Hepatitis A, B, C and E in children — formative SAQs

SAQ 1 (10 marks)

A term infant is delivered vaginally to a mother known to be hepatitis B surface-antigen positive and hepatitis B e-antigen positive with a high HBV DNA. The midwife asks you what must be done for the baby. [4]

Question: Outline the prevention pathway for this neonate, including the rationale, the specific interventions, the timing, and the follow-up testing. (10 marks) [6]

Model answer

Rationale and transmission risk (2 marks). A mother who is HBsAg and HBeAg positive with high HBV DNA has the highest vertical-transmission risk; without immunoprophylaxis, the majority of such neonates become chronic carriers because the immature immune system enters an immune-tolerant phase that lets the virus persist. Chronic carriage carries a lifetime risk of cirrhosis and hepatocellular carcinoma, so preventing the infection at birth is the single most impactful intervention in the whole topic. [4] [6]

The birth-dose bundle — vaccine and immunoglobulin (3 marks). The baby must receive the hepatitis B vaccine AND hepatitis B immunoglobulin (HBIG) within 24 hours of birth, ideally within 12 hours, given at separate intramuscular injection sites. This is the non-negotiable, never-miss bundle: the vaccine induces active immunity while the HBIG provides immediate passive antibody cover during the window before the vaccine response develops. The hepatitis B vaccine series is then completed through infancy on the standard schedule. [4] [6]

Maternal suppression and the delivery context (2 marks). For a high-viraemic mother, maternal tenofovir in the third trimester further suppresses HBV DNA and reduces the residual transmission that immunoprophylaxis alone does not prevent; in this case the antenatal window has passed, but the principle frames why antenatal HBV DNA testing and maternal suppression are offered. Mode of delivery is not altered for hepatitis B alone, and breastfeeding is not contraindicated once the baby has received immunoprophylaxis. [4] [6]

Follow-up testing and surveillance (2 marks). At 9 to 12 months of age, test the infant for HBsAg and anti-HBs: a negative HBsAg with positive anti-HBs confirms protection; a positive HBsAg indicates chronic carriage and triggers lifelong surveillance. The infected infant is referred to paediatric hepatology for ALT and HBV DNA monitoring, fibrosis assessment and hepatocellular-carcinoma surveillance, with vaccination of susceptible household contacts. [6]

Safety-net and family (1 mark). The family is counselled, household and sexual contacts are screened and vaccinated, and the child's records flag the chronic hepatitis B status for transition to adult care. The lesson is that this bundle, delivered within twenty-four hours, is what prevents a lifetime of chronic liver disease. [4] [6]

SAQ 2 (10 marks)

Question: A 15-year-old asylum-seeker is found on refugee screening to be anti-HCV positive and HCV RNA positive (genotype 1) with normal ALT and no fibrosis on elastography. (a) Outline the diagnosis and its limitations. (b) Outline the management and counselling. (c) What is the prognosis, and what surveillance is needed? (10 marks) [10]

Model answer

(a) Diagnosis and limitations (3 marks). The diagnosis of chronic hepatitis C is confirmed by a detectable HCV RNA — the antibody alone cannot distinguish past from active infection, so the RNA is the confirmatory test. In an adolescent the antibody is reliable (unlike in an infant under ~18 months, where maternal antibody confounds serology), so this is true chronic infection. The normal ALT and absent fibrosis place her in early chronic disease. A paracetamol, drug, autoimmune and metabolic contribution is excluded by history and a basic liver screen, and co-infection with hepatitis B and HIV is sought. [10] [8]

(b) Management and counselling (4 marks). The management is test-and-treat: confirm active infection with HCV RNA (done), and treat with an age-appropriate pangenotypic direct-acting antiviral regimen, with which sustained virological response (cure) rates exceed ninety-five percent in children and adolescents. There is no hepatitis C vaccine or immunoglobulin, and deferral to adulthood is no longer necessary. She is vaccinated against hepatitis A and B to prevent co-infection. Counselling covers transmission — blood and sexual, not casual — not sharing razors or toothbrushes, not donating blood, and alcohol avoidance; and the reassurance that hepatitis C is not spread by casual household contact and that breastfeeding is not contraindicated for a future pregnancy after cure. [9] [10]

(c) Prognosis and surveillance (3 marks). The prognosis is excellent: chronic hepatitis C is now curable in the great majority of children with short, well-tolerated oral courses. Even after cure, surveillance for fibrosis and hepatocellular carcinoma continues where disease was established, and the young person is transitioned to adult hepatology care. The broader prevention is test-and-treat of women of childbearing age, which reduces vertical transmission (roughly five to six percent of infants of HCV-RNA-positive mothers are infected). The lesson is that the paediatrician confirms with HCV RNA and refers for cure, rather than deferring. [9] [8]