Viral Hepatitis A to E: An Update in 2010

and clinically overt acute hepatitis A is increasing in adolescents and adults. It is well established that the severity of the disease is related to the age of the patients. The clinical features and the epidemiological shift of HAV underscores the importance in Korea, as well as in other countries with similar issues, of childhood vaccination and consideration of catch-up vaccination for adolescents and adults as well as targeted vaccination for individuals at increased risk for infection or its complications. An active campaign for universal childhood HAV vaccination should be continued and catch-up vaccination, which is directed at people between 10 and 50 years of age, should be considered. Additionally, conventional high-risk groups and persons more vulnerable to developing fulminant hepatitis – such as travelers to highly endemic areas, patients medicated with clotting factors and patients with chronic liver disease – should be vaccinated. To provide evidence-based recommendations for HAV vaccination, an urgent nationwide survey of HAV seroepidemiology as well as regional surveys and studies of the cost-effectiveness of vaccination of each vaccination strategy are needed. The clinical spectrum of HAV infection ranges from asymptomatic infection to fulminant hepatitis. Clinical manifestations depend on the age of the host; in other words, less than 30% of infected young children are symptomatic, while about 80% of infected adults manifest as severe hepatitis with remarkably elevated serum aminotransferases. Fulminant hepatitis is rare, with a reported incidence from 0.015 to 0.5%. Atypical manifestaViral hepatitis is still one of the major health-care problems worldwide, since hepatitis B and C can cause the potentially fatal conditions of hepatocellular carcinoma (HCC) and/or liver failure. Similarly, hepatitis A is still a serious problem in Asia and, interestingly, hepatitis E is re-emerging as a topic of medical discussion, since it causes fulminant hepatitis even in developed countries like Japan. The 6th Korea-Japan Liver Symposium was held in Kyongju (Korea) on July 18 and 19, 2009, to focus on and discuss current and emerging topics related to viral hepatitis. The symposium began with eye-opening lectures by some of the world’s leading researchers, followed by extensive discussion. This issue of Intervirology selects the most important articles presented to this congress.