NEET-PG 2012 - Community Medicine Practice Questions

Q: Which cancer type has the most effective screening procedure?

Cervical Cancer. ***Cervical Cancer*** - **Pap smear and HPV testing** represent the most effective cancer screening program, with proven reduction of **>70% in cervical cancer incidence and mortality**. - Screening detects **pre-cancerous lesions (CIN)** during the long latent period, allowing for effective intervention before cancer develops. - Well-established guidelines with high sensitivity, specificity, and cost-effectiveness make it a **public health success story**. - Particularly relevant in Indian context where cervical cancer burden is high and screening programs are being expanded. *Colon Cancer* - **Colonoscopy** and **fecal occult blood testing (FOBT)** are highly effective, allowing direct visualization and removal of precancerous polyps. - While very effective with proven mortality reduction, screening uptake is lower and the procedure is more invasive than cervical cancer screening. - Effectiveness is comparable but cervical cancer screening has achieved greater population-level impact historically. *Prostate Cancer* - Screening with **PSA (prostate-specific antigen) testing** and **digital rectal exam (DRE)** is controversial due to potential for **overdiagnosis and overtreatment** of indolent cancers. - Impact on overall mortality reduction is debated, and it doesn't prevent cancer through detection of precancerous lesions like cervical/colon cancer screening. *Gastric Cancer* - **Gastric cancer screening** is not routinely recommended in most countries including India due to lower prevalence and lack of a highly effective, non-invasive screening method. - **Endoscopy** can detect gastric cancer but is typically performed in symptomatic individuals or high-risk populations (e.g., Japan, Korea), not as a general population screening tool.

Q: Which vaccine is used to prevent cholera?

WC-rBS. ***WC-rBS*** * **WC-rBS** stands for **whole-cell, recombinant B subunit** vaccine, also known as **Dukoral**. * It is an **oral inactivated vaccine** containing killed *Vibrio cholerae* O1 bacteria and the recombinant B subunit of the cholera toxin, providing immunity against cholera. * **WC-rBS is the WHO-prequalified cholera vaccine** widely used in India and recommended for travellers and in epidemic settings. * It provides protection against both O1 and O139 serogroups and offers some cross-protection against ETEC (enterotoxigenic *E. coli*). *CVD 103-HgR* * **CVD 103-HgR** (commercially known as **Vaxchora**) is an **oral live-attenuated cholera vaccine** approved by the FDA. * It is a genetically modified *Vibrio cholerae* O1 Inaba strain with deleted cholera toxin genes. * While this is also a cholera vaccine, **it is primarily used in the United States** and is not the standard vaccine used in India or recommended by WHO for mass vaccination campaigns. * In the Indian context and for NEET-PG examinations, **WC-rBS (Dukoral) is the recognized cholera vaccine**. *Ty21a* * **Ty21a** is an **oral live-attenuated vaccine** used to prevent **typhoid fever**. * It is specifically designed to target *Salmonella Typhi* bacteria, not *Vibrio cholerae*. *None of the options* * This option is incorrect because WC-rBS is the well-established and WHO-recommended vaccine for the prevention of cholera in the Indian context.

Q: What is the concentration of type 3 virus in the trivalent oral polio vaccine?

600,000 TCID 50. ***600,000 TCID 50*** - The **trivalent oral polio vaccine (tOPV)** traditionally contained specific concentrations of each serotype: **type 1 (1,000,000 TCID50/dose)**, **type 2 (100,000 TCID50/dose)**, and **type 3 (600,000 TCID50/dose)**. - Type 3 poliovirus requires a **higher concentration (600,000 TCID50)** compared to type 2 to achieve adequate immunogenicity and protection. - The **World Health Organization (WHO)** established these specific formulations for tOPV to ensure optimal efficacy and safety for each serotype. *100,000 TCID 50* - This is the concentration of **type 2 poliovirus** in tOPV, not type 3. - Due to the **global eradication of wild poliovirus type 2** by 2015, tOPV was replaced with bivalent OPV (bOPV) containing only types 1 and 3 in routine immunization programs. *400,000 TCID 50* - This concentration does not correspond to any standard poliovirus serotype in the traditional trivalent oral polio vaccine. - This value falls between type 2 (100,000) and type 3 (600,000) concentrations but is not used. *300,000 TCID 50* - This concentration is not the standard for any poliovirus serotype in the traditional trivalent oral polio vaccine. - Each serotype has a **distinct, empirically determined concentration** to achieve optimal immunity while minimizing adverse effects.

Q: The primary reservoir for leptospirosis transmission is:

Rat. ***Correct Answer: Rat*** - **Rats** (and other rodents) are considered the primary natural reservoir for *Leptospira* bacteria worldwide and are **asymptomatic carriers**. - They excrete the bacteria in their urine, contaminating water and soil, which serves as the main source of human infection. *Incorrect: Cat* - While cats can become infected with *Leptospira*, they are **not typically considered significant reservoirs** for human transmission. - Their role in the epidemiologic cycle of leptospirosis is generally minor compared to rodents and some other mammals. *Incorrect: Dog* - **Dogs** can contract leptospirosis and excrete the bacteria in their urine, posing a risk to humans, but they are generally considered **incidental hosts or secondary reservoirs**, not the primary one. - Vaccination in dogs helps reduce their role in transmission. *Incorrect: Fish* - **Fish are not known to be reservoirs** for *Leptospira* bacteria. - Leptospirosis is primarily transmitted through contact with infected animal urine, not aquatic life like fish.

Q: Vector of scrub typhus in man?

Leptotrombidium deliense. ***Leptotrombidium deliense*** - This is the **chigger mite** species primarily responsible for transmitting **scrub typhus** to humans. - **Larval mites (chiggers)** of this species feed on human skin and transmit the bacterium *Orientia tsutsugamushi*. *O. tsutsugamushi* - This is the **causative agent** of scrub typhus, not the vector. - It is a **rickettsial bacterium** transmitted by infected chiggers. *Lice* - **Lice** (e.g., *Pediculus humanus corporis*) are vectors for diseases like **epidemic typhus** (caused by *Rickettsia prowazekii*) and **relapsing fever**, but not scrub typhus. - They are **blood-sucking insects** distinct from mites. *Pediculus humanus* - This refers to **human lice**, specifically *Pediculus humanus capitis* (head louse) or *Pediculus humanus corporis* (body louse). - As mentioned, lice transmit diseases like epidemic typhus, not **scrub typhus**.

Q: Which of the following diseases has the maximum Disability-Adjusted Life Years (DALY) loss?

Unipolar depression (Major Depressive Disorder). ***Unipolar depression (Major Depressive Disorder)*** - **Major Depressive Disorder (MDD)** is considered a leading cause of **disability worldwide**, contributing significantly to DALYs due to its high prevalence, chronicity, and disabling nature. - The long-term impact on daily functioning, productivity, and overall quality of life makes it the mental disorder with the largest burden of disease. *Schizophrenia (Mental Disorder)* - While **schizophrenia** causes severe disability and is highly impactful on individuals and society, its prevalence is lower than that of unipolar depression. - The DALY burden for schizophrenia is substantial, but **unipolar depression** affects a much larger proportion of the global population. *Bipolar depression (Bipolar Disorder)* - **Bipolar disorder (depressive episodes)** also contributes significantly to disability, but it is less prevalent than unipolar depression. - Although the depressive phases are often more severe than unipolar depression, the overall DALYs are lower due to its **comparatively lower incidence**. *Mania (Bipolar Disorder Episode)* - **Mania**, a component of bipolar disorder, can cause significant impairment during an episode but is typically **episodic** and less frequent than depressive states in bipolar disorder. - The DALYs attributed to manic episodes alone are generally lower than the overall burden of persistent depressive states found in unipolar depression.

Q: India started 2-dose vaccination strategy for measles, in -

2010. ***2010*** - India implemented the **two-dose measles vaccination strategy** as part of its Universal Immunization Program starting in **2010**. - This decision was based on recommendations to improve immunity and reduce measles incidence, moving from a single-dose to a more effective **two-dose schedule**. *2008* - While important immunization initiatives were ongoing, the specific policy of a **two-dose measles vaccination strategy** had not yet been introduced in India during 2008. - At this time, the focus was primarily on ensuring high coverage of the **first dose** of measles vaccine. *2009* - The year 2009 saw continued efforts to strengthen the Universal Immunization Program, but the official launch of the **two-dose measles vaccination strategy** in India occurred later. - Discussions and planning for the transition were likely underway, but implementation began in the subsequent year. *2011* - By 2011, the **two-dose measles vaccination strategy** was already being implemented across India, having been introduced in 2010. - This year marked a period of expanding coverage and consolidation of the new 2-dose schedule rather than its initial introduction.

Q: What is the primary causative vector of Vagabond disease?

Louse. ***Louse*** - Vagabond disease is a term historically used to describe the chronic skin changes (such as **pigmentation**, **lichenification**, and **excoriations**) resulting from persistent **pediculosis corporis** (body lice infestation). - The **body louse** (*Pediculus humanus corporis*) is the causative agent responsible for these chronic dermatological changes through prolonged infestation. - Body lice are also vectors that can transmit other diseases like **epidemic typhus**, **louse-borne relapsing fever**, and **trench fever**, but vagabond disease itself is the direct result of chronic louse infestation rather than a transmitted pathogen. *Mite* - Mites are responsible for various conditions, such as **scabies** (caused by *Sarcoptes scabiei*) and serve as vectors for **scrub typhus** (transmitted by chiggers, the larval form of trombiculid mites). - However, they are not associated with vagabond disease or the chronic dermatological changes caused by body lice. *Tick* - Ticks are known vectors for a wide range of diseases, including **Lyme disease**, **Rocky Mountain spotted fever**, **anaplasmosis**, and **babesiosis**. - These diseases are transmitted through the bite of infected ticks, which are distinct from the louse-related conditions associated with vagabond disease. *Black Fly* - Black flies (*Simulium* species) are vectors for **onchocerciasis** (river blindness), caused by the parasitic nematode *Onchocerca volvulus*. - While they can cause itchy bites and transmit significant disease, they are not involved in the chronic skin condition known as vagabond disease.

Q: Which of the following studies has given coronary risk factors?

Framingham. ***Framingham*** - The **Framingham Heart Study** is a landmark prospective cohort study that has identified many of the well-known **risk factors for cardiovascular disease**, including hypertension, high cholesterol, smoking, and diabetes. - This ongoing study, started in 1948, has been instrumental in shaping our understanding of **coronary artery disease** development and prevention strategies. *North Karelia* - The **North Karelia Project** was a comprehensive community-based prevention program in Finland that successfully reduced cardiovascular disease risk factors. - While influential in demonstrating how to **implement prevention strategies**, it applied already-known risk factors rather than discovering new ones. - The program focused on reducing smoking, cholesterol, and blood pressure in the population. *Stanford study* - While Stanford University has conducted numerous influential medical studies, there isn't a single "Stanford study" primarily recognized for giving us the comprehensive list of coronary risk factors. - Many institutions contribute to medical knowledge, but the **Framingham Heart Study** stands out for this specific contribution. *MONICA* - The **MONICA (Monitoring Trends and Determinants in Cardiovascular Disease)** Project was a multinational WHO project that aimed to monitor cardiovascular disease trends and determinants. - While it provided valuable data on the **epidemiology of cardiovascular disease** and its risk factors, it primarily assessed trends in established risk factors rather than initially identifying them.

Question 1

Which cancer type has the most effective screening procedure?

Accepted Answer

Cervical Cancer

Answer

Prostate Cancer

Answer

Colon Cancer

Answer

Gastric Cancer

Question 2

Which vaccine is used to prevent cholera?

Accepted Answer

WC-rBS

Answer

CVD 103-HgR

Answer

Ty21 A

Answer

None of the options

Question 3

What is the concentration of type 3 virus in the trivalent oral polio vaccine?

Accepted Answer

600,000 TCID 50

Answer

400,000 TCID 50

Answer

100,000 TCID 50

Answer

300,000 TCID 50

Question 4

The primary reservoir for leptospirosis transmission is:

Accepted Answer

Rat

Answer

Cat

Answer

Dog

Answer

Fish

Question 5

Vector of scrub typhus in man?

Accepted Answer

Leptotrombidium deliense

Answer

O. tsutsugamushi

Answer

Lice

Answer

Pediculus humanus

Question 6

Which of the following diseases has the maximum Disability-Adjusted Life Years (DALY) loss?

Accepted Answer

Unipolar depression (Major Depressive Disorder)

Answer

Schizophrenia (Mental Disorder)

Answer

Bipolar depression (Bipolar Disorder)

Answer

Mania (Bipolar Disorder Episode)

Question 7

All following are at-risk group adults meriting Hepatitis B vaccination in low endemic areas except for which of the following?

Accepted Answer

Diabetics on insulin

Answer

Medical/nursing personnel

Answer

Patients with chronic liver disease

Answer

Patients on chronic hemodialysis

Question 8

India started 2-dose vaccination strategy for measles, in -

Accepted Answer

2010

Answer

2008

Answer

2009

Answer

2011

Question 9

What is the primary causative vector of Vagabond disease?

Accepted Answer

Louse

Answer

Mite

Answer

Tick

Answer

Black Fly

Question 10

Which of the following studies has given coronary risk factors?

Accepted Answer

Framingham

Answer

Stanford study

Answer

MONICA

Answer

North Karelia

NEET-PG 2012 — Community Medicine