Paper II — 2025 March (Supplementary (SAY)) (2019 Scheme) — Q2
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Paper II
2025 March (Supplementary (SAY)) (2019 Scheme) · 100 marks · 180 min
Question
A 40-year-old previously healthy adult, presented to the medicine outpatient department with
malaise, fatigue, low grade fever, nausea and aversion to food. She complains of itching all over
the body. She provides history of multiple blood transfusions following a road traffic accident
eight months ago. The anti HBc IgM was positive. AST and ALT (Liver enzyme
(a) What is the probable clinical diagnosis
(b) What is the source of infection in this patient. Name other modes of transmission of this
infectious agent.
(c) Enumerate the serological markers in different phases of this infection, support with
appropriate diagrams.
(d) Write on a note on prevention of this infection (1+3+3+3)
(PTO)
Question numbers xi – xv are single response types
xi. An example for bile stained eggs in the wet mount of stool specimen
(a) Enterobius vermicularis
(b) Hook worm
(c) Ascaris lumbricoides
(d) HHymenolepis.
xii. Residents from a slum, develop fever on and off followed by jaundice after recent floods. The
most probable zoonotic infection is
(a) Enteric fever
(c) Enterically transmitted hepatitis
(b) Leptospirosis
(d) Yellow fever
xiii. Most common cause for vaccine preventable, vector borne encephalitis among children in Asia
(a) Herpes simplex encephalitis
(c) Rabies encephalitis
(b) Dengue encephalitis
(d) Japanese B encephalitis
xiv. A 32 year old was admitted with features of severe dehydration following loose stools, rice
water in nature, for the past two days. Hanging drop examination of the stool was positive for
darting motility. Name the enrichment medium used to transport the stool sample
(a) Thioglycollate broth
(c) Alkaline peptone water
(b) Selenite F broth
(d) Amies medium
xv. The viral causative agent of gastroenteritis, for which an effective vaccine is available is
(a) Norovirus
(b) Adenovirus
(c) Rotavirus
(d) Astrovirus
Question numbers xvi – xx consists of two Statements-Assertion (A) and Reason (R). Answer
these questions by selecting the appropriate options given below.
xvi. A: Naegleria fowleri causes secondary amoebic meningo encephalitis
R: The free living amoeba enters the central nervous system through the nose and cribriform
plate.
(a) Both A and R are true and R is the correct explanation of A
(c) A is true but R is false
(b) Both A and R are true and R is not the correct explanation of A
(d) A is false but R is true
xvii. A: Beta lactam antibiotics do not act against Chlamydiae pneumoniae
R: Chlamydiae pneumonia lacks a cell wall
(a) Both A and R are true and R is the correct explanation of A
(c) A is true but R is false
(b) Both A and R are true and R is not the correct explanation of A
(d) A is false but R is true
xviii. A: Bacterial meningitis due to Haemophilus influenza, among children is preventable
R: A live attenuated vaccine is invluded in the National immunization schedule
(a) Both A and R are true and R is the correct explanation of A
(c) A is true but R is false
(b) Both A and R are true and R is not the correct explanation of A
(d) A is false but R is true
xix. A: Acute rheumatic fever is one of the sequelae of sore throat caused by Streptococcus
pyogenes
R: The patient will require prophylaxis with penicillin to prevent rheumatic heart disease
(a) Both A and R are true and R is the correct explanation of A
(c) A is true but R is false
Q210 marksEssays
Answer
(a) Probable clinical diagnosis: Acute Hepatitis B virus infection — malaise, fatigue, low-grade fever, nausea, anorexia, and generalized pruritus (itching, a recognized feature of cholestatic/hepatic dysfunction), together with a positive IgM anti-HBc (the specific marker of recent/acute infection) and elevated liver enzymes, in a patient with a plausible parenteral exposure history.
(b) Source of infection and other modes of transmission: the source in this patient is most likely the multiple blood transfusions received eight months ago (a plausible incubation period for HBV, which typically ranges 45–180 days) — i.e., transfusion-transmitted infection, assuming the transfused blood/blood products were not adequately screened. Other modes of transmission of HBV: sexual contact, perinatal (vertical) transmission from an infected mother to her infant during childbirth (the most important route globally in high-endemicity settings), and other parenteral routes (needle-sharing among injection drug users, unsafe injection practices, needle-stick injury, sharing of razors/toothbrushes with an infected individual).
(c) Serological markers in different phases:
Incubation/early acute phase: HBsAg appears first, followed shortly by HBeAg (marker of active viral replication/high infectivity); HBV DNA is detectable.
Acute phase (symptomatic, as in this patient): HBsAg remains positive; IgM anti-HBc appears and is diagnostic of recent/acute infection (as positive in this patient); HBeAg typically still positive.
“Window period”: HBsAg has become undetectable, but anti-HBs has not yet appeared — IgM anti-HBc is the only detectable marker during this interval, making it essential for diagnosis at this specific phase.
Recovery/resolved infection: anti-HBs appears (indicating immunity), IgG anti-HBc persists (indicating past infection), HBsAg and HBeAg become undetectable, and anti-HBe appears (seroconversion, indicating reduced replication).
Chronic infection (if it develops instead of resolution): HBsAg persists beyond 6 months, with IgG anti-HBc positive but IgM anti-HBc negative, and HBeAg/anti-HBe status and HBV DNA level reflecting the phase of chronic infection (immune-tolerant, immune-active, inactive carrier, etc.).
(A schematic diagram of this sequence — HBsAg rising first, followed by symptoms/ALT elevation, IgM anti-HBc appearing at symptom onset, HBeAg declining with anti-HBe seroconversion, and finally anti-HBs appearing after HBsAg clears, with the “window period” gap between HBsAg disappearance and anti-HBs appearance — would normally accompany this answer as a labelled time-course graph; described here in text form as diagrams cannot be rendered in this format.)
(d) Prevention:
Active immunization — Hepatitis B vaccine (recombinant HBsAg subunit vaccine), part of the routine infant immunization schedule (including a birth dose), and available for at-risk adults/healthcare workers.
Passive immunization — Hepatitis B Immunoglobulin (HBIG), for post-exposure prophylaxis (e.g., needle-stick injury in a susceptible individual, or neonates born to HBsAg-positive mothers, given within 12–24 hours of birth alongside the vaccine birth dose).
Screening of blood/blood products before transfusion — directly relevant to this patient’s likely source of infection, underscoring the importance of rigorous blood-bank screening protocols.
Safe injection practices, avoidance of needle-sharing, and safe sexual practices (condom use) to reduce parenteral and sexual transmission.
General precautions — avoiding sharing of personal items (razors, toothbrushes) that may carry blood contamination.
