RESUMO
Hepatitis C virus was shown to be a member of the flavivirus family. Tick-borne encephalitis virus and West Nile virus, members of the same family occur in Hungary, too. Serum samples from patients suffering from transfusion associated hepatitis were tested with yellow fever virus antigens for specific IgG, and IgM using immunofluorescence test. Eight hundred serum samples were tested. Yellow fever virus related IgG antibodies were found in 232 sera. In the case of 72 patients specific IgM antibodies could also be detected. The majority of the IgM positive patients underwent surgical operation and/or blood transfusion 1 to 2 months before the onset of the disease. Fifty-four sera positive for yellow fever virus-related antibodies were tested with HCV reagents, but only 13 were found to be positive, or cross-reacting. The 20 patients with yellow fever related antibodies were controlled with tick-borne encephalitis antigens, too. Nevertheless, no measurable cross-reaction could be detected. No measurable cross-reaction could be detected with the West Nile virus. The hepatitis B markers also were tested in 44 sera positive for yellow fever antibodies. There was only one, which contained HBsAg, and 10 of them proved to be positive for anti-HBcAg. The results indicate, that a non-A, non-B, non-C flavivirus is also present in the Hungarian population, which can be detected on the basis of the antigenic cross-reactivity with the attenuated yellow fever virus. This virus seems to be responsible for every 11th transfusion associated hepatitis examined.(ABSTRACT TRUNCATED AT 250 WORDS)