Community Medicine
8 questionsWhat is the most important test to assess the prevalence of tuberculosis infection in a community?
In a normal curve, the area between one standard deviation on either side of the mean will include:
Match List-I with List-II and select the correct answer using the code given below the Lists:
Which of the following insecticides is not used as a larvicide?
An outbreak of Viral Hepatitis was reported from a town between June and August of a particular year. 60% of cases occurred in July. Exposure of the community to infection is from:
Which one of the following indicators is not included in Millennium Development Goals?
Severity of a disease is measured by:
‘Spot map’ in epidemiological studies refer to variation in the distribution of a disease at:
UPSC-CMS 2014 - Community Medicine UPSC-CMS Practice Questions and MCQs
Question 91: What is the most important test to assess the prevalence of tuberculosis infection in a community?
- A. Mass miniature radiography
- B. Tuberculin test (Correct Answer)
- C. Sputum examination of AFB
- D. Clinical examination
Explanation: ***Tuberculin test*** - The **tuberculin skin test (TST)**, or Mantoux test, measures the delayed-type hypersensitivity reaction to tuberculin, indicating prior exposure to *Mycobacterium tuberculosis*. - A positive TST reflects **tuberculosis infection**, whether latent or active, making it a valuable tool for assessing prevalence in a community. *Mass miniature radiography* - This method, now largely replaced by digital radiography, primarily detects **active pulmonary tuberculosis** by identifying lung lesions like infiltrates or cavities. - It is less effective for detecting **latent tuberculosis infection (LTBI)**, which represents the majority of infected individuals in a community. *Sputum examination of AFB* - This test is crucial for diagnosing **active pulmonary tuberculosis** by identifying acid-fast bacilli (AFB) in sputum. - However, it only detects individuals who are actively shedding bacteria and may not capture the broader prevalence of **latent infection** in a community. *Clinical examination* - A clinical examination primarily identifies individuals with **symptoms of active tuberculosis**, such as persistent cough, fever, or weight loss. - It is not a reliable method for assessing the overall **prevalence of tuberculosis infection**, particularly asymptomatic latent cases, in a community.
Question 92: In a normal curve, the area between one standard deviation on either side of the mean will include:
- A. 70 – 85% of the values
- B. 95% of the values
- C. Approximately 68% of the values (Correct Answer)
- D. Less than 50% of the values
Explanation: ***Approximately 68% of the values*** - In a **normal distribution** (bell curve), approximately **68% of data points** fall within one standard deviation ($\pm1\sigma$) from the mean. - This is a fundamental property of the **empirical rule** (or 68-95-99.7 rule) in statistics. *70 – 85% of the values* - This range is too broad and does not accurately reflect the specific percentage for **one standard deviation**. - While it overlaps with the correct value, it is not the precise percentage associated with $\pm1\sigma$. *95% of the values* - This percentage refers to the data included within **two standard deviations** ($\pm2\sigma$) from the mean in a normal distribution, not one. - The **empirical rule** states that approximately 95% of data falls within two standard deviations. *Less than 50% of the values* - This is incorrect, as the range of **one standard deviation** on either side of the mean covers more than half of the data. - The mean itself divides the data into two 50% halves, so incorporating any deviation around it will cover more than 50%.
Question 93: Match List-I with List-II and select the correct answer using the code given below the Lists:
- A. A→1 B→2 C→4 D→3
- B. A→3 B→2 C→4 D→1
- C. A→3 B→4 C→2 D→1 (Correct Answer)
- D. A→1 B→4 C→2 D→3
Explanation: ***Correct Answer: A→3, B→4, C→2, D→1*** **Understanding Health Education Methods:** **A. Symposium → 3. Series of speeches** - A symposium is a formal meeting where multiple experts deliver **sequential speeches** on different aspects of a selected subject - Each speaker presents their perspective, typically without much interaction between speakers during the presentation **B. Panel Discussion → 4. Discussion among the speakers** - A panel involves **interactive discussion among panelists** (experts) on a particular topic - Characterized by dialogue and exchange of views between speakers, often followed by audience questions **C. Workshop → 2. Arriving at a plan of action** - A workshop is a **participatory, problem-solving session** designed to achieve practical outcomes - Participants actively engage in exercises and activities to develop concrete action plans or solutions **D. Role-play → 1. Dramatizing a situation** - Role-play involves **acting out scenarios** to experience different perspectives - Participants assume roles and dramatize situations to understand behaviors, emotions, and decision-making processes *Key Differentiation:* - Symposium = One-way presentations (speakers → audience) - Panel = Two-way discussion (speakers ↔ speakers) - Workshop = Participatory action planning - Role-play = Experiential learning through dramatization
Question 94: Which of the following insecticides is not used as a larvicide?
- A. Dichlorvos
- B. Paris green
- C. Abate
- D. Fenthion (Correct Answer)
Explanation: ***Fenthion*** - **Fenthion** is an **organophosphate insecticide** primarily used as an **adulticide** for **mosquitoes** and other flying insects. - While it can target adult mosquitoes, it is **not commonly used or recommended as a larvicide** due to its higher toxicity profile and environmental concerns compared to other dedicated larvicides. *Dichlorvos* - **Dichlorvos** (DDVP) is an organophosphate insecticide that has been used as a **larvicide**, particularly in situations where rapid knockdown of larvae is required. - It is known for its **quick action** and **fumigant properties**, making it effective against early mosquito stages. *Paris green* - **Paris green** (copper(II) acetoarsenite) is historically one of the **earliest larvicides** used to control mosquito larvae. - It acts as a **stomach poison** when ingested by mosquito larvae. *Abate* - **Abate** (temephos) is a widely used **organophosphate larvicide** known for its **low toxicity to mammals** and aquatic organisms at recommended doses. - It is effective against mosquito larvae in various breeding sites, including drinking water, making it a **preferred choice for public health programs**.
Question 95: An outbreak of Viral Hepatitis was reported from a town between June and August of a particular year. 60% of cases occurred in July. Exposure of the community to infection is from:
- A. Multiple sources over prolonged periods
- B. Multiple sources for a short period
- C. A common single source for prolonged periods
- D. A single source for a short period (Correct Answer)
Explanation: ***A single source for a short period*** - This describes a **point source outbreak**, the classic pattern seen in this scenario - **60% of cases in July** indicates exposure occurred over a **brief period** (likely days to weeks before July) - The 3-month span (June-August) represents the **distribution of cases around the incubation period** of viral hepatitis (typically 2-6 weeks for Hepatitis A) - Common examples: **contaminated water supply**, food at a community gathering, or other single exposure event - This is the **textbook presentation** of a point source epidemic with a characteristic sharp peak *Multiple sources for a short period* - This would produce **multiple peaks** or an irregular epidemic curve, not a single peak in July - Multiple sources would not create the concentrated 60% clustering observed - The pattern described is too uniform for multiple independent sources *A common single source for prolonged periods* - This describes a **continuous common source outbreak** with an extended epidemic curve - Cases would be **distributed more evenly** across June-August without a sharp peak - Example: ongoing contamination of a water supply over months - The 60% concentration in July rules out this pattern *Multiple sources over prolonged periods* - This would result in **endemic disease** or a very flat, prolonged epidemic curve - No sharp peak would be observed - The temporal clustering contradicts this pattern
Question 96: Which one of the following indicators is not included in Millennium Development Goals?
- A. Maternal mortality ratio
- B. Suicide rate per 100,000 population
- C. T.B. death rate per 100,000 children (0 – 4 years of age) (Correct Answer)
- D. Under five mortality rate
Explanation: ***T.B. death rate per 100,000 children (0 – 4 years of age)*** - While **tuberculosis** was addressed in **MDG 6** (Combat HIV/AIDS, malaria, and other diseases), this **specific age-stratified indicator** was not directly enumerated in the official MDG indicator framework. - The MDG indicators for TB included: **prevalence of tuberculosis**, **tuberculosis incidence rate**, **proportion of tuberculosis cases detected and cured under DOTS**, and general TB death rates - but NOT age-specific pediatric TB mortality rates for the 0-4 year age group. - This makes it the correct answer as it represents a specific metric formulation that was not part of the official MDG monitoring framework, despite TB being included in the broader goals. *Maternal mortality ratio* - The **maternal mortality ratio** was a **key indicator under MDG 5** (Improve Maternal Health). - Target 5.A specifically aimed to reduce the maternal mortality ratio by three-quarters between 1990 and 2015. - This was one of the core reproductive health indicators monitored globally. *Suicide rate per 100,000 population* - The **suicide rate** was not included in the Millennium Development Goals framework. - Mental health indicators, including suicide rates, were notably absent from the MDGs, which focused on infectious diseases, maternal and child health, poverty, education, and environmental sustainability. - However, among the options listed, the **TB death rate for children 0-4 years** is considered the answer because it represents a more specific technical distinction about indicator formulation within a disease area (TB) that WAS included in the MDGs, whereas suicide was entirely outside the MDG scope. *Under five mortality rate* - The **under-five mortality rate** was a **central indicator under MDG 4** (Reduce Child Mortality). - Target 4.A aimed to reduce the under-five mortality rate by two-thirds between 1990 and 2015. - This was measured as deaths per 1,000 live births before age five.
Question 97: Severity of a disease is measured by:
- A. Incidence rate
- B. Attributable risk
- C. Relative risk
- D. Case fatality rate (Correct Answer)
Explanation: ***Case fatality rate*** - The **case fatality rate (CFR)** directly measures the **severity** of a disease by indicating the proportion of individuals diagnosed with a disease who ultimately die from it. - A higher CFR implies a more lethal or severe disease. *Incidence rate* - The **incidence rate** measures the **frequency of new cases** of a disease in a population over a specified period. - It reflects how quickly a disease is spreading, not its severity. *Attributable risk* - **Attributable risk (AR)** quantifies the proportion of disease incidence in an exposed group that can be attributed to the exposure. - It measures the **public health impact** of an exposure, not the inherent severity of the disease itself. *Relative risk* - **Relative risk (RR)** compares the probability of an event (e.g., disease development) in an **exposed group** to the probability of the event in an **unexposed group**. - It indicates the **strength of association** between an exposure and a disease, not the severity of the disease in affected individuals.
Question 98: ‘Spot map’ in epidemiological studies refer to variation in the distribution of a disease at:
- A. International level
- B. Local level (Correct Answer)
- C. Rural – urban level
- D. National level
Explanation: ***Local level*** - A **spot map** is an epidemiological tool used to visualize the geographical distribution of disease cases within a **small, defined area**, such as a neighborhood or a single city. - It helps in identifying **clusters or hot-spots** of disease occurrence, which can be crucial for locating potential sources of infection or environmental hazards. *International level* - While disease distribution can be mapped internationally, a "spot map" specifically refers to a **finer-grain analysis** at a much smaller geographical scale, not across multiple countries. - Maps at the international level are often used for **global burden of disease** studies or pandemic tracking, which require broader summaries rather than individual case plotting. *Rural – urban level* - Mapping at the rural-urban level indicates differences between these two broad categories, but a spot map provides even more specific detail within those areas. - It shows the precise location of cases, allowing for insights into localized environmental or social factors, rather than just a general rural vs. urban comparison. *National level* - National-level mapping provides an overview of disease prevalence or incidence across an entire country, which is a much larger scale than a spot map. - A spot map is designed to highlight **precise locations** of cases within a more contained geographical area, making it less suitable for broad national-level trends.
Internal Medicine
2 questionsTuberculosis in HIV positive individuals is characterized by which of the following? 1. More frequent negative sputum smears. 2. More false–negative tuberculin test results. 3. More extra–pulmonary tuberculosis. 4. More cavitating lesions in lungs as shown by chest X-ray. Select the correct answer using the code given below:
Consider the following features of cholera: 1. Onset with purging. 2. No nausea or retching. 3. No tenesmus. 4. Leukocytosis. Which of the above features of cholera differentiate it from food poisoning?
UPSC-CMS 2014 - Internal Medicine UPSC-CMS Practice Questions and MCQs
Question 91: Tuberculosis in HIV positive individuals is characterized by which of the following? 1. More frequent negative sputum smears. 2. More false–negative tuberculin test results. 3. More extra–pulmonary tuberculosis. 4. More cavitating lesions in lungs as shown by chest X-ray. Select the correct answer using the code given below:
- A. 1, 2, 3 and 4
- B. 1 and 2 only
- C. 3 and 4 only
- D. 1, 2 and 3 only (Correct Answer)
Explanation: ***1, 2, and 3 only*** - HIV coinfection impairs cell-mediated immunity, leading to **atypical presentations** of TB [1]. All three options (more frequent negative sputum smears, more false-negative tuberculin tests, and more extrapulmonary TB) are characteristic of TB in HIV-positive individuals due to this **immunodeficiency** [2]. - The immunocompromised state often results in a **diminished inflammatory response**, making diagnosis more challenging and dissemination more likely. *1, 2, 3 and 4* - This option incorrectly includes "more cavitating lesions in lungs as shown by chest X-ray" as a characteristic feature. HIV-positive individuals, particularly those with advanced immunodeficiency, tend to have **fewer cavitating lesions** because their immune system is less capable of mounting the robust inflammatory response required for cavitation [1]. - Cavitation is more typical of **immunocompetent** individuals with pulmonary TB [1]. *3 and 4 only* - This option is incorrect because, while **more extrapulmonary tuberculosis** is characteristic, **more cavitating lesions** are generally not observed in HIV-positive individuals; in fact, the opposite is true. - The combination of these two points together makes this option largely inaccurate. *1 and 2 only* - While **more frequent negative sputum smears** and **false-negative tuberculin tests** [2] are indeed characteristic, this option is incomplete as it misses the increased prevalence of **extrapulmonary TB** [3], which is a significant feature in HIV-positive individuals. - HIV-related immunodeficiency often leads to the widespread dissemination of *Mycobacterium tuberculosis* outside the lungs [3].
Question 92: Consider the following features of cholera: 1. Onset with purging. 2. No nausea or retching. 3. No tenesmus. 4. Leukocytosis. Which of the above features of cholera differentiate it from food poisoning?
- A. 2, 3 and 4
- B. 1, 2 and 3 (Correct Answer)
- C. 1, 2 and 4
- D. 1, 2, 3 and 4
Explanation: ***1, 2 and 3*** - **Cholera** classically presents with abrupt onset of **painless, watery diarrhea** (purging), often described as "rice-water" stools, typically without significant nausea, retching, or tenesmus [1], [2]. Food poisoning caused by bacterial toxins often involves **nausea, vomiting**, and sometimes abdominal cramps and tenesmus, making features 1, 2, and 3 distinguishing [1], [2]. - The absence of significant inflammation in cholera, unlike many forms of food poisoning, also means that systemic inflammatory markers and symptoms like **fever** are less prominent, and there is no **leukocytosis**. *2, 3 and 4* - This option incorrectly includes the absence of **leukocytosis** as a differentiating feature when food poisoning can also be non-inflammatory, and it omits the crucial feature of **onset with purging**, which is highly characteristic of cholera [1]. - While lack of nausea/retching and tenesmus are key, including leukocytosis as a differentiator without considering other factors is misleading. *1, 2 and 4* - This option misses the absence of **tenesmus** (3), which is a key differentiating feature where **cholera** typically causes painless, watery stools without the straining associated with inflammatory bowel conditions or some types of food poisoning [1], [2]. - It also includes **leukocytosis** (4), which is typically absent in cholera but can be present or absent in food poisoning depending on the cause, making it less specific for differentiation than other features. *1, 2, 3 and 4* - While features 1, 2, and 3 are indeed differentiating, feature 4, **leukocytosis**, is **incorrect** as a differentiating factor in the context of cholera. Cholera typically does not cause leukocytosis because it is a non-inflammatory enterotoxin-mediated illness. - Many forms of food poisoning, especially those mediated by toxins or non-invasive bacteria, also do not cause significant leukocytosis.