GEOGRAPHICAL-DISTRIBUTION OF HEPATITIS-C VIRUS GENOTYPES IN BLOOD-DONORS - AN INTERNATIONAL COLLABORATIVE SURVEY

The frequency of infection with the six classified major genotypes of hepatitis C virus (HCV) was investigated in 447 infected volunteer blo od donors from the following nine countries: Scotland, Finland, The Ne therlands, Hungary, Australia, Egypt, Japan, Hong Kong, and Taiwan. Vi ral sequences in plasma from blood donors infected with HCV were ampli fied in the 5'-noncoding region and were typed by restriction fragment length polymorphism analysis. Electrophoresis of DNA fragments produc ed by cleavage with HaeIII-RsaI and ScrFI-HinfI allowed HCV types 1 (o r 5), 2, 3, 4, and 6 to be identified. Further analysis with Mval-Hinf I allowed sequences of the type 5 genotype to be distinguished from se quences of the type I genotype. Types 1, 2, and 3 accounted for almost all infections in donors from Scotland, Finland, The Netherlands, and Australia. Types 2 and 3 were not found in the eastern European count ry (Hungary), where all but one of the donors were infected with type 1. Donors from Japan and Taiwan were infected only with type 1 or 2, w hile types 1, 2, and 6 were found in those from Hong Kong. HCV infecti on among Egyptians was almost always by type 4. Donors infected with H CV type 1 showed broad serological reactivity with all four antigens o f the second generation Chiron RIBA-2 assay (Chiron Corporation, Emery ville, Calif.), while infection with divergent HCV genotypes elicited antibodies mainly reactive to c22-3 and c33c. Reactivities with antibo dies 5-1-1 and c100-3 were infrequent and were generally weak, irrespe ctive of the geographical origin of the donor. Because the envelope re gion of HCV is even more variable than the NS-4 region, it is likely t hat vaccines based on these proteins need to be multivalent and perhap s specifically adapted for different geographical regions.