NEET-PG 2013 - Community Medicine Practice Questions

Q: Which of the following is NOT a criterion for defining a polio epidemic?

Cases occurring during a 6 month period. ***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.

Q: In typhoid, a person is considered a permanent carrier if they excrete bacilli for more than how many months?

1 year. **1 year** - A person is defined as a permanent carrier of typhoid if they excrete **Salmonella Typhi** in their feces or urine for **more than one year** after the acute illness. - This long-term excretion is often associated with chronic infection of the **gallbladder**, particularly in individuals with gallstones. - The definition of chronic/permanent carrier status is set at **≥12 months** of continuous bacillary excretion. *3 months* - Excreting bacilli for 3 months after acute typhoid is considered a **convalescent carrier state**, not a permanent one. - Many individuals clear the infection within this timeframe without becoming chronic carriers. *6 months* - While prolonged, 6 months of excretion still falls under the definition of a **convalescent or temporary carrier**, rather than a permanent carrier. - The threshold for "permanent" or "chronic" carrier status is typically set at 12 months. *3 years* - While a person excreting bacilli for 3 years would certainly be a permanent carrier, the established definition for permanent carrier status is met at **1 year**, not 3 years. - This option represents an unnecessarily longer duration than the standard definition.

Q: Malaria is transmitted in Rural areas by?

Anopheles culicifacies. ***Anopheles culicifacies*** - **_Anopheles culicifacies_** is the **primary vector of malaria in rural areas of India** and is also found in Southeast Asia. - Its breeding habitats often include **rice fields, irrigation channels, and temporary water collections** common in rural agricultural settings. - It accounts for a major proportion of rural malaria transmission in the Indian subcontinent. *Anopheles stephensi* - **_Anopheles stephensi_** is a significant malaria vector primarily found in **urban and semi-urban areas**, including parts of the Middle East, India, and Iran. - Its preferred breeding sites are **artificial containers found in urban environments**, such as water storage tanks, overhead tanks, and cisterns. *Anopheles dirus* - **_Anopheles dirus_** is a dominant malaria vector in **forested and hilly regions of Southeast Asia**, often associated with forest malaria. - It's known for outdoor feeding behavior and maintaining transmission in relatively undisturbed natural environments. *None of the options* - This option is incorrect because **_Anopheles culicifacies_** is a well-established and significant vector for malaria in rural areas of India. - Identification of a specific primary vector for rural transmission makes this choice invalid.

Q: What is the most common Anopheles mosquito responsible for malaria in India?

Anopheles culicifacies. ***Anopheles culicifacies*** - This species is the **most common and primary malaria vector in India**, responsible for approximately 60-70% of all malaria transmission in the country. - It is the **major rural vector** of malaria, especially in agricultural areas, and transmits both *Plasmodium vivax* and *P. falciparum*. - Given that the majority of India's population resides in rural areas where malaria burden is highest, *A. culicifacies* is the most important vector overall. *Anopheles stephensi* - This species is recognized as the **primary urban vector** of malaria in India, particularly for *P. vivax* and *P. falciparum*. - Its ability to breed in artificial containers makes it well-adapted to urban environments, but it accounts for a smaller proportion of total malaria cases compared to *A. culicifacies*. *Anopheles fluviatilis* - This species is an **important vector in hilly and forest areas** of India, rather than being the most common overall. - It is known to transmit both *P. vivax* and *P. falciparum* in these specific ecological niches. *Anopheles subpictus* - While present in India, *A. subpictus* is generally considered a **poor vector** of malaria due to its low susceptibility to Plasmodium infection. - It mainly breeds in diverse habitats including paddy fields and brackish water.

Q: Which indicator best measures the operational efficiency of a malaria control programme?

Annual blood examination rate. ***Annual blood examination rate*** - The **Annual Blood Examination Rate (ABER)** directly reflects the proportion of the population that has been tested for malaria, indicating the reach and effectiveness of surveillance activities. - A high ABER suggests that active case detection and diagnosis are being effectively implemented, which is crucial for operational efficiency in identifying and managing cases. *Infant parasite rate* - The **infant parasite rate** measures the prevalence of malaria infection among infants, serving as an indicator of recent transmission intensity. - While important for assessing disease burden and transmission, it doesn't directly measure the operational effectiveness of interventions like testing or treatment programs. *Slide positivity rate* - The **slide positivity rate (SPR)** is the proportion of positive malaria slides among all slides examined, indicating the likelihood of an individual seeking testing to actually have malaria. - While SPR helps understand disease activity among tested individuals, it doesn't reflect the full operational reach of a program in the general population or the overall testing effort. *Mosquito bite rate* - The **mosquito bite rate** measures the number of mosquito bites per person per night, indicating the level of human exposure to malaria vectors. - This is an entomological indicator of transmission risk and the impact of vector control, but it does not directly assess the operational efficiency of human-centric interventions like diagnosis and treatment programs.

Q: The international quarantine period for yellow fever as approved by the Government of India is ?

6 days. ***6 days*** - The **incubation period** for yellow fever is typically 3-6 days, and the 6-day quarantine period is internationally accepted to cover this range. - This period is established to prevent the importation and spread of the disease by ensuring that individuals arriving from endemic areas do not develop symptoms after arrival. *9 days* - This duration is **longer than the internationally recognized incubation period** for yellow fever and is not the standard quarantine period. - Implementing a 9-day quarantine would be excessive and not based on the typical disease progression. *10 days* - A 10-day quarantine period is also **not the standard** for yellow fever as approved by international health regulations or by the Government of India. - While some diseases may require a 10-day quarantine, yellow fever's incubation period makes 6 days sufficient. *12 days* - A 12-day quarantine is **significantly longer** than necessary for yellow fever, as virtually all cases would manifest symptoms within the first 6 days. - This period is typically associated with diseases with much longer incubation periods, which is not the case for yellow fever.

Q: Based on the type of life cycle, zoonoses are classified into all of the following except -

Anthropozoonoses. ***Anthropozoonoses*** - This is **NOT a life cycle-based classification** of zoonoses. - It describes the **direction of transmission** (animals to humans), not the complexity or types of hosts required in the parasite's life cycle. - While a valid classification of zoonoses, it is based on **transmission pattern**, not life cycle characteristics. *Cyclo-zoonoses* - These are zoonoses that require **more than one vertebrate host species** to complete their life cycle, but **no invertebrate host** is involved. - This IS a life cycle-based classification. - Examples include **taeniasis** (tapeworm infections) where the parasite cycles between humans and livestock. *Meta-zoonoses* - These zoonoses require **both vertebrate and invertebrate hosts** to complete their life cycle. - This IS a life cycle-based classification. - The **invertebrate host** acts as an essential part of the life cycle for maturation or multiplication of the pathogen (e.g., **arboviruses** transmitted by mosquitoes, **plague** via fleas). *Sporozoonoses* - While this term is **not part of the standard WHO classification** of zoonoses by life cycle, the prefix "sporo-" refers to **spore-forming stages** in parasitic life cycles. - The standard WHO classification includes: **Orthozoonoses** (direct), **Cyclozoonoses**, **Metazoonoses**, and **Saprozoonoses** (requiring inanimate environment). - However, this term relates to life cycle characteristics (spore stages), not transmission direction.

Q: All of the following are anthropozoonosis except

Schistosomiasis. ***Schistosomiasis*** - This is a **human-to-human** disease, even though it involves an intermediate **snail host**. - Its life cycle does not involve transmission of pathogens from vertebrate animals to humans. *Rabies* - Rabies is a classic **anthropozoonosis**, transmitted to humans primarily through the saliva of infected animals, most commonly **dogs** and **bats**. - It involves a pathogen (rabies virus) that cycles between animals and can be transmitted to humans. *Plague* - Plague is an **anthropozoonosis** caused by *Yersinia pestis*, typically transmitted from **rodents** (e.g., rats) to humans via flea bites. - The disease maintains a natural reservoir in wild rodent populations, making it a prime example of animal-to-human transmission. *Anthrax* - Anthrax is an **anthropozoonosis** caused by *Bacillus anthracis*, transmitted to humans from infected **livestock** (e.g., cattle, sheep). - Humans usually acquire the infection through contact with infected animals or their products, or by inhaling spores.

Q: To achieve neonatal tetanus elimination, the incidence of neonatal tetanus per 1000 live births should be reduced to less than:

1.0. ***1.0*** - The international target for **neonatal tetanus elimination (NTE)** as defined by WHO/UNICEF is an incidence rate of **less than 1 case per 1,000 live births per year** in every district of a country. - This is the globally recognized threshold for declaring that neonatal tetanus has been eliminated as a public health problem. - Countries achieving this target at the district level are considered to have achieved NTE. *0.1* - While 0.1 per 1,000 live births represents an extremely low incidence, this is not the WHO-defined threshold for **neonatal tetanus elimination**. - The elimination target is less stringent at <1 per 1,000 live births, making disease control achievable while still representing a major public health success. *0.2* - An incidence of 0.2 per 1,000 live births, though very low, is not the internationally recognized threshold for **neonatal tetanus elimination**. - The established WHO/UNICEF target is <1 per 1,000 live births in every district. *0.5* - An incidence of 0.5 per 1,000 live births indicates excellent control of neonatal tetanus but is not the specific cut-off value. - The WHO criterion for elimination is less than 1 case per 1,000 live births per year at the district level.

Question 1

Which of the following is NOT a criterion for defining a polio epidemic?

Accepted Answer

Cases occurring during a 6 month period

Answer

Caused by same virus type

Answer

Cases should occur in same locality

Answer

2 or more cases

Question 2

In typhoid, a person is considered a permanent carrier if they excrete bacilli for more than how many months?

Accepted Answer

1 year

Answer

3 months

Answer

6 months

Answer

3 years

Question 3

Malaria is transmitted in Rural areas by?

Accepted Answer

Anopheles culicifacies

Answer

Anopheles stephensi

Answer

Anopheles dirus

Answer

None of the options

Question 4

What is the most common Anopheles mosquito responsible for malaria in India?

Accepted Answer

Anopheles culicifacies

Answer

Anopheles stephensi

Answer

Anopheles subpictus

Answer

Anopheles fluviatilis

Question 5

Which indicator best measures the operational efficiency of a malaria control programme?

Accepted Answer

Annual blood examination rate

Answer

Infant parasite rate

Answer

Slide positivity rate

Answer

Mosquito bite rate

Question 6

All are features of yellow fever except?

Accepted Answer

Validity of vaccination begins immediately after vaccination

Answer

Caused by vector aedes

Answer

IP 3-6 days

Answer

1 attack gives life long immunity

Question 7

The international quarantine period for yellow fever as approved by the Government of India is ?

Accepted Answer

6 days

Answer

9 days

Answer

10 days

Answer

12 days

Question 8

Based on the type of life cycle, zoonoses are classified into all of the following except -

Accepted Answer

Anthropozoonoses

Answer

Cyclo-zoonoses

Answer

Sporozoonoses

Answer

Meta-zoonoses

Question 9

All of the following are anthropozoonosis except

Accepted Answer

Schistosomiasis

Answer

Rabies

Answer

Plague

Answer

Anthrax

Question 10

To achieve neonatal tetanus elimination, the incidence of neonatal tetanus per 1000 live births should be reduced to less than:

Accepted Answer

1.0

Answer

0.1

Answer

0.5

Answer

0.2

NEET-PG 2013 — Community Medicine