Community Medicine
6 questionsWhat does a highly sensitive test imply about its false negative rate?
What is the Chandler's Index for Hookworm that indicates a significant health problem?
What is the key characteristic of Body Mass Index (BMI) considerations for the Asian population?
What is the role of iodized salt in the iodine deficiency control programme?
Which of the following is not classified as a special incidence rate?
Which of the following is not typically screened for in blood donations?
NEET-PG 2012 - Community Medicine NEET-PG Practice Questions and MCQs
Question 731: What does a highly sensitive test imply about its false negative rate?
- A. High false positive rate
- B. Low false negative rate (Correct Answer)
- C. High true negative rate
- D. High true positive rate
Explanation: ***Low false negative rate*** - A highly **sensitive test** is good at identifying true positives, meaning it correctly identifies most people who have the disease. - Sensitivity = TP/(TP+FN), so high sensitivity mathematically means few false negatives. - This characteristic directly translates to a **low false negative rate**, as few people with the disease will be missed. *High false positive rate* - A high **false positive rate** relates to **specificity**, not sensitivity. - False positive rate = FP/(FP+TN), which measures how many healthy people are incorrectly identified as diseased. - While some sensitive tests may have lower specificity (higher FP rate), this is not a direct implication of high sensitivity. *High true negative rate* - A high **true negative rate** is a characteristic of a highly **specific** test, which correctly identifies people who do **not** have the disease. - True negative rate = TN/(TN+FP) = Specificity. - **Sensitivity** and **specificity** are independent measures, so high sensitivity does not imply a high true negative rate. *High true positive rate* - High **true positive rate** is actually another term for high sensitivity (Sensitivity = TPR = TP/(TP+FN)). - While this is true of a sensitive test, the question specifically asks about the implication for the **false negative rate**. - The **most direct answer** regarding false negatives is "low false negative rate" rather than describing the true positive rate.
Question 732: What is the Chandler's Index for Hookworm that indicates a significant health problem?
- A. > 200
- B. > 100
- C. > 300
- D. > 50 (Correct Answer)
Explanation: ***> 50*** - A Chandler's Index of **> 50** indicates a significant public health problem due to **hookworm infection**. - **Chandler's Index** is calculated as the **average egg count per person in a community** (total hookworm eggs counted ÷ number of persons examined), used to assess the population-level burden of hookworm infection. - A value **> 50** suggests that the community has a significant hookworm problem requiring public health intervention. *> 300* - This value is significantly higher than the threshold for a significant public health problem and would indicate an **extremely severe burden of infection**. - While this represents a very high Chandler's Index, it's not the standard cut-off for defining a "significant" health problem (which is the lower threshold of >50). *> 200* - A Chandler's Index of **> 200** would denote a very high intensity of hookworm infection in the community. - However, this is not the standard threshold used to define when hookworm becomes a "significant" public health issue - the threshold is lower at >50. *> 100* - A Chandler's Index of **> 100** represents a substantial level of hookworm infection within a population. - However, the widely recognized cutoff for a "significant health problem" is **> 50**, indicating public health concern even at this moderate level of community infection burden.
Question 733: What is the key characteristic of Body Mass Index (BMI) considerations for the Asian population?
- A. Increased morbidity at lower values (Correct Answer)
- B. BMI cut-offs for obesity differ from international standards
- C. Increased morbidity at higher BMI values
- D. Obesity is defined as > 25 kg/m2
Explanation: ***Increased morbidity at lower values*** - Due to differences in body composition and fat distribution, Asian populations tend to experience **higher risks of developing obesity-related diseases** (e.g., type 2 diabetes, cardiovascular disease) at **lower BMI values** compared to non-Asian populations. - This increased morbidity at lower BMI values highlights the need for population-specific BMI cut-offs for health risk assessment. *BMI cut-offs for obesity differ from international standards* - While it is true that **BMI cut-offs for obesity differ for Asian populations**, this option does not fully describe *why* these cut-offs differ. - The difference in cut-offs is precisely *because* increased morbidity is seen at lower BMI values, making this option less specific than the correct answer. *Increased morbidity at higher BMI values* - While morbidity does increase at higher BMI values in all populations, this statement is **true for Caucasians and other populations**, but the defining characteristic for Asian populations is the *lower* BMI at which morbidity risk begins to significantly increase. - This option does not capture the unique aspect of BMI and health risks in the Asian population. *Obesity is defined as > 25 kg/m2* - For many Asian populations, a BMI of **> 25 kg/m²** is often used as the cut-off for **overweight**, not necessarily obesity, and **obesity is often defined at > 27.5 kg/m² or 30 kg/m² depending on the specific group**. - The international standard for obesity (BMI ≥ 30 kg/m²) is often considered too high for many Asian populations to capture risk effectively.
Question 734: What is the role of iodized salt in the iodine deficiency control programme?
- A. Primary prevention of iodine deficiency (Correct Answer)
- B. Secondary prevention of iodine deficiency
- C. Tertiary prevention of iodine deficiency
- D. Not applicable
Explanation: ***Primary prevention of iodine deficiency*** - **Iodized salt** is a population-wide strategy to ensure adequate **iodine intake** in communities, preventing deficiency before it even occurs. - It aims to maintain normal **thyroid hormone** production and prevent disorders like **goiter** and **cretinism** in healthy individuals. *Secondary prevention of iodine deficiency* - **Secondary prevention** focuses on early diagnosis and prompt treatment in individuals already showing signs of a disease to prevent progression. - While screening for **iodine deficiency disorders (IDD)** might be secondary prevention, the universal use of iodized salt is not targeted at already deficient individuals but at the entire population. *Tertiary prevention of iodine deficiency* - **Tertiary prevention** involves managing existing conditions to prevent complications, reduce disability, and improve quality of life after a disease has manifested. - This would involve treating conditions like **severe hypothyroidism** or **cretinism** that result from prolonged iodine deficiency, for which **iodized salt** is not a direct treatment but a preventative measure. *Not applicable* - This option is incorrect as **iodized salt** plays a crucial and well-established role in public health for controlling **iodine deficiency**. - The scientific evidence and public health initiatives globally highlight its significant applicability in preventing **iodine deficiency disorders**.
Question 735: Which of the following is not classified as a special incidence rate?
- A. Attack rate
- B. Secondary attack rate
- C. Hospital admission rate
- D. Standardized mortality rate (Correct Answer)
Explanation: ***Standardized mortality rate*** - This is a measure used to compare **mortality rates** between different populations, adjusting for age or other confounding factors. - It is a **standardized mortality measure**, not an incidence rate, and therefore not classified as a special incidence rate. - Special incidence rates measure the occurrence of **new cases** in specific circumstances, whereas SMR is a **comparative mortality metric**. *Attack rate* - The **attack rate** is a classic **special incidence rate** used to describe the proportion of people in a population who became ill during an **epidemic or outbreak**. - It is specifically calculated during a **short, well-defined period**, often relevant to foodborne illnesses or infectious disease outbreaks. *Secondary attack rate* - The **secondary attack rate** is a **special incidence rate** that measures the proportion of susceptible people who develop a disease after being exposed to a **primary case** within a defined population (e.g., household contacts). - It quantifies the **spread of an infectious agent** within a closed population after its introduction. *Hospital admission rate* - This is a **health service utilization indicator** that measures hospital admissions in a population during a specified period. - It is **not classified as a special incidence rate** in standard epidemiological teaching, as it reflects healthcare utilization rather than disease occurrence in outbreak situations.
Question 736: Which of the following is not typically screened for in blood donations?
- A. HIV
- B. HBV
- C. HCV
- D. Epstein-Barr Virus (EBV) (Correct Answer)
Explanation: ***Epstein-Barr Virus (EBV)*** ✓ - EBV is **NOT routinely screened** for in blood donations in India and most countries - While EBV is a common virus (>90% adults are seropositive), it is **not considered a major transfusion-transmitted infection** - The virus is primarily transmitted through saliva; transfusion-associated EBV transmission is **extremely rare and usually not clinically significant** in immunocompetent recipients - Risk-benefit analysis does not support routine screening due to **high prevalence, low clinical impact, and cost considerations** - EBV screening may only be considered for specific recipients (e.g., severely immunocompromised patients) *HIV* - **Routinely screened** in all blood donations worldwide - Screening includes HIV-1 and HIV-2 antibodies and/or HIV antigen/RNA testing - Transfusion-transmitted HIV causes AIDS with severe consequences - Mandatory screening under the Drugs and Cosmetics Act in India *HBV* - **Routinely screened** in all blood donations - Screening includes HBsAg (Hepatitis B surface antigen) testing, and often anti-HBc or HBV DNA - Can cause acute and chronic hepatitis, cirrhosis, and hepatocellular carcinoma - Mandatory screening in India and globally *HCV* - **Routinely screened** in all blood donations - Screening includes anti-HCV antibodies and/or HCV RNA (nucleic acid testing) - Major cause of chronic hepatitis, cirrhosis, and liver cancer - Mandatory screening under blood safety regulations
Internal Medicine
1 questionsAmong the following, most reliable test for screening of diabetes mellitus?
NEET-PG 2012 - Internal Medicine NEET-PG Practice Questions and MCQs
Question 731: Among the following, most reliable test for screening of diabetes mellitus?
- A. Urine sugar
- B. Random sugar
- C. Fasting sugar (Correct Answer)
- D. Glucose tolerance test
Explanation: ***Fasting sugar*** - A **fasting plasma glucose** (FPG) test is the most common and reliable initial test for screening for **diabetes mellitus** because it measures blood glucose after an overnight fast (typically 8-12 hours), providing a baseline level unaffected by recent food intake [1]. - A fasting glucose level of **≥ 126 mg/dL** (7.0 mmol/L) on two separate occasions is diagnostic of diabetes, making it an excellent screening tool for identifying individuals with impaired glucose metabolism [1]. *Random sugar* - A random plasma glucose test can be used to diagnose diabetes if the level is **≥ 200 mg/dL** (11.1 mmol/L) in a symptomatic individual, but it is less reliable for screening asymptomatic individuals due to its variability depending on recent food intake [1]. - Because it can be measured at any time of day without regard to the last meal, it has a **lower sensitivity** for detecting early stages of diabetes compared to fasting glucose. *Glucose tolerance test* - An **oral glucose tolerance test** (OGTT) is highly sensitive and specific for diagnosing diabetes and impaired glucose tolerance, but it is more cumbersome and time-consuming, involving multiple blood draws over two hours after consuming a sugary drink. - While it is a definitive diagnostic test, its complexity makes it **less practical for routine screening** in large populations compared to simpler tests like fasting plasma glucose. *Urine sugar* - The presence of glucose in urine (glycosuria) indicates that blood glucose levels have exceeded the **renal threshold** (typically around 180 mg/dL), meaning the kidneys are unable to reabsorb all the glucose. - This is a **less sensitive and specific** method for screening, as it only becomes positive once blood glucose is significantly elevated, and it does not detect milder forms of impaired glucose metabolism or early diabetes.
Microbiology
1 questionsWhat is the correct order of application of reagents in the complete Gram staining procedure?
NEET-PG 2012 - Microbiology NEET-PG Practice Questions and MCQs
Question 731: What is the correct order of application of reagents in the complete Gram staining procedure?
- A. Gentian violet → Iodine → Alcohol/Acetone → Safranin (Correct Answer)
- B. Iodine → Gentian violet → Alcohol/Acetone → Safranin
- C. Safranin → Gentian violet → Iodine → Alcohol/Acetone
- D. Gentian violet → Alcohol/Acetone → Iodine → Safranin
Explanation: **Gentian violet → Iodine → Alcohol/Acetone → Safranin** - **Gentian violet** (or crystal violet) is the **primary stain** that colors all cells purple. - **Iodine** acts as a **mordant**, forming a crystal violet-iodine complex within the cell walls. - **Alcohol/Acetone** is the **decolorizer**, washing out the primary stain from Gram-negative cells but not from Gram-positive cells. - Finally, **Safranin** is the **counterstain** that stains decolorized Gram-negative cells pink or red. *Iodine → Gentian violet → Alcohol/Acetone → Safranin* - **Iodine** is a mordant and needs a primary stain (like gentian violet) to bind to and form a complex; applying it first would not effectively stain the cells. - The correct sequence requires the primary stain to be applied before the mordant can fix it. *Safranin → Gentian violet → Iodine → Alcohol/Acetone* - **Safranin** is a counterstain and should be applied last to stain the decolorized Gram-negative cells, not as the first reagent. - Applying reagents out of order would lead to incorrect staining results, as **safranin** is meant to provide contrast after decolorization. *Gentian violet → Alcohol/Acetone → Iodine → Safranin* - **Alcohol/Acetone** (decolorizer) is applied too early in this sequence; it should be used after the mordant (iodine) has formed a complex with the primary stain. - Applying the decolorizer before the mordant would prevent the formation of the crystal violet-iodine complex, leading to incorrect differentiation between Gram-positive and Gram-negative bacteria.
Obstetrics and Gynecology
1 questionsWhat is the energy requirement in late pregnancy?
NEET-PG 2012 - Obstetrics and Gynecology NEET-PG Practice Questions and MCQs
Question 731: What is the energy requirement in late pregnancy?
- A. 2000 calories
- B. 2500 calories (Correct Answer)
- C. 1400 calories
- D. 3000 calories
Explanation: ***2500 calories*** - The energy requirement for women in late pregnancy (third trimester) is approximately **2300-2500 calories per day**, which includes an additional **300-450 calories** above pre-pregnancy needs. - This increased energy intake supports **fetal growth and development**, increased maternal blood volume, uterine growth, and the metabolic demands of pregnancy. - The **2500 calorie** recommendation represents the upper range suitable for most pregnant women with normal activity levels. *2000 calories* - This amount is closer to the **pre-pregnancy energy requirement** for an average woman, but is **insufficient** for late pregnancy. - During the third trimester, failing to meet increased caloric needs can compromise **fetal growth** and lead to **inadequate gestational weight gain**. *1400 calories* - This amount is **severely insufficient** for the increased metabolic demands of late pregnancy. - An inadequate calorie intake can compromise **fetal growth**, lead to **intrauterine growth restriction (IUGR)**, and cause **maternal nutrient deficiencies**. *3000 calories* - This caloric intake is generally **too high** for the average pregnant woman with normal activity levels. - Excessive intake is only justified in cases of **multiple gestation**, unusually high physical activity, or specific medical conditions. - Consuming 3000 calories per day without proper justification can lead to **excessive gestational weight gain**, gestational diabetes, and macrosomia.
Surgery
1 questionsWhich of the following actions is NOT recommended when dealing with a patient who has been bitten by a snake?
NEET-PG 2012 - Surgery NEET-PG Practice Questions and MCQs
Question 731: Which of the following actions is NOT recommended when dealing with a patient who has been bitten by a snake?
- A. Reassurance
- B. Immobilization of the affected limb
- C. Clean with soap and water
- D. Local incision (Correct Answer)
Explanation: ***Local incision*** - Making an incision at the bite site can **worsen tissue damage**, increase the risk of infection, and does not effectively remove venom. - This practice is **outdated** and potentially harmful, as venom spreads rapidly through the lymphatic system rather than being localized in a way that incision can help. - **Local incision is NOT recommended** and is a contraindicated first-aid measure. *Immobilization of the affected limb* - Immobilizing the bitten limb helps **slow the spread of venom** through the lymphatic system. - This is a **recommended first-aid measure**, especially for neurotoxic snakebites, and should be done by keeping the limb at or below heart level. - Proper immobilization involves splinting the limb without restricting blood flow. *Reassurance* - Overt fear and anxiety can lead to symptoms like **tachycardia** and **hypertension**, which can exacerbate the effects of the venom. - **Calming the patient** helps reduce the physiological stress response, which is crucial as panic can worsen the clinical picture. - Reassurance is a **recommended supportive measure**. *Clean with soap and water* - Cleaning the wound helps remove surface venom and **reduce the risk of secondary bacterial infection**. - This is a **recommended basic first-aid measure** that promotes wound hygiene without interfering with venom management.