develop **hydatid cysts** but cannot transmit the infection further as the parasite cannot complete its life cycle in humans. *Leishmaniasis* - In most forms of leishmaniasis, humans are considered **dead-end or accidental hosts**, particularly in **zoonotic cutaneous leishmaniasis** where animal reservoirs (rodents, dogs) maintain transmission. - However, in **anthroponotic visceral leishmaniasis** (*Leishmania donovani* in the Indian subcontinent), humans can serve as reservoir hosts. - For the purpose of this question, leishmaniasis is generally classified with dead-end diseases as the majority of leishmaniasis forms have zoonotic cycles where humans are incidental hosts with limited onward transmission.

Q: Which disease is associated with a propagative cycle?

Filaria. ***Filaria*** - The **filarial worm** undergoes a **biological transmission cycle** in the mosquito vector where microfilariae develop through larval stages (L1 → L2 → L3) with multiplication. - This represents a **cyclopropagative cycle** (both development and multiplication occur in the vector). - In the context of this question and classical teaching, filaria is considered the standard example of biological transmission with vector multiplication. - The infective L3 larvae multiply from a single microfilaria, and multiple larvae can develop within one mosquito. *Plague* - **Plague** (*Yersinia pestis*) is transmitted by fleas through **mechanical transmission**. - Bacteria multiply in the flea's gut causing blockage (blocking transmission), but this is not considered a true biological cycle. - The pathogen does not undergo developmental stages in the vector. *Malaria* - **Malaria** (*Plasmodium* spp.) undergoes the **sporogonic cycle** in the mosquito, which is also a **cyclopropagative cycle**. - Gametocytes → ookinete → oocyst → sporozoites (development with multiplication). - While biologically similar to filaria, in classical epidemiology teaching, filaria is more commonly cited as the example for propagative transmission. *None of the options* - This option is incorrect as filaria demonstrates biological transmission with multiplication in the vector. - Both filaria and malaria technically undergo cyclopropagative cycles, but filaria is the conventional answer in medical education contexts.

Q: What is the minimum percentage of the population that needs to be vaccinated to eradicate measles?

95%. **95%** - Measles is highly contagious, requiring a **high percentage of immunity** in the population to establish **herd immunity** and prevent outbreaks. - A **95% vaccination coverage** ensures that enough individuals are protected, breaking the chain of transmission and leading to potential eradication. *85%* - This percentage is **insufficient** for highly transmissible diseases like measles. - An 85% vaccination rate would still leave a significant portion of the population susceptible, allowing measles to **continue circulating** and causing outbreaks. *70%* - This level of vaccination is **far too low** for measles, which has a basic reproduction number (R0) of 12-18. - A 70% coverage would result in frequent and widespread measles outbreaks due to **inadequate herd immunity**. *80%* - While 80% vaccination offers some protection, it is still **below the threshold** needed for measles eradication. - Measles outbreaks can still occur with an 80% coverage, particularly in populations with **non-uniform distribution of immunity**.

Q: What is the standard amount of diphtheria toxoid in the DT vaccine?

30 Lf. ***30 Lf*** - The **DT vaccine** (pediatric diphtheria-tetanus vaccine) contains **30 Lf** of **diphtheria toxoid** per dose according to traditional formulations, along with tetanus toxoid. - This higher diphtheria toxoid content is standardized for vaccines administered to children younger than 7 years. - Note: Modern vaccine standards often express potency in **International Units (IU)** where ≥30 IU corresponds to approximately 15-25 Lf, though 30 Lf was the traditional specification. *5 Lf* - This reduced amount of diphtheria toxoid is present in adult formulations like **Tdap vaccine** and **Td vaccine** (typically 2-5 Lf). - The lower diphtheria toxoid content in adult vaccines is sufficient to maintain immunity in individuals with pre-existing immunity from childhood vaccination. *10 Lf* - This amount of diphtheria toxoid is not a standard specification for DT, Td, or Tdap vaccines. - Standard diphtheria toxoid amounts are typically 15-30 Lf for pediatric formulations (DT/DTP) and 2-5 Lf for adult formulations (Td, Tdap). *15 Lf* - While approximately 15 Lf may correspond to the minimum potency when measured in International Units (≥30 IU), the traditional standard specification for DT vaccine is **30 Lf**. - Vaccine formulations are precisely standardized to ensure optimal immunogenicity and safety.

Q: What is the most commonly reported bacterial sexually transmitted infection?

Chlamydia. ***Correct: Chlamydia*** - **Chlamydia trachomatis** is the most frequently reported bacterial STI in many countries, often being **asymptomatic** and thus easily spread - Its high prevalence is due to efficient transmission and the widespread use of sensitive diagnostic tests that detect infections in asymptomatic individuals - Accounts for the majority of reported bacterial STI cases globally *Incorrect: HSV* - **Herpes Simplex Virus (HSV)** is a **viral STI**, not bacterial, and is characterized by recurrent outbreaks of **genital ulcers** or sores - While common, it does not qualify as a bacterial infection and is often not laboratory-confirmed due to mild or subclinical presentations *Incorrect: HIV* - **Human Immunodeficiency Virus (HIV)** is also a **viral STI**, not bacterial, that attacks the immune system leading to AIDS - Although highly impactful, HIV is not a bacterial infection and has lower incidence rates compared to Chlamydia *Incorrect: Syphilis* - **Syphilis**, caused by the bacterium **Treponema pallidum**, is a serious bacterial STI that can have long-term complications if untreated - While its incidence has been increasing in some regions, it is significantly less common than **Chlamydia** in terms of overall reported cases

Q: Which organization among the following is specifically mandated to work on reproductive health and family planning globally?

UNFPA. ***UNFPA*** - The **United Nations Population Fund (UNFPA)** is the lead UN agency for delivering a world where every pregnancy is wanted, every birth is safe, and every young person's potential is fulfilled. - Its mandate specifically focuses on **sexual and reproductive health (SRH)**, family planning, and maternal health worldwide. *UNICEF* - The **United Nations Children's Fund (UNICEF)** focuses on providing humanitarian and developmental aid to children worldwide, prioritizing their health, education, and protection. - While it addresses child health, its primary mandate is not exclusive to reproductive health or family planning. *ILO* - The **International Labour Organization (ILO)** is a United Nations agency whose mandate is to advance social and economic justice by establishing international labor standards. - Its work focuses on labor rights, decent work, and social protection, not reproductive health. *WHO* - The **World Health Organization (WHO)** works broadly on all aspects of global health including infectious diseases, non-communicable diseases, health systems, and emergency response. - While WHO does work on reproductive health, it is not specifically mandated exclusively for reproductive health and family planning like UNFPA.

Q: What is the most common method of family planning sterilization practiced in India?

Female sterilization. ***Female sterilization*** - **Female sterilization** (tubal ligation) is the most prevalent method of permanent contraception in India, accounting for over **95% of all sterilization procedures**. - This is primarily due to historical policies focusing on female methods and various **socio-cultural factors** including gender norms and male reluctance. - According to **NFHS data**, female sterilization is the single most common contraceptive method overall in India. *Male sterilization* - **Male sterilization** (vasectomy) is significantly less common compared to female sterilization in India, accounting for less than 5% of sterilization procedures. - This disparity is attributed to **gender norms**, misconceptions about masculinity, and limited promotion of vasectomy services. *Condom use* - While condoms are a common **temporary contraceptive method**, the question specifically asks about **sterilization methods**, which are permanent. - Condoms are barrier methods, not sterilization procedures. *Intrauterine device (IUD)* - IUDs are **reversible long-acting contraceptive methods**, not sterilization procedures. - Though IUDs are increasingly popular in India, they do not constitute a sterilization method as they can be removed.

Q: Which type of vaccine is used for chicken pox?

Live vaccine. ***Live vaccine*** - The chickenpox vaccine (Varicella vaccine) is a **live-attenuated vaccine**, meaning it contains a weakened form of the **Varicella-zoster virus** (Oka strain). - This weakened virus can still replicate in the body, stimulating a strong and long-lasting immune response similar to natural infection but without causing severe disease. *Killed vaccine* - **Killed (inactivated) vaccines** use viruses or bacteria that have been inactivated through heat or chemicals, making them unable to replicate. - While effective for some diseases (e.g., inactivated polio, influenza), they typically require **multiple doses** and might provide less durable immunity compared to live vaccines. *Conjugated vaccine* - **Conjugated vaccines** are designed to improve the immune response to polysaccharide antigens (e.g., bacterial capsules) by linking them to a carrier protein. - This technology is primarily used for **bacterial infections** like *Haemophilus influenzae* type b (Hib) or pneumococcal disease, not viral illnesses like chickenpox. *Toxoid vaccine* - **Toxoid vaccines** contain inactivated bacterial toxins (toxoids) rather than the whole organism. - Examples include **tetanus and diphtheria vaccines**, which protect against diseases caused by bacterial toxins, not viral infections like chickenpox.

Q: In which period is maternal mortality highest?

Peripartum. ***Peripartum*** - The peripartum period encompasses the time immediately before, during, and after childbirth, when the risks of **hemorrhage, infection, pre-eclampsia/eclampsia**, and other **acute obstetric complications** are highest. - The **physiological stresses** of labor and delivery, coupled with potential complications like **uterine atony** or **obstructed labor**, contribute significantly to maternal mortality during this critical window [2]. *Antepartum* - While complications like **severe pre-eclampsia, ectopic pregnancy**, and chronic conditions can occur during the antepartum period, the **acute risks of hemorrhage and infection** are generally lower than during and immediately after delivery [1]. - Most maternal deaths occurring antepartum are due to conditions that ultimately lead to or manifest more severely during the peripartum or postpartum phases, such as undetected pre-eclampsia worsening to eclampsia [3]. *Postpartum* - The postpartum period (especially the first 42 days) also carries significant risks such as **late postpartum hemorrhage, puerperal sepsis, and thromboembolism** [2]. - While substantial, the **magnitude of mortality risk** primarily due to acute events related to labor and delivery (e.g., massive hemorrhage, amniotic fluid embolism) is often concentrated in the peripartum period [2]. *No period of maximum risk* - This statement is incorrect because maternal mortality risk is demonstrably **higher during specific periods** related to pregnancy and childbirth, rather than being evenly distributed [1]. - The physiological changes and obstetric challenges associated with gestation, labor, and the puerperium create distinct periods of elevated risk for maternal morbidity and mortality.

Q: What does colostrum have compared to normal milk?

Increased proteins. ***Increased proteins*** - **Colostrum** is rich in **immunoglobulins (antibodies)** like IgA, IgG, and IgM, which are proteins crucial for passive immunity in the newborn, making its protein content **2-3 times higher** than mature milk (approximately 2.3 g/100 mL vs 0.9 g/100 mL). - These high protein levels also include **lactoferrin** and **growth factors**, which support the development of the infant's gut and immune system. - This is the **most clinically significant** distinguishing feature of colostrum. *Decreased potassium* - **Potassium (K)** levels in colostrum are actually **similar to or slightly higher** than mature milk (approximately 74 mg/100 mL vs 51 mg/100 mL). - This option is incorrect as potassium is not decreased. *Decreased sodium* - **Sodium (Na)** levels are actually **significantly higher** in colostrum than in mature milk (approximately 48 mg/100 mL vs 15 mg/100 mL). - This elevated sodium gives colostrum a distinct salty taste, differentiating it from mature milk. - This option is incorrect as sodium is increased, not decreased. *Decreased calories* - While colostrum has a **lower fat content** than mature milk, leading to somewhat lower caloric density (54-58 kcal/100 mL vs 65-70 kcal/100 mL), this is not the primary distinguishing characteristic. - The most important feature of colostrum is its **high protein and immunoglobulin content** for immune protection, not its caloric value.

Question 1

Following are examples of human "dead end" diseases except -

Accepted Answer

Bubonic plague

Answer

Hydatid disease

Answer

Japanese encephalitis

Answer

Leishmaniasis

Question 2

Which disease is associated with a propagative cycle?

Accepted Answer

Filaria

Answer

None of the options

Answer

Plague

Answer

Malaria

Question 3

What is the minimum percentage of the population that needs to be vaccinated to eradicate measles?

Accepted Answer

95%

Answer

85%

Answer

70%

Answer

80%

Question 4

What is the standard amount of diphtheria toxoid in the DT vaccine?

Accepted Answer

30 Lf

Answer

5 Lf

Answer

10 Lf

Answer

15 Lf

Question 5

What is the most commonly reported bacterial sexually transmitted infection?

Accepted Answer

Chlamydia

Answer

HSV

Answer

HIV

Answer

Syphilis

Question 6

Which organization among the following is specifically mandated to work on reproductive health and family planning globally?

Accepted Answer

UNFPA

Answer

UNICEF

Answer

ILO

Answer

WHO

Question 7

What is the most common method of family planning sterilization practiced in India?

Accepted Answer

Female sterilization

Answer

Male sterilization

Answer

Intrauterine device (IUD)

Answer

Condom use

Question 8

Which type of vaccine is used for chicken pox?

Accepted Answer

Live vaccine

Answer

Killed vaccine

Answer

Conjugated vaccine

Answer

Toxoid vaccine

Question 9

In which period is maternal mortality highest?

Accepted Answer

Peripartum

Answer

Antepartum

Answer

Postpartum

Answer

No period of maximum risk

Question 10

What does colostrum have compared to normal milk?

Accepted Answer

Increased proteins

Answer

Decreased potassium

Answer

Decreased sodium

Answer

Decreased calories

NEET-PG 2012

Community Medicine

Microbiology

Obstetrics and Gynecology

Physiology