Which of the following vaccines is not typically given in disaster situations?
In the context of disease screening, which type of lead time is most beneficial for effective screening?
What is the annual infection rate of tuberculosis?
According to the immunization schedule, how many doses of influenza vaccine should children under 9 years of age receiving the vaccine for the first time typically receive?
Which of the following diseases is classified under category-B of bioterrorism?
Most common mode of transmission of nosocomial infection is -
Infant mortality rate in India is per 1000 live births?
Infectivity period of chickenpox is ?
Pearl's index is defined as the number of unintended pregnancies per:
Which of the following is NOT a criterion for defining a polio epidemic?
NEET-PG 2013 - Community Medicine NEET-PG Practice Questions and MCQs
Question 21: Which of the following vaccines is not typically given in disaster situations?
- A. Influenza (Correct Answer)
- B. Measles
- C. Cholera
- D. Tetanus
Explanation: ***Influenza*** - **Influenza vaccination** is generally **NOT a priority** in acute disaster response and emergency vaccination campaigns. - While influenza can spread in crowded conditions, routine disaster response protocols focus on **immediately life-threatening and epidemic-prone diseases** rather than seasonal respiratory infections. - Influenza vaccination requires **cold chain maintenance** and repeated doses, making it logistically challenging in emergency settings. - WHO and SPHERE guidelines do not list influenza among priority vaccines for disaster situations unless there is a specific ongoing outbreak. *Cholera* - **Oral cholera vaccine (OCV)** is increasingly recommended by WHO for disaster settings with **high cholera risk**, particularly in areas with poor water and sanitation. - Modern OCVs (like Shanchol and Euvichol) have improved **cost-effectiveness** and logistics, making them viable for mass campaigns. - Used in conjunction with **WASH interventions** (water, sanitation, hygiene) for comprehensive cholera control. *Measles* - **Measles vaccination** is the **highest priority** vaccine in disaster response, particularly for children aged 6 months to 15 years. - Its **extreme contagiousness** (R0 = 12-18) and high mortality in malnourished populations make it critical. - WHO recommends measles vaccination within the **first days** of a disaster response in displacement settings. *Tetanus* - **Tetanus toxoid** (often as Td or DT) is essential in disasters involving injuries, floods, earthquakes, or debris. - Protects against **_Clostridium tetani_** infection from contaminated wounds. - Part of standard **wound management protocols** in emergency medical care.
Question 22: In the context of disease screening, which type of lead time is most beneficial for effective screening?
- A. Short lead time
- B. Both short and long lead times are beneficial
- C. Long lead time is beneficial for screening (Correct Answer)
- D. Lead time has no impact on screening effectiveness
Explanation: ***Long lead time is beneficial for screening*** - **Long lead time** provides a greater window of opportunity between disease detection by screening and clinical symptom onset - This extended asymptomatic detectable phase allows for **early intervention** when treatments are most effective - Longer lead time correlates with improved prognosis and potential prevention of severe outcomes - Essential criterion for effective screening programs per **Wilson-Jungner criteria** *Short lead time* - Limited time between disease detectability and clinical symptoms - Reduces screening effectiveness as disease progresses rapidly - Minimal opportunity for beneficial early intervention *Both short and long lead times are beneficial* - Only **long lead time** is beneficial for screening programs - Short lead time actually limits screening effectiveness - Screening benefit is directly proportional to duration of asymptomatic detectable phase *Lead time has no impact on screening effectiveness* - **Lead time is crucial** for determining screening program effectiveness - Directly impacts the window for early detection and intervention - Without adequate lead time, screening loses its preventive value
Question 23: What is the annual infection rate of tuberculosis?
- A. Percentage of total patients positive for tuberculin test
- B. Percentage of new patients positive for tuberculin test (Correct Answer)
- C. Percentage of sputum positive total patients
- D. Percentage of sputum positive new patients
Explanation: ***Percentage of new patients positive for tuberculin test*** - The **annual infection rate of tuberculosis (AIRT)** is defined as the percentage of individuals (typically children aged 1-9 years) who show **tuberculin conversion** (from negative to positive) in a given year. - Among the given options, this is the **closest representation** as it focuses on **newly infected individuals** rather than prevalent cases. - AIRT is a key epidemiological indicator reflecting **ongoing transmission** and the **annual risk of tuberculous infection** in a community. - This measure helps assess TB control program effectiveness and disease burden. *Percentage of total patients positive for tuberculin test* - This represents the **prevalence of tuberculosis infection** in the population, including both old and new infections. - It does not specifically measure the **annual rate of acquiring new infections**, which is what AIRT captures. *Percentage of sputum positive total patients* - This indicates the **prevalence of active, infectious pulmonary tuberculosis** in a population. - It refers to individuals with **active TB disease** who are shedding bacteria in sputum, not latent infection detected by tuberculin testing. *Percentage of sputum positive new patients* - This represents the **incidence of new, active, infectious tuberculosis cases** (case detection rate). - While important for TB surveillance, it measures **active disease** rather than **infection rate** detected by tuberculin skin test.
Question 24: According to the immunization schedule, how many doses of influenza vaccine should children under 9 years of age receiving the vaccine for the first time typically receive?
- A. 2 doses at 4 weeks interval with a booster dose for high-risk children
- B. 2 doses at 4 weeks interval (Correct Answer)
- C. 3 doses at 4 weeks interval
- D. None of the options
Explanation: ***2 doses at 4 weeks interval*** - Children **under 9 years of age** receiving the influenza vaccine for the **first time** require **two doses** administered at least **4 weeks (28 days) apart**. - This two-dose priming schedule is essential to ensure adequate immune response and protection against circulating influenza strains. - This recommendation is consistent across **IAP (Indian Academy of Pediatrics)** and **CDC guidelines**. - Children 9 years and older, and younger children who have been previously vaccinated, require only **1 dose annually**. *3 doses at 4 weeks interval* - The standard protocol for influenza vaccination does **not involve three doses**. - A three-dose schedule is typically seen with vaccines like **Hepatitis B**, **DTaP**, or **Hib**, but not for influenza. *2 doses at 4 weeks interval with a booster dose for high-risk children* - While high-risk children (chronic lung disease, heart disease, immunocompromised) are priority groups for influenza vaccination, the schedule remains **two initial doses** for first-time recipients under 9 years. - There is **no additional booster dose** beyond the two-dose series within the same influenza season, even for high-risk children. - Subsequent years require only **1 dose annually**. *None of the options* - This is incorrect as the standard recommendation is clearly established in immunization guidelines. - The **two-dose schedule at 4-week intervals** for first-time recipients under 9 years is well-documented by IAP and international guidelines.
Question 25: Which of the following diseases is classified under category-B of bioterrorism?
- A. Anthrax
- B. Plague
- C. Botulism
- D. Cholera (Correct Answer)
Explanation: ***Cholera*** - **Cholera** is classified under **Category B** agents due to its moderate ease of dissemination, moderate morbidity rates, and low mortality rates. - While it can cause severe diarrheal disease, its treatment is relatively straightforward with **rehydration therapy**, and it poses a lower risk of mass casualties compared to Category A agents. *Anthrax* - **Anthrax** is a **Category A** bioterrorism agent, characterized by its high mortality rate, ease of dissemination, and potential for major public health impact. - It poses a significant threat due to its ability to form **spores** that are highly resistant and can cause severe lung infection. *Plague* - **Plague** is designated as a **Category A** agent because of its high potential for mass dissemination, high mortality if untreated, and potential to cause widespread panic. - It can be spread via **aerosols** and can lead to severe systemic illness. *Botulism* - **Botulism** is classified as a **Category A** agent due to the extreme potency of the **botulinum toxin**, even in minute quantities, which can cause severe flaccid paralysis and death. - It has a high potential for causing severe public health impact and requires complex medical interventions.
Question 26: Most common mode of transmission of nosocomial infection is -
- A. Hand contact (Correct Answer)
- B. Droplet infection
- C. Blood and blood products
- D. Contaminated water
Explanation: ***Hand contact*** - **Direct contact** with healthcare workers' contaminated hands is the primary way pathogens are transferred between patients in a healthcare setting. - Failure to perform adequate **hand hygiene** between patient contacts is the single most important factor contributing to nosocomial infection transmission. *Droplet infection* - While droplet transmission can cause nosocomial infections, especially for respiratory viruses, it is not the most common mode of transmission for the overall burden of healthcare-associated infections. - **Droplets** usually travel short distances and deposit on mucous membranes of the nose, mouth, or eyes of a susceptible host. *Blood and blood products* - Transmission through **blood and blood products** is a significant concern for specific infections (e.g., HIV, hepatitis B/C), but the incidence is relatively low due to stringent screening and safety protocols. - This mode accounts for a small fraction of overall nosocomial infections compared to contact transmission. *Contaminated water* - **Contaminated water** can lead to outbreaks (e.g., *Legionella*, *Pseudomonas*), especially in immunocompromised patients, but it is not the most frequent mode of transmission on a day-to-day basis across all types of nosocomial infections. - Healthcare facilities implement measures to ensure water safety, limiting this as the primary route.
Question 27: Infant mortality rate in India is per 1000 live births?
- A. 25
- B. 55
- C. 60
- D. 34 (Correct Answer)
Explanation: ***34*** - As per the **Sample Registration System (SRS)** data around **2012-2013**, India's **Infant Mortality Rate (IMR)** was reported as **34 deaths per 1,000 live births**. - This represents the number of infant deaths (before completing one year of age) per 1,000 live births in a given year. - This was the approximate national average used for the NEET-2013 examination period. *25* - This figure represents a lower IMR than the national average for India during 2012-2013. - While some progressive states like Kerala had achieved IMR closer to this figure, it was not the overall national rate at that time. *55* - This figure is higher than the reported national IMR for India in 2012-2013. - India's IMR had already declined below this level due to improved maternal and child health programs under NRHM (National Rural Health Mission). *60* - This value represents a historical estimate from earlier years (pre-2010). - By 2012-2013, India had made significant progress in reducing infant mortality from these higher historical levels through better healthcare access and immunization coverage.
Question 28: Infectivity period of chickenpox is ?
- A. 1 day before and 4 days after appearance of rash (Correct Answer)
- B. Only when scab falls
- C. Entire incubation period
- D. 4 days before and 5 days after appearance of rash
Explanation: ***1 day before and 4 days after appearance of rash*** - The infectivity period of **chickenpox (varicella)** begins approximately **1-2 days (24-48 hours) before the rash appears**. - It extends until **all lesions have crusted over**, which typically occurs around **5-6 days after rash onset**, though some sources cite **4-5 days**. - This option represents the **commonly accepted timeframe** taught in Indian medical curricula and NEET PG examinations. *4 days before and 5 days after appearance of rash* - The **pre-rash infectivity period is too long** in this option; chickenpox is infectious for only **1-2 days before rash**, not 4 days. - While the "5 days after" is medically accurate, the incorrect pre-rash duration makes this option wrong. *Only when scab falls* - This statement is **incorrect**; infectivity starts much earlier, **1-2 days before the rash appears**. - By the time scabs fall, the person is **no longer infectious**, as crusted lesions contain non-infectious material. - This option ignores the critical **pre-rash and early rash infectious period**. *Entire incubation period* - The **incubation period** for chickenpox is usually **10-21 days**, during which the individual is **not infectious** for most of this time. - Infectivity begins only in the **last 1-2 days of incubation** (just before rash onset) and continues into the eruptive phase, not for the entire duration.
Question 29: Pearl's index is defined as the number of unintended pregnancies per:
- A. Per 100 woman years (Correct Answer)
- B. Per 10 woman years
- C. Per 1000 woman years
- D. Per 50 woman years
Explanation: ***Per 100 woman years*** - The **Pearl Index** is a common measure of the effectiveness of contraception. - It is calculated as the number of unintended pregnancies per **100 woman-years** of exposure to a contraceptive method. *Per 10 woman years* - This metric represents too small a population and duration to provide a statistically reliable measure of contraceptive effectiveness. - Using 10 woman-years as the denominator would inappropriately inflate the Pearl Index value, making methods appear less effective than they are. *Per 1000 woman years* - While a larger denominator provides greater statistical power, the standard definition of the Pearl Index specifically uses **100 woman-years**. - Expressing it per 1000 woman-years would make the index numerically smaller, potentially leading to misinterpretation if not clearly stated. *Per 50 woman years* - This denominator is not the standard convention for calculating the **Pearl Index**. - It would result in a different numerical value for the index, making direct comparisons with commonly reported Pearl Index values challenging.
Question 30: Which of the following is NOT a criterion for defining a polio epidemic?
- A. Caused by same virus type
- B. Cases should occur in same locality
- C. 2 or more cases
- D. Cases occurring during a 6 month period (Correct Answer)
Explanation: ***Correct: Cases occurring during a 6 month period*** - The definition of a polio epidemic primarily focuses on criteria like the number of cases, their geographical proximity, and the viral serotype causing the infection, not a specific duration of time over which cases occur. - While an outbreak naturally unfolds over a period, a fixed 6-month window is **not a formal defining criterion** for an epidemic, which typically emphasizes a sudden, significant increase above expected levels. *Incorrect: 2 or more cases* - An epidemic is generally defined by an **unusual increase in disease incidence**, and even two confirmed cases, especially in areas with low endemicity or where polio is eradicated, can signal an outbreak. - The presence of **two or more paralytic polio cases** within a specific area is often considered a critical threshold for declaring an epidemic, particularly for **wild poliovirus**. *Incorrect: Cases should occur in same locality* - For an epidemic to be declared, the cases must be **geographically linked** to indicate a common source or local transmission. - Cases spread across different, unconnected regions would suggest **sporadic occurrences** rather than a localized epidemic. *Incorrect: Caused by same virus type* - An epidemic implies a **common etiologic agent**, meaning the cases should be linked to the same serotype of **poliovirus** (e.g., wild poliovirus type 1). - If cases are caused by different serotypes, it indicates **multiple independent introductions** rather than a single epidemic outbreak.