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MI4.1-9 | Gastrointestinal & Hepatobiliary Infections — Case Study
CLINICAL SCENARIO
An antenatal clinic in a district hospital in Tamil Nadu identifies three pregnant women with abnormal liver function tests during routine screening. You are the duty medical officer and must interpret the hepatitis serology panel, determine the diagnosis, assess infectivity and risk, and outline clinical management for each case.
Instructions
Scenario
Three women present for antenatal check-up at 28 weeks of pregnancy. Routine serology reveals the following panels:
| Marker | Mrs A | Mrs B | Mrs C |
|---|---|---|---|
| HBsAg | Positive | Negative | Negative |
| Anti-HBs | Negative | Positive | Negative |
| Anti-HBc IgM | Negative | Negative | Positive |
| Anti-HBc IgG | Positive | Negative | Negative |
| HBeAg | Positive | — | — |
| Anti-HBe | Negative | — | — |
| HBV DNA | 8,000,000 IU/mL | — | — |
| Anti-HAV IgM | Negative | Negative | Negative |
| Anti-HEV IgM | Negative | Negative | Positive |
| ALT | 85 U/L | Normal | 320 U/L |
Task
Write a structured clinical report (600–800 words) addressing all four sections below. Use the serology data and your knowledge of hepatitis virology and epidemiology to support each answer.
### Section 1: Diagnosis and Serological Interpretation
For each woman (Mrs A, Mrs B, Mrs C), state the diagnosis, justify it with the specific marker pattern, and identify any gaps or next steps in serological workup.
### Section 2: Infectivity Assessment and Vertical Transmission Risk
For Mrs A and Mrs C, discuss the risk to the unborn child, the mechanism of vertical transmission, and the specific virological marker that quantifies risk.
### Section 3: Immediate Clinical Management
Outline the management of each case, including referral, prophylactic/therapeutic interventions, and counselling points. Apply current NMC CBME-aligned clinical guidelines.
### Section 4: Preventive Strategies and Public Health Response
Discuss how a district hospital can systematically prevent perinatal hepatitis B and waterborne HEV. Include vaccination schedules, birth prophylaxis, and the rationale for screening pregnant women.
Length: 600-800 words
What to Submit
Section 1: Diagnosis and Serological Interpretation (approx. 180 words)
For each woman, name the diagnosis and cite the specific marker(s) that establish it. For Mrs A: address the significance of HBsAg positivity, HBeAg, anti-HBe, and HBV DNA together. For Mrs B: explain why anti-HBs alone without anti-HBc indicates vaccination. For Mrs C: explain the window period (HBsAg negative + anti-HBc IgM + anti-HEV IgM positive) — is more than one hepatitis virus implicated?
Guidance: Be precise with marker interpretation: anti-HBc IgM = acute/window; anti-HBc IgG alone = past infection or window; anti-HBs alone = vaccinated; HBeAg + high HBV DNA = high replication and infectivity.
Section 2: Infectivity Assessment and Vertical Transmission Risk (approx. 160 words)
For Mrs A (chronic HBV, HBeAg+, HBV DNA 8M IU/mL): state the vertical transmission risk as a percentage, explain the mechanism (intrapartum blood/fluid exposure vs. transplacental), and identify the most important single marker predicting neonatal infection. For Mrs C (acute HBV window + HEV): address HEV-specific risk in the third trimester (case fatality rate) and whether HEV transmits vertically.
Guidance: HBeAg-positive mothers with high viral load carry up to 90% risk of neonatal chronicity. HEV genotype 1 has 20–25% case fatality in third-trimester pregnancy and can transmit vertically, causing neonatal HEV.
Section 3: Immediate Clinical Management (approx. 200 words)
Mrs A: What antiviral therapy (if any) should be considered in the third trimester? What MUST be done within 12 hours of delivery for the neonate? Mrs B: Any action needed? Mrs C: Identify which hepatitis needs management urgency. Is there specific antiviral therapy for HEV? What monitoring is needed? For all: what additional tests should be ordered?
Guidance: Mrs A: Tenofovir in third trimester if HBV DNA >200,000 IU/mL reduces vertical transmission; neonatal HBIG + HBV vaccine within 12h is mandatory. Mrs C: No specific antiviral for HEV; supportive care, monitor for fulminant hepatic failure (INR, bilirubin, encephalopathy), obstetric team involvement.
Section 4: Preventive Strategies and Public Health Response (approx. 180 words)
Describe the Universal Immunisation Programme (UIP) schedule for hepatitis B in India (birth dose, 6 weeks, 10 weeks, 14 weeks). What additional protection is given to neonates of HBsAg-positive mothers? What healthcare system changes would prevent HEV outbreaks? Comment on the role of the HEV vaccine (Hecolin) and why it is not yet in the Indian immunisation schedule.
Guidance: Birth-dose HBV vaccine within 24h (ideally within 12h) + HBIG for high-risk neonates. HEV control: safe water supply, improved sanitation, food hygiene. Hecolin (HEV 239) licensed in China; not WHO-prequalified; not in India's UIP. Pregnant women are the highest-priority group for HEV vaccination when available.
Grading Rubric — Hepatitis Serology Interpretation Rubric (25 points)
| Criterion | Points | Full-marks descriptor |
|---|---|---|
| Accuracy of serological interpretation for all three cases | 8 pts | All three diagnoses correct with precise marker justification: Mrs A = chronic active HBV (HBeAg+, high DNA), Mrs B = vaccinated (anti-HBs only, no anti-HBc), Mrs C = HBV window period + acute HEV co-infection; no errors. |
| Vertical transmission risk analysis and infectivity markers | 6 pts | Correctly states 90% neonatal chronicity risk for HBeAg-positive Mrs A; identifies HBV DNA as quantitative infectivity marker; correctly notes 20–25% HEV maternal case fatality and vertical HEV transmission risk in third trimester. |
| Clinical management plan — correctness and completeness | 6 pts | Mrs A: Tenofovir if DNA >200,000 IU/mL mentioned; neonatal HBIG + HBV vaccine within 12h specified. Mrs B: Correctly states no further HBV action needed. Mrs C: Supportive care for HEV, fulminant hepatic failure monitoring specified (INR/bilirubin), obstetric referral mentioned; additional tests ordered appropriately. |
| Preventive strategies and public health reasoning | 3 pts | UIP HBV schedule (birth + 6/10/14 weeks) correctly stated; HBIG for high-risk neonates; HEV prevention linked to safe water + sanitation; HEV vaccine (Hecolin) correctly identified as not yet in India UIP with a reason given. |
| Communication clarity: structured writing, appropriate medical language, within word limit | 2 pts | Well-structured, clear medical prose; all four sections addressed; appropriate use of terminology; within 600–800 word range. |
PEER REVIEW
Review your peer's hepatitis serology report using the rubric criteria as a guide. For each section:
1. Serological accuracy: Did they correctly identify all three diagnoses with marker justification? If Mrs C's dual infection (HBV window + HEV) was missed, note it.
2. Vertical transmission: Was the 90% chronicity risk for HBeAg-positive mothers stated? Was HEV third-trimester risk addressed?
3. Management: Is the neonatal protocol (HBIG + vaccine within 12h) clearly specified? Was HEV management (supportive care + monitoring for fulminant failure) addressed?
4. Prevention: Is the UIP schedule correctly cited?
5. One strength and one specific suggestion for improvement.
Keep feedback specific, constructive, and referenced to the serology data in the scenario. Aim for 150–200 words.