Markers of hepatitis C and B virus infections among blood donors in Ho Chi Minh City and Hanoi, Vietnam.

Blood donors in two cities in Vietnam were tested for markers of hepatitis C virus (HCV) and hepatitis B virus infections. Antibody to HCV was detected by passive hemagglutination with antigens of the second generation in 101 (20.6%) of 491 donors in Ho Chi Minh City; it was detected less frequently (P < 0.001) in donors in hanoi (4 [0.8%] of 499). HCV RNA was tested for in donors with antibody by PCR with nested primers from the 5'-noncoding region and detected in 79 donors in Ho Chi Minh City and 4 donors in Hanoi. HCV RNA was genotyped by PCR with type-specific primers from the core gene. Of 83 HCV carriers from Vietnam, 24 (29%) were infected with HCV of genotype I/1a 19 (23%) were infected with II/1b, 4 (5%) were infected with III/2a, and 2 (2%) were infected with mixed genotypes (I/1a and II/1b); HCV genotypes in the remaining 34 (41%) donors, including all 4 donors in Hanoi, were not classifiable into I/1a, II/2a, IV/2b, or V/3a. Of the 10 isolates with unclassifiable genotypes, 2 showed substantial sequence divergence within the 5'-noncoding region from reported isolates with known genotypes (I/1a to 6a). An analysis of part of the core gene sequence indicated that six of the remaining isolates most likely represented new HCV genotypes. Hepatitis B surface antigen and the corresponding antibody, respectively, were detected in 15 (3.1%) and 234 (47.7%) donors in Ho Chi Minh City as well as 15 (3.0%) and 248 (49.7%) donors in Hanoi. These results indicate an extensive spread of HCV among Ho Chi Minh City donors and HCV of novel genotypes in vietnam.