Viral hepatitis is defined as a hepatitis virus infection in which hep
atic inflammation and necrosis lead to a characteristic feature. It is
caused by at least five viral agents with specific epidemiological at
tributes and distinctive immunoserologic findings. The well-characteri
zed forms are hepatitis A, B, C, D and E viruses: Recent status and th
e current progress of viral hepatitis in Japan are discussed in the pr
esent article.