Health Impacts of Climate Change — MCQs

10 questions

All of the following are involved in the pathogenesis of heat stroke EXCEPT:

HIV sentinel surveillance is used for:

Calculate the maternal mortality ratio (MMR) for the year 2023, given the following data: - Total live births: 4,000 - Women who died: 6 (1 due to a road traffic accident (RTA), 1 due to sepsis, 1 due to obstructed labor, 1 due to eclampsia, 1 due to ectopic pregnancy, and 1 due to a snake bite)

Chronic lung disease in infancy is defined as

In human beings, the least useful physiological response to low environmental temperature is:

Which of the following is a direct health impact of climate change?

The difference between the incidence in the exposed and non-exposed group is best given by:

Which of the following statements is TRUE regarding Disability-Adjusted Life Year (DALY)?

A drug used in a patient with increased IOP, optic disc changes, and ciliary congestion that acts by increasing uveoscleral outflow to decrease IOP is:

Q10

In a patient who has been in a state of starvation for 72 hours, which of the following is the primary mechanism for maintaining blood glucose levels?

Health Impacts of Climate Change Indian Medical PG Practice Questions and MCQs

Question 1: All of the following are involved in the pathogenesis of heat stroke EXCEPT:

A. Failure of thermoregulation
B. Dehydration
C. Increased metabolic heat production
D. Excessive sweating (Correct Answer)

Explanation: ***Excessive sweating*** - In **established heatstroke**, there is typically **absence of sweating (anhidrosis)** rather than excessive sweating, particularly in classic non-exertional heatstroke. - While profuse sweating may occur initially during heat stress and in exertional heatstroke, the defining feature of established heatstroke is the **failure of sweating mechanisms**, resulting in hot, dry skin. - The cessation of sweating is a **consequence** of overwhelmed thermoregulatory mechanisms rather than a pathogenic factor, making excessive sweating the exception among the given options. *Dehydration* - **Dehydration** is a major contributing factor to heatstroke pathogenesis as it reduces plasma volume and impairs heat dissipation through sweating and cutaneous vasodilation. - Volume depletion compromises cardiovascular compensatory mechanisms needed for heat loss. *Failure of thermoregulation* - The hallmark of heatstroke pathogenesis is **failure of central thermoregulatory mechanisms** in the hypothalamus, leading to uncontrolled rise in core body temperature above 40°C (104°F). - This represents the central breakdown that defines heatstroke as a clinical entity. *Increased metabolic heat production* - **Increased metabolic heat production** is a key pathogenic factor, especially in exertional heatstroke during intense physical activity. - Endogenous heat production from muscle activity, combined with environmental heat load and impaired heat dissipation, overwhelms thermoregulatory capacity.

Question 2: HIV sentinel surveillance is used for:

A. Detection of high-risk group
B. Prevalence of HIV infection
C. Monitoring trends in HIV infection (Correct Answer)
D. Monitoring disease trends

Explanation: ***Monitoring trends in HIV infection*** - **HIV sentinel surveillance** is specifically designed to track **HIV prevalence trends** over time in selected sentinel populations (ANC attendees, STD clinic attendees, high-risk groups). - The primary objective is to monitor **how HIV infection rates change** over time, helping identify emerging epidemics, evaluate intervention programs, and guide public health policy. - As per **NACO and WHO guidelines**, sentinel surveillance provides repeated cross-sectional prevalence measurements at fixed sites to detect temporal trends in HIV infection. *Monitoring disease trends* - This is **too broad and vague** for the specific purpose of HIV sentinel surveillance. - "Disease trends" could refer to AIDS progression, opportunistic infections, or other disease manifestations, which are **not the focus** of sentinel surveillance. - Sentinel surveillance specifically tracks **infection (seroprevalence)**, not general disease patterns. *Prevalence of HIV infection* - While sentinel surveillance **does measure prevalence**, this is a **method rather than the ultimate purpose**. - Prevalence measurements are taken repeatedly at different time points specifically to **monitor trends**, making this incomplete as the primary objective. *Detection of high-risk group* - Identification of high-risk groups is typically done through **epidemiological studies** and behavioral surveys, not sentinel surveillance. - Sentinel surveillance may **include** high-risk populations as sentinel sites, but its purpose is to monitor trends **within** these groups, not to detect them.

Question 3: Calculate the maternal mortality ratio (MMR) for the year 2023, given the following data: - Total live births: 4,000 - Women who died: 6 (1 due to a road traffic accident (RTA), 1 due to sepsis, 1 due to obstructed labor, 1 due to eclampsia, 1 due to ectopic pregnancy, and 1 due to a snake bite)

A. 75 per 100,000 live births
B. 150 per 100,000 live births
C. 100 per 100,000 live births (Correct Answer)
D. 125 per 100,000 live births

Explanation: ***Correct: 100 per 100,000 live births*** - The **maternal mortality ratio (MMR)** includes deaths directly or indirectly due to pregnancy, childbirth, or within 42 days of termination of pregnancy, **excluding accidental or incidental causes**. - In this scenario, **4 maternal deaths** are identified: sepsis (direct), obstructed labor (direct), eclampsia (direct), and ectopic pregnancy (direct). - **Excluded deaths**: RTA and snake bite are **incidental/accidental deaths** not related to pregnancy complications. - **Calculation**: MMR = (4 / 4,000) × 100,000 = **100 per 100,000 live births** *Incorrect: 75 per 100,000 live births* - This would incorrectly count only **3 maternal deaths** instead of 4, suggesting underestimation or exclusion of a valid maternal death (e.g., ectopic pregnancy). - Represents a **miscalculation** that underestimates maternal mortality burden. *Incorrect: 150 per 100,000 live births* - This would incorrectly include **6 deaths** (all deaths including RTA and snake bite), failing to exclude incidental causes. - Including **non-maternal accidental deaths** inflates MMR and misrepresents actual maternal health outcomes. *Incorrect: 125 per 100,000 live births* - This would incorrectly count **5 deaths**, suggesting inclusion of one incidental death (either RTA or snake bite). - Fails to properly identify and exclude **both incidental deaths**, leading to an overestimated ratio.

Question 4: Chronic lung disease in infancy is defined as

A. Need for supplemental oxygen at 36 weeks postmenstrual age (Correct Answer)
B. Tachypnoea > 50 breaths/ min within 1 week of birth
C. Presence of bilateral infiltrates on chest Xray for 2 weeks
D. Reticulogranular pattern on chest Xray for 6 weeks

Explanation: ***Need for supplemental oxygen at 36 weeks after conception*** - **Chronic lung disease (CLD)**, also known as **bronchopulmonary dysplasia (BPD)**, is defined by the need for **supplemental oxygen** at 36 weeks postmenstrual age (corrected gestational age) or at 56 days postnatal age, whichever comes first, for infants born before 32 weeks gestation. - This definition reflects persistent respiratory morbidity requiring ongoing support, indicative of lung injury and abnormal development. *Tachypnoea > 50 breaths/ min within 1 week of birth* - **Tachypnoea** within the first week of birth can be a symptom of various neonatal respiratory conditions, such as **transient tachypnoea of the newborn (TTN)** or **respiratory distress syndrome (RDS)**, but it is not a defining feature of CLD. - CLD is characterized by a *prolonged* need for respiratory support, not just an acute symptom in the first week. *Presence of bilateral infiltrates on chest Xray for 2 weeks* - **Bilateral infiltrates** on a chest X-ray over two weeks could suggest conditions like **pneumonia** or **ARDS**, but it is not the diagnostic criterion for CLD. - The definition of CLD focuses on the physiological need for oxygen, rather than specific radiographic findings in isolation. *Reticulogranular pattern on chest Xray for 6 weeks* - A **reticulogranular pattern** on chest X-ray is characteristic of **respiratory distress syndrome (RDS)**, typically seen in premature infants due to surfactant deficiency. - While RDS can precede CLD, a **reticulogranular pattern** typically improves with treatment (surfactant therapy, ventilation) and does not persist for 6 weeks as a defining feature of chronic lung disease.

Question 5: In human beings, the least useful physiological response to low environmental temperature is:

A. Shivering
B. Vasoconstriction
C. Release of thyroxine
D. Piloerection (Correct Answer)

Explanation: ***Piloerection*** - **Piloerection**, or 'goosebumps,' is a vestigial reflex in humans, meaning it has lost most of its original function. - While it causes hair to stand on end, which would trap an insulating layer of air in furry animals, humans lack sufficient body hair for this to be an **effective heat retention mechanism**. *Shivering* - **Shivering** involves involuntary muscle contractions that generate heat through increased metabolic activity. - This is a highly effective and significant physiological response for **acute heat production** in response to cold. *Vasoconstriction* - **Vasoconstriction** of peripheral blood vessels reduces blood flow to the skin, thereby decreasing heat loss to the environment through conduction, convection, and radiation. - This is a crucial mechanism for **conserving core body heat** in cold conditions. *Release of thyroxine* - The **release of thyroxine** (thyroid hormone) increases the body's basal metabolic rate over a longer term, leading to increased heat production. - This is an important **adaptive response to prolonged cold exposure**, rather than an immediate one.

Question 6: Which of the following is a direct health impact of climate change?

A. Heat-related illnesses (Correct Answer)
B. Food insecurity and malnutrition
C. Injuries from extreme weather events
D. Increased vector-borne diseases

Explanation: ***Heat-related illnesses*** - Heat-related illnesses such as **heat stroke, heat exhaustion, and heat cramps** are direct health impacts of climate change resulting from increased frequency and intensity of **heat waves**. - Rising global temperatures directly increase the risk of **hyperthermia**, particularly among vulnerable populations including the elderly, children, outdoor workers, and those with chronic diseases. - This is considered a **primary direct health impact** as it results immediately from temperature changes without intermediate pathways. *Increased vector-borne diseases* - While vector-borne diseases (malaria, dengue, chikungunya) do increase with climate change due to expanded geographic range and breeding seasons of vectors, this is considered an **indirect health impact**. - Climate change affects vector ecology through temperature, rainfall, and humidity changes, which then influences disease transmission - involving an intermediate biological pathway. *Food insecurity and malnutrition* - Food insecurity and malnutrition are significant health consequences of climate change but are classified as **indirect impacts**. - They result from climate change effects on **agricultural productivity**, crop yields, food distribution systems, and water availability - multiple intermediate pathways exist between climate change and the health outcome. *Injuries from extreme weather events* - While injuries and deaths from extreme weather events (floods, cyclones, droughts) are important health impacts of climate change, they are often categorized differently from heat-related illnesses. - Heat-related illnesses represent the most **direct physiological response** to the primary manifestation of climate change (rising temperatures), making it the best answer for a "direct" health impact.

Question 7: The difference between the incidence in the exposed and non-exposed group is best given by:

A. Attributable risk (Correct Answer)
B. Population attributable risk
C. Odds ratio
D. Relative risk

Explanation: ***Attributable risk*** - **Attributable risk** (AR), also known as risk difference, directly quantifies the absolute difference in disease incidence between an **exposed group** and an **unexposed group**. - It represents the amount of disease incidence (or risk) in the exposed group that is **directly attributable to the exposure**, assuming a causal relationship. *Population attributable risk* - **Population attributable risk** (PAR) measures the proportion of disease incidence in the **total population** that is attributable to the exposure. - It takes into account both the impact of the exposure and the **prevalence of the exposure** in the population, which is distinct from simply comparing exposed and non-exposed groups. *Odds ratio* - The **odds ratio** (OR) is a measure of association between an exposure and an outcome, representing the **odds of an outcome occurring in the exposed group** compared to the odds of it occurring in the unexposed group. - It does not directly express the difference in incidence but rather the **ratio of odds**, often used in case-control studies. *Relative risk* - **Relative risk** (RR), or risk ratio, is the ratio of the **incidence of an outcome in the exposed group** to the incidence in the unexposed group. - It indicates how many times more likely an exposed group is to develop the outcome compared to an unexposed group, expressing a **ratio rather than a difference**.

Question 8: Which of the following statements is TRUE regarding Disability-Adjusted Life Year (DALY)?

A. Years lost due to disability (YLD) are not considered in DALY.
B. DALY only measures mortality and does not include morbidity.
C. DALY does not account for both YLD and YLL.
D. DALY includes both Years of Life Lost (YLL) and Years Lived with Disability (YLD). (Correct Answer)

Explanation: ***DALY includes both Years of Life Lost (YLL) and Years Lived with Disability (YLD).*** - This statement is **correct**. The fundamental formula is **DALY = YLL + YLD**. - **YLL (Years of Life Lost)** quantifies the burden of premature mortality by measuring years of potential life lost due to early death. - **YLD (Years Lived with Disability)** quantifies the burden of morbidity by measuring time lived in states of less than full health. - **DALY** is a comprehensive health metric designed to capture the total burden of disease by integrating both mortality and morbidity components. - This unified metric allows comparison of disease burden across different conditions and populations. *Years of Life Lost (YLL) is not included in DALY calculations.* - This is **incorrect**. YLL is a core component of DALY calculations, representing the mortality burden. *Years lost due to disability (YLD) are not considered in DALY.* - This is **incorrect**. YLD is an essential component of DALY, representing the morbidity burden. *DALY only measures mortality and does not include morbidity.* - This is **incorrect**. DALY explicitly measures both mortality (through YLL) and morbidity (through YLD), making it a comprehensive burden of disease measure.

Question 9: A drug used in a patient with increased IOP, optic disc changes, and ciliary congestion that acts by increasing uveoscleral outflow to decrease IOP is:

A. Latanoprost (Correct Answer)
B. Pilocarpine
C. Dorzolamide
D. Timolol

Explanation: **Latanoprost** * **Latanoprost** is a **prostaglandin analog** that effectively lowers intraocular pressure (IOP) primarily by increasing **uveoscleral outflow** of aqueous humor. * This mechanism makes it a first-line treatment for conditions like **open-angle glaucoma** and ocular hypertension, which present with increased IOP and optic disc changes. *Pilocarpine* * **Pilocarpine** is a **cholinergic agonist** that decreases IOP primarily by causing **miosis** and facilitating aqueous humor outflow through the **trabecular meshwork**. * While it lowers IOP, its mechanism is different, and it is less commonly used as a first-line agent due to side effects like **brow ache** and **visual blur**. *Dorzolamide* * **Dorzolamide** is a **carbonic anhydrase inhibitor** that reduces IOP by decreasing the **production of aqueous humor** in the ciliary body. * It does not increase uveoscleral outflow and works through a different mechanism to achieve IOP reduction. *Timolol* * **Timolol** is a **beta-blocker** that lowers IOP by decreasing the **production of aqueous humor**. * Like dorzolamide, its primary mechanism is to inhibit aqueous humor secretion rather than enhancing uveoscleral outflow.

Question 10: In a patient who has been in a state of starvation for 72 hours, which of the following is the primary mechanism for maintaining blood glucose levels?

A. Increased gluconeogenesis (Correct Answer)
B. Increased protein degradation
C. Increased glycogenolysis
D. Increased ketosis due to breakdown of fats

Explanation: ***Increased gluconeogenesis*** - After 72 hours of starvation, **hepatic glycogen stores** are completely depleted, making gluconeogenesis the primary and essential mechanism to maintain **blood glucose levels**. - This process synthesizes glucose from non-carbohydrate precursors like **amino acids** (mainly alanine and glutamine), **lactate**, and **glycerol** to supply glucose for obligate glucose-dependent tissues like **red blood cells** and the **renal medulla**, and provides baseline glucose for the brain. - Gluconeogenesis occurs primarily in the **liver** and to a lesser extent in the **kidney cortex** during prolonged fasting. *Increased protein degradation* - While **protein degradation** does occur to supply amino acids for gluconeogenesis, the body actively minimizes this to preserve muscle mass, especially after prolonged starvation. - The initial phase of starvation (first 24-48 hours) sees more significant protein breakdown, but its rate decreases substantially after 72 hours as the body becomes increasingly **protein-sparing** and shifts to fatty acid oxidation and ketone body production. *Increased glycogenolysis* - **Hepatic glycogen stores** are typically depleted within **12-24 hours** of starvation. - After 72 hours, there is essentially no glycogen remaining to break down, so **glycogenolysis** cannot contribute to maintaining blood glucose at this stage. *Increased ketosis due to breakdown of fats* - **Ketosis** does dramatically increase after 72 hours of starvation as the body shifts to using **fatty acids** for energy and producing **ketone bodies** (β-hydroxybutyrate and acetoacetate) for the brain and other tissues. - However, while ketone bodies serve as an alternative fuel source for the brain (providing up to 60-70% of its energy needs), they **cannot replace glucose entirely** because certain tissues (red blood cells, renal medulla) are obligate glucose users and cannot utilize ketones. - The question specifically asks about maintaining **blood glucose levels**, which requires gluconeogenesis, not ketone production.

Want unlimited practice?

Get full access to all questions, explanations, and performance tracking.

Start For Free