Communicable Diseases (Malaria, Tuberculosis, Dengue, Polio, Hepatitis, Cholera) MCQs

Community Medicine (PSM) · 197 free questions with answers & explanations.

1. A patient presents with high-grade fever, intense headache, retroorbital pain, myalgia, and a characteristic skin rash appearing on day 3-4. Tourniquet test is positive. Which serological test confirms the diagnosis of dengue during the acute febrile phase (days 1-5)?
2. In malaria control under NVBDCP, indoor residual spraying (IRS) with DDT is still used in India. The primary mechanism by which IRS reduces malaria transmission is:
3. A 35-year-old male is found to have HBsAg positive, anti-HBe positive, HBeAg negative, and HBV DNA of 12,000 IU/mL with ALT twice the upper limit of normal. This serological pattern is most consistent with which phase of HBV infection?
4. India was certified polio-free by WHO in March 2014. The global strategy to achieve polio eradication now includes using novel oral polio vaccine type 2 (nOPV2) after a circulating vaccine-derived poliovirus type 2 (cVDPV2) outbreak. Which best explains why monovalent OPV type 2 was removed from the routine NIS?
5. During an outbreak investigation of acute watery diarrhoea in a village following flooding, stool cultures yield comma-shaped, gram-negative organisms growing on TCBS medium producing yellow colonies. Which species is most likely?
6. Under NVBDCP's National Framework for Malaria Elimination 2016–2030, districts with Annual Parasite Incidence (API) greater than which threshold are designated High Endemic Districts requiring intensified vector control?
7. Dengue confirmed by NS1 antigen or IgM ELISA is notified in India through which form of the Integrated Disease Surveillance Programme (IDSP)?
8. India switched from tOPV to bOPV in April 2016. The primary reason for this switch was:
9. A patient presents with high fever (40°C), retroorbital pain, severe headache, myalgia, and a petechial rash on day 5 of illness. Platelet count is 42,000/mm³. NS1 antigen is positive. According to WHO dengue classification (2009), this case should be classified as:
10. In the context of polio eradication, India was certified polio-free in 2014. The current strategy includes Inactivated Polio Vaccine (IPV). The rationale for introducing fractional dose IPV (fIPV) intradermally is:
11. A drug-resistant TB patient is identified with resistance to Rifampicin on Xpert MTB/RIF. As per current NTEP guidelines, the next diagnostic step before initiating regimen is:
12. The El Tor biotype of Vibrio cholerae O1 which caused the 7th pandemic has a characteristic that distinguishes it from the Classical biotype in terms of clinical presentation and cultural characteristics. Which of the following is CORRECT about El Tor biotype?
13. A traveller returning from sub-Saharan Africa presents with high-grade fever, chills, headache, and splenomegaly. Blood smear shows 'banana-shaped' gametocytes. Which complication is this patient most at risk of, and what urgent investigation should be prioritized?
14. Regarding hepatitis E infection, which of the following statements is correct regarding its peculiar severity in a specific population?
15. In the WHO dengue classification (2009), a patient presenting with fever, abdominal pain, persistent vomiting, clinical fluid accumulation, and platelet count 85,000/mm³ is classified as:
16. The secondary attack rate (SAR) of cholera in a household is 40%. This means:
17. In the hepatitis B vaccination programme, the efficacy of the vaccine is determined by checking anti-HBs antibody titer 1 month after the third dose. The protective antibody level is considered adequate if anti-HBs is:
18. A 35-year-old presents with fever for 5 days, severe thrombocytopenia (platelets 18,000/µL), petechiae, and a positive tourniquet test. NS1 antigen is positive on day 3. On day 6, the patient develops dengue hemorrhagic fever grade III. The primary pathophysiologic mechanism is:
19. Oral cholera vaccine (OCV) Shanchol is used in India for outbreak control. Which of the following BEST describes the schedule for use in mass vaccination campaigns?
20. Poliovirus type 2 was declared eradicated globally in 2015, yet type 2-containing Oral Polio Vaccine (tOPV) was withdrawn in 2016. The PRIMARY reason for tOPV withdrawal and switch to bOPV was:
21. A 32-year-old returns from a forested area in Odisha with fever for 3 days, headache, and mild confusion. Blood smear shows ring forms with double chromatin dots and banana-shaped gametocytes. Which characteristic of the causative organism best explains the cerebral manifestations?
22. In the context of the WHO's End TB Strategy, India aims to eliminate tuberculosis by what year, and at what target threshold?
23. During a dengue outbreak, NS1 antigen is positive on Day 2 of fever. On Day 8, the appropriate diagnostic test to confirm dengue is:
24. The 'sero-type switching' phenomenon in dengue is clinically significant because:
25. Cholera toxin produces profuse rice-water diarrhoea by which specific mechanism?
26. A cluster of 12 cases of acute watery diarrhoea occurs in a village within 24–48 hours of a community feast. Vibrio cholerae O1 Ogawa biotype El Tor is confirmed. The R₀ for cholera under these conditions is most likely in the range:
27. Under the Revised Dengue Case Classification (WHO 2009), dengue with 'warning signs' includes all of the following EXCEPT:
28. Dracunculus medinensis (Guinea worm) eradication relies primarily on which intervention, given the absence of any drug treatment or vaccine?
29. Regarding Polio Eradication in India (certified wild poliovirus-free since January 2014), which surveillance indicator is used to assess the quality of AFP surveillance?
30. In NTEP, a patient with drug-susceptible TB (DS-TB) who is smear-positive at the end of 2 months of intensive phase is said to have:
31. A cluster of dengue cases occurs in an urban area. The entomological index most sensitive for detecting low-level Aedes aegypti infestation in urban areas is:
32. In the context of polio eradication, a case of acute flaccid paralysis (AFP) is classified as 'compatible with polio' when:
33. The El Tor biotype of Vibrio cholerae O1, which currently causes most cholera outbreaks worldwide, differs from the classical biotype in that it:
34. In the Hepatitis B epidemiology, the predominant mode of transmission in an area with HBsAg carrier rate of 10-15% in the general population (hyperendemic area like South-East Asia) is:
35. In the WHO classification of dengue (2009 revised guidelines), 'dengue with warning signs' includes all of the following EXCEPT:
36. A village in a high-malaria-burden district shows high rates of P. falciparum. The district malaria officer decides to deploy Long Lasting Insecticidal Nets (LLINs). According to NVBDCP norms, LLINs need re-treatment or replacement approximately every:
37. A district health officer receives a report of a child with Vaccine Derived Poliovirus (VDPV) type 2. The child received bOPV (bivalent oral poliovirus vaccine) as per schedule. What is the MOST likely source of this VDPV2?
38. Hepatitis E virus (HEV) causes high mortality specifically in which population group, and what is the approximate case-fatality rate in that group?
39. The El Tor biotype of Vibrio cholerae O1 has undergone genetic changes producing the 'altered El Tor' or 'hybrid El Tor' variant. What is the hallmark of this variant compared to classical El Tor?
40. In a district with P. falciparum malaria, the Annual Blood Examination Rate (ABER) is 12% and Slide Positivity Rate (SPR) is 2.5%. Based on these indices, the malaria burden classification and surveillance adequacy are:
41. A 28-year-old IVDAs tests positive for HBsAg. His HBeAg is negative, anti-HBe positive, HBV DNA is 22,000 IU/mL and ALT is elevated. This serological profile is consistent with:
42. Dengue NS1 antigen detection is most useful diagnostically in which phase of the illness?
43. El Tor biotype of Vibrio cholerae O1 produces a milder disease than classical biotype. The molecular reason for milder disease in El Tor is:
44. G6PD deficiency testing is MANDATORY before administering which antimalarial drug used in the NVBDCP programme?
45. A 7-year-old boy in a remote village develops acute flaccid paralysis of the left lower limb without fever, 5 days after receiving the oral poliovirus vaccine during a pulse immunization campaign. The limb shows hyporeflexia and asymmetric weakness. Which VAPP-specific criterion makes vaccine-associated paralytic poliomyelitis most likely?
46. The WHO-defined Acute Flaccid Paralysis (AFP) surveillance case definition used in the Pulse Polio Programme includes which age group for mandatory reporting?
47. In dengue, the 'tourniquet test' (Rumpel-Leede phenomenon) is performed by inflating a blood pressure cuff to the midpoint between systolic and diastolic pressure for 5 minutes. A positive test is defined as:
48. Cholera toxin's mechanism of action results in the characteristic 'rice-water' diarrhoea. The toxin activates adenylate cyclase by ADP-ribosylation of which G-protein subunit?
49. A district health officer reports that the Slide Positivity Rate (SPR) for malaria in her district has crossed 5% for three consecutive months. According to NVBDCP operational guidelines, this indicates:
50. A patient presents with dengue fever. On Day 3 of illness, the dengue NS1 antigen rapid test is positive. On Day 8, dengue IgM and IgG serology is sent. Which combination correctly represents secondary dengue infection serology?
51. India uses the Environmental Surveillance (ES) system for poliovirus detection in sewage. A positive ES sample from an urban site is best described as evidence of:
52. Circulating Vaccine-Derived Poliovirus type 2 (cVDPV2) caused outbreaks in several African countries after OPV2 removal from routine schedules in 2016. India uses novel OPV2 (nOPV2) in outbreak response since 2021. Which property of nOPV2 distinguishes it from the classical Sabin type 2 strain?
53. In Dengue, the 'NS1 antigen test' detects non-structural protein 1, which is secreted abundantly during early dengue infection. In a patient presenting on Day 5 of fever with platelet count 85,000/µL, which combination of diagnostic tests has the HIGHEST combined sensitivity?
54. India declared cholera elimination from endemic transmission as a target for 2030 under the Global Roadmap to End Cholera. Regarding the oral cholera vaccine (OCV) used in India's outbreak response, which statement is CORRECT?
55. In type III dengue outbreak investigation, a cluster of haemorrhagic dengue cases appears in an urban ward. The entomological index most strongly associated with epidemic risk in urban Aedes aegypti settings is:
56. The Revised Vibrio cholerae case definition under IDSP classifies a case as 'confirmed' when:
57. The concept of 'poliovirus environmental surveillance' (sewage surveillance) detects poliovirus in wastewater before clinical cases appear. The critical advantage of this approach over AFP (Acute Flaccid Paralysis) surveillance is:
58. In the epidemiology of dengue fever, 'secondary infection' by a heterologous dengue serotype is associated with severe dengue (dengue haemorrhagic fever/dengue shock syndrome) through which mechanism?
59. India achieved WHO certification for polio-free status in March 2014. Which poliovirus type was the LAST to be eliminated from India before certification?
60. In a cholera outbreak investigation, the attack rate in a community is calculated. Among 400 people who attended a feast and drank contaminated water, 80 developed cholera; among 600 who did not drink the water, 6 developed cholera. The Relative Risk (RR) of cholera associated with drinking contaminated water is approximately:
61. In the malaria transmission cycle, the extrinsic incubation period (EIP) of Plasmodium falciparum in Anopheles mosquito at 25°C is approximately:
62. An outbreak investigation of hepatitis E reveals a large common-source waterborne outbreak. Which epidemiological feature of hepatitis E BEST distinguishes it from hepatitis A in outbreak settings?
63. A district has reported 500 new smear-positive TB cases in year 1 and 450 in year 2 from a population of 500,000. Which indicator directly measures the programme performance regarding detection of existing TB cases?
64. In dengue pathogenesis, which immunological mechanism best explains why secondary infection with a heterologous dengue serotype causes more severe disease (dengue haemorrhagic fever/dengue shock syndrome)?
65. El Tor biotype of Vibrio cholerae O1 has largely replaced Classical biotype worldwide. Compared to Classical, El Tor is characterised by which combination of features?
66. A 38-year-old tribal woman in Odisha presents with high-grade fever, jaundice, and altered sensorium 10 days after entering a forest area for collection. Blood smear shows ring forms and banana-shaped gametocytes. She is 14 weeks pregnant. Which antimalarial regimen is MOST appropriate?
67. In dengue surveillance, the 'warning signs' that indicate possible severe dengue and require inpatient observation include all EXCEPT:
68. India was certified polio-free in 2014. The Global Polio Eradication Initiative currently uses bivalent oral polio vaccine (bOPV) and not trivalent OPV. The reason type 2 component was withdrawn from routine OPV is:
69. A food inspector tests water samples from a town's piped supply. Bacteriological examination shows a Most Probable Number (MPN) of E. coli at 18/100 mL. According to WHO and Indian standards for potable water, this sample is:
70. In the context of polio surveillance, 'Acute Flaccid Paralysis (AFP) surveillance' uses a minimum target rate. The WHO-recommended AFP surveillance target rate (non-polio AFP rate) is at least:
71. In dengue, the WHO 2009 classification replaced the older DHF grading and introduced a new category. A dengue patient with severe plasma leakage causing respiratory distress and requiring mechanical ventilation is classified as:
72. During a cholera outbreak investigation, the attack rate in a community consuming water from Source A is 12% and from Source B is 3%. The relative risk (RR) of cholera associated with Source A versus Source B is:
73. The 'basic reproduction number' (R₀) of a pathogen represents the average number of secondary cases generated by one infectious case in a fully susceptible population. If the herd immunity threshold (HIT) for measles is approximately 95%, the corresponding R₀ value is:
74. A 28-year-old woman from Assam presents with fever for 5 days, altered sensorium, and jaundice. Her rapid diagnostic test (RDT) is positive for P. falciparum. Peripheral smear shows >5% parasitised RBCs. Which criterion ALONE qualifies this as severe malaria?
75. In 2023, India achieved wild poliovirus-free certification in 2014 but maintains surveillance using Acute Flaccid Paralysis (AFP) surveillance. The minimum stool sample adequacy criterion for AFP surveillance is:
76. El Tor biotype of Vibrio cholerae O1 differs from Classical biotype in all of the following EXCEPT:
77. The 'SPAR' (State Party Annual Report) under IHR 2005 assesses national core capacities for health security. India's index 2023 shows strength in which of these domains as per recent assessment?
78. A 38-year-old male presents with high fever, severe retro-orbital pain, myalgia, and a maculopapular rash on day 5. Platelet count is 60,000/μL, NS1 antigen is positive. The most sensitive test to confirm dengue infection in the first 5 days of illness is:
79. Vibrio cholerae O139 Bengal differs from O1 El Tor in that it:
80. In the Global Polio Eradication Initiative (GPEI), the switch from trivalent OPV (tOPV) to bivalent OPV (bOPV) occurred in April 2016 because:
81. The secondary attack rate (SAR) of measles in susceptible household contacts is approximately:
82. Hepatitis E virus (HEV) genotypes 1 and 2 are predominantly associated with waterborne epidemic transmission. Hepatitis E in pregnant women is particularly dangerous because it causes:
83. The 'slide positivity rate' (SPR) in malaria surveillance differs from 'slide falciparum rate' (SFR) in that:
84. The 'generation time' in infectious disease epidemiology is best defined as:
85. Under India's Integrated Disease Surveillance Programme (IDSP), syndromic case definitions are used. Which category of reporting is done weekly via the 'W' form?
86. Dengue haemorrhagic fever (DHF) progresses through three phases. The phase characterised by spontaneous bleeding, thrombocytopenia <100,000/µL, and leakage of plasma into the third space with haemoconcentration is:
87. Plasmodium vivax malaria can cause relapses months to years after the primary infection due to dormant liver-stage parasites called hypnozoites. The only licensed drug active against hypnozoites to prevent relapse is:
88. The El Tor biotype of Vibrio cholerae O1, the dominant biotype responsible for the 7th pandemic, has been observed to acquire classical biotype characteristics including production of classical CT (cholera toxin). These are called:
89. In the context of polio eradication, Vaccine-Associated Paralytic Poliomyelitis (VAPP) is most commonly associated with which OPV serotype?
90. Under the WHO-recommended Integrated Management of Childhood Illness (IMCI), a child with malaria residing in high-transmission area and found to have axillary temperature ≥37.5°C should first receive:
91. During a dengue outbreak investigation, a seroepidemiological survey finds that the proportion of immune individuals in the community is 70%. The basic reproduction number (R0) of dengue in this area is estimated at 4. The additional proportion of the population that still needs to become immune to reach the Herd Immunity Threshold is:
92. An outbreak of watery diarrhoea affects villagers who consumed water from a common well. Stool cultures grow Vibrio cholerae O1 biotype El Tor, serotype Ogawa. The MOST critical public health intervention to interrupt transmission at the population level is:
93. India achieved polio-free certification in 2014. The 'Polio Endgame Strategy' required switching from trivalent OPV (tOPV) to bivalent OPV (bOPV) plus IPV. The primary reason for introducing at least one dose of IPV into the schedule was to:
94. A 32-year-old healthcare worker receives post-exposure prophylaxis (PEP) after a needlestick injury from an HBsAg-positive patient. She was previously vaccinated with 3-dose HBV vaccine series but never had a post-vaccination anti-HBs titre checked. The recommended management is:
95. A 32-year-old man from Odisha returns from a forest area with fever for 5 days. Thick blood smear shows banana-shaped gametocytes. He is prescribed artesunate-based therapy. Two weeks later he develops haemoglobinuria and acute kidney injury. The drug MOST likely responsible is:
96. During a village cholera outbreak investigation, the attack rate in those who ate food at a community feast is 18/120 and in those who did not eat at the feast is 2/80. What is the Relative Risk (RR) of developing cholera with feast attendance?
97. A state health department declares a dengue outbreak. The primary vector Aedes aegypti is found breeding predominantly in artificial containers indoors. Which vector control method targets immature stages (larvae and pupae) in domestic water containers and is the MOST appropriate for rapid containment?
98. Environmental surveillance for poliovirus in India uses sewage samples from select sites as an early warning system. This is known as:
99. A district public health officer receives a report of a jaundice cluster affecting 45 individuals who consumed water from the municipal supply. Anti-HAV IgM is positive in 38 of the 45 cases. The MOST likely mode of transmission and the water source implicated is:
100. A 28-year-old man presents with fever, headache and petechiae. Dengue NS1 antigen is positive on day 2 of fever. His platelet count is 85,000/µL. The MOST appropriate management at this stage is:
101. Oral Cholera Vaccine (OCV) used in India under emergency situations is a killed whole-cell vaccine. The schedule for adults in a reactive vaccination campaign is:
102. Which of the following is a reliable indicator that a village is at high risk for a malaria outbreak, used under NVBDCP surveillance?
103. A Type II AFP (Acute Flaccid Paralysis) case in a child under 15 years must have stool specimens collected within how many days of AFP onset for adequate poliovirus surveillance?
104. Which serological marker is the FIRST to appear during acute Hepatitis B infection and is also present in chronic carriers?
105. A 30-year-old woman presents with high-grade fever, severe headache, and altered sensorium. Blood smear shows P. falciparum rings. She has no history of quinine intake. Her blood glucose is 1.8 mmol/L. Which of the following CORRECTLY explains the mechanism of hypoglycemia in this case?
106. Dengue hemorrhagic fever (DHF) is graded I–IV. A patient with dengue presents with spontaneous bleeding from the gums, thrombocytopenia (platelet count 55,000/µL), and a positive tourniquet test. There is no circulatory failure. This corresponds to DHF Grade:
107. In the context of polio eradication, which of the following correctly describes the biological basis for Vaccine-Associated Paralytic Poliomyelitis (VAPP)?
108. El Tor biotype of Vibrio cholerae, which caused the 7th pandemic, differs from classical biotype in which of the following characteristics?
109. Kala-azar (visceral leishmaniasis) elimination target set by India is defined as reducing the annual incidence to below which threshold per 10,000 population at the sub-district (block/taluka) level?
110. A patient from Jharkhand presents with fever with rigors, splenomegaly, and a peripheral smear showing banana-shaped gametocytes. The drug of choice for treating the asexual stage of this Plasmodium species is:
111. The dengue NS1 antigen test is most useful in which phase of dengue fever for early diagnosis?
112. Mycobacterium tuberculosis transmission to close contacts is most accurately quantified by which index in epidemiological surveillance?
113. The Vi antigen polysaccharide vaccine for typhoid fever is recommended for which age group and provides protection for how long?
114. The Vibrio cholerae O1 El Tor biotype is distinguished from the classical biotype by being positive for which test?
115. A patient presents with fever for 5 days, retro-orbital pain, myalgia, and a rash. Tourniquet test is positive with 25 petechiae per square inch. Platelet count is 60,000/μL. NS1 antigen is positive on day 3. Which warning sign of severe dengue is ABSENT in this patient?
116. In the WHO classification of poliomyelitis, Acute Flaccid Paralysis (AFP) surveillance includes the collection of two stool samples. The recommended interval between the two stool samples and the ideal time for collection is:
117. El Tor biotype of Vibrio cholerae O1 differs from classical biotype in which of the following characteristics?
118. The 'End TB Strategy' target by 2030 aims to reduce TB incidence and mortality by what percentage compared to 2015 baseline?
119. Hepatitis E virus infection during pregnancy is associated with a particularly high case fatality rate especially in the third trimester. The approximate case fatality rate in pregnant women is:
120. In a dengue outbreak investigation, a patient presents on Day 3 of fever. Which combination of tests is MOST appropriate to maximise diagnostic sensitivity at this stage?
121. The World Health Organization's criteria for declaration of polio eradication requires a country to have reported no case of wild poliovirus for a minimum of how many years with adequate surveillance?
122. A 35-year-old woman is diagnosed with cholera during an outbreak in a flood-affected area. She has severe dehydration (WHO plan C). After initial IV rehydration, what is the SINGLE MOST IMPORTANT public health intervention to control the outbreak?
123. The 'Pradhan Mantri TB Mukt Bharat Abhiyan' (PMTBMBA) aims to eliminate TB in India by which target year?
124. In the classification of malaria endemicity, the Spleen Rate (SR) in children aged 2–10 years is the key indicator. A SR of 10–50% in this age group indicates:
125. Dengue haemorrhagic fever (DHF) is more commonly seen on secondary infection with a different dengue serotype. The immunological mechanism responsible is:
126. Under the Global Polio Eradication Initiative (GPEI), India was declared polio-free in 2014. However, OPV is still administered under the UIP. The primary reason for continuing OPV after wild poliovirus elimination is:
127. In an outbreak investigation of cholera, the primary case is identified and the local health authority establishes a 'containment zone'. The bacteriological confirmation of V. cholerae O1 or O139 from stool is based on growth on which selective medium?
128. The 'case fatality rate' (CFR) for untreated severe cholera (Cholera gravis) is approximately:
129. India achieved polio-free certification in 2014. The last wild poliovirus case in India was reported in:
130. During a cholera outbreak investigation, the minimum attack rate in a specific population subset exceeds 0.5% in a week. Under WHO criteria, this level of transmission in a previously unaffected area would be classified as:
131. The WHO-recommended strategy for dengue vector control that targets larval breeding sites in water storage containers is called:
132. A chest X-ray of a 30-year-old male shows a Ghon's focus with ipsilateral hilar lymphadenopathy. This radiological complex is known as:
133. India's malaria elimination target as per the National Framework for Malaria Elimination is to achieve elimination by:
134. The Epidemic Curve (Epi Curve) showing a sharp rise and fall of cases over a very short period (2-3 days), with all cases falling within one incubation period, is most consistent with:
135. Herd immunity threshold (HIT) is determined by the formula HIT = 1 − (1/R₀). For measles with R₀ = 15, the herd immunity threshold is approximately:
136. Mission Indradhanush was launched to accelerate immunization coverage in India. The Full Immunization Coverage (FIC) target under Mission Indradhanush is to achieve:
137. Hepatitis E is the most common cause of acute viral hepatitis in India. The group at highest risk of fulminant hepatic failure from Hepatitis E is:
138. In India's NVBDCP, what is the current definition of 'Annual Parasitic Incidence (API)' threshold above which a district is classified as a 'High-Burden District' for malaria?
139. Dengue Haemorrhagic Fever (DHF) grade III and IV together constitute dengue shock syndrome. According to WHO classification, which clinical feature differentiates DHF Grade II from Grade I?
140. In the context of cholera surveillance, a case is defined as a suspected case when a person aged 5 years or more develops acute watery diarrhoea with or without vomiting. Which Vibrio cholerae serogroup is responsible for the El Tor biotype currently causing pandemics?
141. In India's Polio Eradication Programme, the concept of 'Pulse Polio Immunisation (PPI)' is based on which epidemiological principle?
142. A 28-year-old healthcare worker presents 6 weeks after needlestick injury from a Hepatitis B surface antigen (HBsAg)-positive patient. She received 3 doses of recombinant Hepatitis B vaccine in the past and post-vaccination anti-HBs titer is 55 IU/L. What is the BEST management now?
143. An outbreak investigation of dengue in a village finds 3 confirmed dengue fever deaths among 50 laboratory-confirmed cases. The Case Fatality Rate (CFR) is:
144. The Vicarious Immunity in the context of polio refers to:
145. A 32-year-old pregnant woman (28 weeks gestation) presents with fever, jaundice, and coagulopathy. She belongs to a rural area with recent flooding. AST/ALT are markedly elevated. The diagnosis MOST consistent with high mortality in pregnancy is:
146. Which of the following describes the 'Singapore' strategy used for dengue vector control?
147. Environmental surveillance for poliovirus in sewage (Environmental Surveillance — ES) as part of India's Polio Eradication Program detects poliovirus in wastewater. The MOST appropriate next step is:
148. The 'Vivax package' (Primaquine 0.25 mg/kg for 14 days) for radical cure of Plasmodium vivax malaria under NVBDCP is contraindicated in which group?
149. Which of the following is the hallmark pathophysiological finding that DIFFERENTIATES dengue haemorrhagic fever (DHF) from dengue fever (DF) according to WHO classification?
150. The 'End TB Strategy' adopted by WHO in 2015 aims to reduce TB deaths by 95% and incidence by 90% compared to 2015 levels. The target year is:
151. El Tor biotype of Vibrio cholerae O1 differs from the classical biotype primarily because El Tor:
152. A village with 5000 population reports 25 new malaria cases in one month. The Annual Parasite Index (API) for this village for the year (assuming same rate throughout) would be:
153. Wild poliovirus type 2 was declared eradicated globally in which year?
154. Under NTEP, Universal Drug Susceptibility Testing (UDST) means that DST should be performed for which group?
155. Dengue NS1 antigen test is MOST useful in which window of illness?
156. In the context of malaria elimination, 'High Burden to High Impact' (HBHI) strategy has been adopted by India in its high-burden states. The 'stratification' pillar in HBHI focuses on:
157. A stool sample from a child with acute flaccid paralysis (AFP) must reach the national poliovirus laboratory within how many days of collection to be considered adequate?
158. The primary mode of transmission of Cholera (Vibrio cholerae O1 El Tor biotype) in outbreak settings is:
159. In the WHO classification of Hepatitis B serological markers, a patient shows: HBsAg negative, anti-HBs positive, anti-HBc positive (total). This pattern is MOST consistent with:
160. In a district that was recently certified as polio-free, a 4-year-old child develops acute flaccid paralysis (AFP). Stool samples are sent to the reference laboratory. Which finding would classify this as a Vaccine-Derived Poliovirus (VDPV) case rather than wild poliovirus?
161. In dengue fever, on which day of illness does thrombocytopenia typically reach its nadir and the patient is at HIGHEST risk for plasma leakage?
162. Regarding cholera surveillance in India, what is the minimum bacteriological criterion for confirming a cholera outbreak at a district level?
163. A 30-year-old male returning from a P. falciparum-endemic area has high-grade fever. His peripheral smear shows >5% parasitized red cells. According to NVBDCP criteria, this constitutes:
164. In the WHO case classification for polio surveillance, an 'AFP case with virologically confirmed poliovirus' constitutes which category?
165. Dengue serotype-specific immunity after natural infection is lifelong, but cross-serotype (heterologous) immunity is temporary. This has which important epidemiological consequence?
166. In cholera management, the WHO recommended first-line antibiotic for adult patients with severe cholera is:
167. Which of the following best defines a 'Tuberculosis Presumptive Case' under NTEP?
168. Hepatitis E virus (HEV) infection is disproportionately severe in which population, with case fatality rates of up to 20–25%?
169. In the NVBDCP National Vector Borne Disease Control Programme, an API (Annual Parasite Incidence) > 2 per 1000 population classifies a district as:
170. Reproductive number (R₀) of SARS-CoV-2 (original Wuhan strain) was approximately 2–3, while the Omicron variant had R₀ approximately 8–15. R₀ represents:
171. The National Viral Hepatitis Control Programme (NVHCP) in India aims to eliminate hepatitis B and C by 2030. Which seromarker is used to confirm 'cured' status for Hepatitis C after treatment with Direct-Acting Antivirals (DAAs)?
172. A district reports 20 cases of Japanese Encephalitis in August–September. The primary vector mosquito responsible for JE transmission in India is:
173. The 'Basic Case Reproduction Number' (R₀) of measles is approximately 12–18. After achieving 95% vaccination coverage, which threshold phenomenon explains why measles transmission is interrupted?
174. India's Integrated Disease Surveillance Programme (IDSP) reports outbreak data using which classification of alerts?
175. A community has 1000 cases of an acute febrile illness reported over 4 weeks. The attack rate in males is 30% (150/500) and in females is 10% (50/500). What is the sex-specific Relative Risk (RR) for males?
176. Sentinel surveillance in HIV is conducted at Integrated Counselling and Testing Centres (ICTCs). Which population group is classified as a 'Bridge Population' in India's NACP surveillance?
177. A district reports a 'Malarial Epidemic'. Under NVBDCP, an epidemic is declared when which criterion is met?
178. The National Viral Hepatitis Control Programme (NVHCP) was launched in 2018 with which primary target?
179. A health worker in a malaria endemic area finds a child with fever. Rapid Diagnostic Test (RDT) detects HRP2 antigen. This is specific for which Plasmodium species?
180. A 7-year-old child presents with painless ulcer on the sole of the foot, loss of sensation, and claw hand deformity. Slit-skin smear shows acid-fast bacilli with a Bacterial Index (BI) of 4+. According to the Ridley-Jopling classification, this child most likely belongs to which leprosy type?
181. A 25-year-old woman is diagnosed with smear-positive pulmonary tuberculosis. She is started on Category I DOTS therapy under the Revised National Tuberculosis Control Programme (RNTCP)/National Tuberculosis Elimination Programme (NTEP). Which of the following correctly describes the intensive phase of her treatment?
182. During a malaria survey in a district of Odisha, the following data is collected: Parasite Rate = 12%, Slide Positivity Rate = 18%, Annual Blood Examination Rate = 10%, and Annual Parasite Incidence = 8 per 1000. Based on this data, which classification best describes this district?
183. A health worker notes that a cluster of cholera cases have occurred downstream of a river, all within one week, with a common peak in the epidemic curve followed by rapid decline. What type of epidemic pattern does this most likely represent?
184. A 30-year-old HIV-positive man with CD4 count of 150 cells/mm³ develops a chronic, watery, profuse diarrhoea that is unresponsive to standard antibiotics. Stool microscopy with modified ZN stain shows small oocysts (4-6 µm). What is the most likely causative organism?
185. India launched the Pulse Polio Immunisation programme with the goal of eradicating poliomyelitis. The last case of wild poliovirus (WPV) in India was reported in 2011, and India was certified polio-free in 2014. The type of vaccination strategy that underlies Pulse Polio (National Immunization Days) is best described as:
186. The Epidemiological Triad (Host-Agent-Environment) model was replaced by the Web of Causation model proposed by:
187. During a dengue outbreak investigation, the Stegomyia (House) Index is calculated as 20%. This means:
188. The generation time of an infectious disease differs from incubation period in that it refers to:
189. In the epidemiological investigation of a foodborne outbreak in a school, the attack rate for those who ate the salad was 75% (60/80) and for those who did NOT eat the salad was 15% (6/40). The Relative Risk of illness from eating salad is:
190. A Lyme disease patient in India presents with characteristic expanding skin rash, migratory joint pain, and cardiac arrhythmia. The vector responsible for transmission is:
191. A district reports a measles outbreak despite 92% measles vaccination coverage. The MOST likely explanation is:
192. Pulse Polio Immunisation (PPI) uses oral polio vaccine (OPV) in mass campaigns. The strategy of simultaneous vaccination of all children under 5 years regardless of prior immunisation status achieves eradication by:
193. The RNTCP/NTEP defines a 'Lost to Follow-up' (previously 'default') TB patient as one who has:
194. A study reports a Pearson correlation coefficient (r) of -0.78 between daily aerobic exercise minutes and fasting blood glucose in diabetic patients. The BEST interpretation is:
195. In survival analysis, the Kaplan-Meier estimator is used to plot survival curves. 'Censored' observations are those where:
196. A logistic regression model is used to analyse risk factors for pre-eclampsia. The adjusted odds ratio for nulliparity is 2.8 (95% CI: 1.6–4.9, p=0.0003). This means:
197. A new diagnostic test for active pulmonary TB is evaluated in a tertiary hospital (high disease prevalence = 30%) and a primary care centre (low prevalence = 5%). The test has fixed sensitivity of 85% and specificity of 90%. Where will the Positive Predictive Value (PPV) be HIGHER?