Hepatitis A, B, and C cause acute infection of the liver that may manifest as an acute icteric illness or be detected incidentally as raised transaminase levels.1 Most cases are diagnosed only in retrospect on serological screening. Hepatitis B and C can persist as chronic infections (>6 months). ### Hepatitis A Hepatitis A virus (HAV) is transmitted faeco-orally.2,3 There is evidence for sexual transmission between homosexual men with several outbreaks reported. The specific risk factors are not well defined but probably relate to oro-anal or digital-rectal contact,1,4,5 particularly in settings such as public saunas and dark rooms. Acute icteric hepatitis appears after an incubation period of 15–45 days, symptoms last for about 6 weeks, and it is only rarely fatal. Most infections are asymptomatic (but severity increases with age). Infectivity lasts from approximately 2 weeks before the onset of jaundice to 1 week after.6 Diagnostic tests for HAV are recommended in anyone presenting with an acute illness or raised transaminase levels, suggesting acute hepatitis, and in contacts of known cases (sexual, household, or other close contact) (evidence level II). Screening of asymptomatic sexually transmitted diseases (STD) clinic attendees is recommended to ascertain their immune status only if they meet the criteria for hepatitis A vaccination (see National Guideline on Management of the Viral Hepatitides A, B and C), which includes homosexual men in regions where an outbreak of hepatitis A has been reported, injecting drug users, and patients with chronic hepatitis B or C or other causes of chronic liver disease (evidence level III).1,6 ### Hepatitis B Hepatitis B virus (HBV) infection is transmitted vertically (mother to child), parenterally, and sexually.7,8,9,10,11,12,13,14 There is a much lower risk to household contacts of acute cases and high infectivity carriers. Of individuals …