Infants who contract Hepatitis B at birth are at high risk for chronic infection. Which option reflects this scenario?

• A. A 55-year-old male with Hepatitis A
• B. An infant who contracted Hepatitis B at birth
• C. A 32-year-old female with Hepatitis C who reports IV drug use
• D. A 50-year-old male with alcoholism and Hepatitis D

Answer: (B)

The key idea is that hepatitis B acquired at birth is much more likely to become a long‑term (chronic) infection. When HBV is transmitted perinatally from an infected mother to a newborn, the infant’s immature immune system often does not mount a robust clear‑the‑virus response, so the virus persists. In fact, about 90% of infants infected at birth develop chronic HBV, compared with only a small fraction of adults who become infected. This is why the infant who contracted Hepatitis B at birth best reflects a scenario with high chronic infection risk.

Vaccination at birth, along with hepatitis B immune globulin for infants born to HBV‑positive mothers, can greatly reduce the chance that the newborn will become chronically infected by helping the immune system mount a protective response early. In contrast, Hepatitis A typically does not cause chronic infection, Hepatitis C infection in an adult often becomes chronic but does not illustrate perinatal HBV risk, and Hepatitis D requires HBV and is not the perinatal HBV scenario.