Which of the following is a clinical feature of hepatitis B but not hepatitis A?

Chronic infection is a significant clinical feature of hepatitis B that distinguishes it from hepatitis A. Hepatitis B can lead to a persistent infection that lasts for more than six months and can result in chronic liver disease, which may include cirrhosis, liver failure, or even liver cancer. This chronic phase can occur because the immune response is unable to fully clear the virus from the body.

In contrast, hepatitis A is typically an acute infection that resolves on its own within a few weeks to months. Individuals infected with hepatitis A usually recover completely without developing chronic liver disease. Therefore, the potential for chronic infection is a clear differentiator between hepatitis B and hepatitis A, making it the most appropriate choice in this scenario.

While the other features—fulminant hepatitis, jaundice, and dark urine—can occur in both hepatitis A and B, chronic infection is unique to hepatitis B and plays a crucial role in the long-term health outcomes associated with the disease.