NEET-PG 2013 Practice Questions

Q: In the context of demographic studies, how is 'population explosion' defined in terms of growth rate?

> 2%. ***> 2%*** - A **population explosion** is generally defined as a rapid and significant increase in population size, typically characterized by an annual growth rate exceeding **2%**. - This rate indicates a **doubling time** of approximately 35 years or less, leading to substantial demographic changes. - In the context of Indian demographics, this definition is particularly relevant to the period of rapid population growth experienced in the mid-20th century. *0.5% - 1.0%* - A growth rate in this range is considered **moderate** or even **low** for many developing countries and would not be indicative of a "population explosion." - This rate represents a relatively **stable** or slowly increasing population, not the rapid surge implied by the term. *1.5% - 2.0%* - While a 1.5% to 2.0% growth rate is significant, it often falls short of the threshold typically associated with a "population explosion," which implies a more **accelerated** and **unsustainable** rate of increase. - Many countries with this growth rate face challenges, but it's generally not classified as an "explosion" unless other contextual factors are extreme. *1.0% - 1.5%* - A growth rate between 1.0% and 1.5% is considered a **moderate** rate of population increase. - This range does not signify the rapid and often unmanageable growth implied by the term **population explosion**.

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: 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: Infant mortality rate in India is per 1000 live births?

34. ***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.

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: Transovarian transmission is seen in-

Rickettsial diseases. ***Rickettsial diseases*** - **Transovarian transmission** is a key mechanism for the maintenance and spread of **rickettsiae** in arthropod vectors. The bacteria can pass from an infected female arthropod (like a tick or mite) to her offspring via the eggs. - This ensures that the next generation of vectors is already infected and can transmit the disease, even without needing to acquire the pathogen from an infected vertebrate host. *Malaria* - Malaria is transmitted via the bite of an infected **Anopheles mosquito**, which acquires parasites from an infected human. - **Transovarian transmission** does not occur in malaria; mosquitoes are not born with the ability to transmit the parasite. *Filaria* - Filariasis is spread by various **mosquito vectors** (e.g., *Culex*, *Anopheles*, *Aedes*) or **black flies**, which acquire microfilariae from an infected host during a blood meal. - The parasite undergoes development within the insect, but **transovarian transmission** to the insect's offspring does not occur. *None of the options* - This option is incorrect because **rickettsial diseases** do exhibit transovarian transmission, making it a valid answer. - The phenomenon of passing pathogens directly from a female parent to her offspring via the egg is a specific mechanism seen in certain vector-borne diseases.

Q: In a developing country, the prevalence of diabetes mellitus is increasing at an annual rate of 1.8%. Using epidemiological principles similar to the Rule of 70, approximately how many years will it take for the diabetes prevalence to double, and what are the primary healthcare planning implications of this growth rate?

35-46 years. ***35-46 years*** - Using the **Rule of 70**, divide 70 by the annual growth rate (1.8%): 70 / 1.8 ≈ **38.89 years**. This value falls within the 35-46 year range. - The doubling of diabetes prevalence within this timeframe necessitates significant **healthcare planning implications**, including increased demand for diagnostic services, medications, and specialized care, as well as focused preventative measures. *30-35 years* - This range is too low, as the calculated doubling time of approximately **38.89 years** is longer than this range. While close, this timeframe underestimates the actual time needed for prevalence to double. *25-30 years* - This range is significantly lower than the calculated doubling time of approximately **38.89 years**, meaning it underestimates the time required for diabetes prevalence to double by about 9-14 years. *20-25 years* - This range is far too low, as the calculated doubling time of approximately **38.89 years** is much longer. This timeframe would suggest a much higher annual growth rate than the stated 1.8%.

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: 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.

Question 1

In the context of demographic studies, how is 'population explosion' defined in terms of growth rate?

Accepted Answer

> 2%

Answer

0.5% - 1.0%

Answer

1.5% - 2.0%

Answer

1.0% - 1.5%

Question 2

All of the following are anthropozoonosis except

Accepted Answer

Schistosomiasis

Answer

Rabies

Answer

Plague

Answer

Anthrax

Question 3

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 4

Infant mortality rate in India is per 1000 live births?

Accepted Answer

34

Answer

25

Answer

55

Answer

60

Question 5

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 6

Transovarian transmission is seen in-

Accepted Answer

Rickettsial diseases

Answer

Malaria

Answer

Filaria

Answer

None of the options

Question 7

Which of the following statements best describes the operational definition of onchocerciasis elimination?

Accepted Answer

Transmission of O. volvulus has been reduced to a level where it cannot sustain itself in the population.

Answer

All interventions have been successfully implemented.

Answer

There is no recrudescence of the disease after a defined period.

Answer

All of the options are true.

Question 8

In a developing country, the prevalence of diabetes mellitus is increasing at an annual rate of 1.8%. Using epidemiological principles similar to the Rule of 70, approximately how many years will it take for the diabetes prevalence to double, and what are the primary healthcare planning implications of this growth rate?

Accepted Answer

35-46 years

Answer

30-35 years

Answer

25-30 years

Answer

20-25 years

Question 9

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 10

Malaria is transmitted in Rural areas by?

Accepted Answer

Anopheles culicifacies

Answer

Anopheles stephensi

Answer

Anopheles dirus

Answer

None of the options

NEET-PG 2013

Community Medicine