Molecular epidemiology and trends of HIV-1 subtypes in Taiwan.

To understand the trends of distribution and risk factors associated with different HIV-1 subtypes in different populations in Taiwan, blood samples and questionnaires were collected from 267 male and 21 female HIV-1-infected people in a multicenter survey from 1993 to 1996. This group represented about one quarter of the total registered HIV-1 cases in Taiwan. The HIV-1 subtypes were determined using V3-based peptide-enzyme immunoassays complemented by heteroduplex mobility assay and phylogenetic tree analysis. The results showed that in Taiwan, men were primarily infected with HIV-1B (68.2%) and HIV-1E (27.3%), whereas women were mainly infected with non-B subtypes (4.8% A, 4.8% C, 71.4% E, and 9.5% G). In addition, 71.4% of men with HIV-1B were homosexual or bisexual, whereas 56.2% of men with HIV-1E were heterosexual (p < .001). Although HIV-1E subtype came to Taiwan later than HIV-1B, it has become a major subtype in the heterosexual population.