Chronic Hepatitis B

Government estimates are that about 180,000 people in the UK have chronic hepatitis B and the prevalence of hepatitis B surface antigen (HBsAg) among blood donors is around 1 in 1,500. Around one-fifth of HBsAg-positive individuals are HBeAg positive, with 7-20% spontaneously losing HBeAg positivity per year.

There are five therapies for chronic hepatitis B that are currently approved:

• interferon alfa-2b, 
• lamivudine, 
• adefovir, 
• entecavir and 
• pegylated interferon (peginterferon) alfa-2a. 

Given the need for long-term treatment, current guidelines recommend treatment only for patients with elevated aminotransferase levels or histological evidence of moderate or severe inflammation or advanced fibrosis. For patients with HBeAg-positive chronic hepatitis B who do not yet have cirrhosis, the goal is to achieve HBeAg seroconversion, and interferon alfa alone has the best chance of achieving this. Viral suppression without HBeAg clearance is invariably associated with relapse, whereas viral suppression with HBeAg clearance is associated with sustained responses in 50-90% of patients.

Students found to be infected with a blood-borne virus such as hepatitis B are allowed to continue their medical course leading to full medical registration provided they accept the requirement that they will not be allowed to perform exposure-prone procedures while infectious (HBeAg positive or HBeAg negative with >103 genome equivalents/mL HBV DNA), and that careers in some specialties may not be open to them. Registered medical students who are HBeAg negative and who have virus loads that do not exceed 103 genome equivalents/mL will be tested annually in order to confirm that their virus load has not exceeded the threshold at which they would be prohibited from conducting exposure-prone procedures. Those who have undergone a course of treatment need to show that they have a viral load that does not exceed 103 genome equivalents/mL 1 year after cessation of treatment before a return to unrestricted working practices can be considered.