Malaria is transmitted in Rural areas by?
What is the most common Anopheles mosquito responsible for malaria in India?
Which indicator best measures the operational efficiency of a malaria control programme?
All are features of yellow fever except?
The international quarantine period for yellow fever as approved by the Government of India is ?
Based on the type of life cycle, zoonoses are classified into all of the following except -
All of the following are anthropozoonosis except
To achieve neonatal tetanus elimination, the incidence of neonatal tetanus per 1000 live births should be reduced to less than:
Which day is not included in the pre-exposure prophylaxis dose schedule for the rabies vaccine?
In which condition is a night blood survey performed?
NEET-PG 2013 - Community Medicine NEET-PG Practice Questions and MCQs
Question 41: Malaria is transmitted in Rural areas by?
- A. Anopheles stephensi
- B. Anopheles dirus
- C. Anopheles culicifacies (Correct Answer)
- D. None of the options
Explanation: ***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.
Question 42: What is the most common Anopheles mosquito responsible for malaria in India?
- A. Anopheles stephensi
- B. Anopheles subpictus
- C. Anopheles culicifacies (Correct Answer)
- D. Anopheles fluviatilis
Explanation: ***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.
Question 43: Which indicator best measures the operational efficiency of a malaria control programme?
- A. Infant parasite rate
- B. Slide positivity rate
- C. Mosquito bite rate
- D. Annual blood examination rate (Correct Answer)
Explanation: ***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.
Question 44: All are features of yellow fever except?
- A. Caused by vector aedes
- B. IP 3-6 days
- C. 1 attack gives life long immunity
- D. Validity of vaccination begins immediately after vaccination (Correct Answer)
Explanation: ***Validity of vaccination begins immediately after vaccination*** - Yellow fever vaccine is highly effective, but **immunity does not develop immediately**; it typically offers protection starting **10 days after vaccination**. - This delay is crucial for travelers to endemic areas, as they need to be vaccinated well in advance to ensure protection. *IP 3-6 days* - The **incubation period (IP)** for yellow fever is indeed short, usually ranging from **3 to 6 days** after the bite of an infected mosquito. - This brief incubation period contributes to the rapid onset of symptoms once infected. *1 attack gives life long immunity* - Similar to many viral infections, a single bout of yellow fever infection generally provides **lifelong immunity** against future infections. - This is why the vaccine is so effective, as it mimics natural infection to induce comprehensive, long-term protection. *Caused by vector aedes* - Yellow fever is transmitted primarily by **Aedes mosquitoes**, particularly **Aedes aegypti**, which are responsible for urban and jungle cycles of transmission. - These mosquitoes are prevalent in tropical and subtropical regions of Africa and South America.
Question 45: The international quarantine period for yellow fever as approved by the Government of India is ?
- A. 6 days (Correct Answer)
- B. 9 days
- C. 10 days
- D. 12 days
Explanation: ***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.
Question 46: Based on the type of life cycle, zoonoses are classified into all of the following except -
- A. Cyclo-zoonoses
- B. Anthropozoonoses (Correct Answer)
- C. Sporozoonoses
- D. Meta-zoonoses
Explanation: ***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.
Question 47: All of the following are anthropozoonosis except
- A. Rabies
- B. Plague
- C. Anthrax
- D. Schistosomiasis (Correct Answer)
Explanation: ***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.
Question 48: To achieve neonatal tetanus elimination, the incidence of neonatal tetanus per 1000 live births should be reduced to less than:
- A. 0.1
- B. 0.5
- C. 1.0 (Correct Answer)
- D. 0.2
Explanation: ***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 49: Which day is not included in the pre-exposure prophylaxis dose schedule for the rabies vaccine?
- A. Day 0
- B. Day 7
- C. Day 28
- D. Day 3 (Correct Answer)
Explanation: ***Day 3*** - The standard pre-exposure prophylaxis (PrEP) schedule for rabies vaccine typically involves three doses given on **Day 0, Day 7, and Day 21 or 28**. - A dose on Day 3 is **not part of the standard recommended PrEP schedule**. *Day 0* - This is the **initial dose** in the pre-exposure prophylaxis series for rabies. - It marks the beginning of the vaccination schedule to build immunity. *Day 7* - This is the **second dose** in the pre-exposure prophylaxis series for rabies. - It follows the initial dose and is crucial for developing a robust immune response. *Day 28* - This dose, along with Day 21, can be the **final dose** in the pre-exposure prophylaxis series for rabies, depending on the specific regimen used. - It completes the primary vaccination course to ensure long-lasting protection.
Question 50: In which condition is a night blood survey performed?
- A. Lymphatic filariasis (Correct Answer)
- B. Typhoid fever
- C. Malaria infection
- D. Visceral leishmaniasis
Explanation: ***Lymphatic filariasis*** - A **night blood survey** is crucial for diagnosing lymphatic filariasis because the microfilariae of species like *Wuchereria bancrofti* and *Brugia malayi* exhibit **nocturnal periodicity**, meaning they are most abundant in peripheral blood between 10 PM and 2 AM. - Collecting blood at night maximizes the chance of detecting these parasites, which are responsible for the disease. *Typhoid fever* - Diagnosis of **typhoid fever** primarily relies on **blood cultures** taken during the febrile phase, or stool/urine cultures later in the disease. - A night blood survey is not relevant for detecting the causative bacterium, *Salmonella Typhi*. *Malaria infection* - While a **blood smear** is essential for diagnosing malaria, the timing of blood collection is less critical than for filariasis, although peak parasite density can vary. - **Malaria parasites** are typically detected in blood samples taken during symptomatic periods, regardless of specific time of day. *Visceral leishmaniasis* - **Visceral leishmaniasis** is diagnosed by detecting parasites in samples from **bone marrow**, spleen, or lymph nodes, or through serological tests for antibodies. - A night blood survey is not used in the diagnosis of *Leishmania donovani* infection.