Management of non A, non B hepatitis: the problem and its treatment.

Non A, non B (NANB) hepatitis is caused by at least three, as yet unidentified, viruses and can occur as a result of blood transfusions, the use of blood products, covert or overt percutaneous exposure and epidemic waterborne outbreaks of infection. The three types of viruses are characterised by their incubation times; a short time of 2-4 weeks, a longer time of 6-12 weeks and a intermediate period for the waterborne NANB hepatitis virus. Acute NANB hepatitis is milder than HBV hepatitis with lower peak transaminase levels. However, some develop into fulminant hepatitis with a lower survival rate of 0.13%. Ten to 100% of acute patients progress to chronic NANB hepatitis. It was found that alpha-lymphoblastoid interferon at levels of 3-5 megaunits (MU) thrice weekly returned transaminase levels to normal within 6-8 weeks. Approximately 80% had normal levels by the eighth week of treatment and this was maintained on 2.5-3 MU thrice weekly; a well tolerated dose. Long term, low-dose therapy is needed to maintain remission.