Molecular epidemiology of HIV‐1 subtypes and drug resistant strains in Taiwan

Abstract

The Taiwanese government has provided free highly active antiretroviral therapy since April 1997. Previously, we have reported on the molecular epidemiology of HIV-1 in Taiwan from 1988 to 1998. In addition, an outbreak of circulating recombinant form (CRF) 07_BC among intravenous drug users was noted in 2004. Therefore, the purposes of this study were to elucidate the distribution of HIV-1 subtypes among different high-risk groups in Taiwan from 1999 to 2000 and to conduct surveillance on drug resistance among treatment naïve patients from 1997 to 2000. Blood samples from 239 HIV-1/AIDS patients and their subtypes were examined using DNA sequencing and phylogenetic analysis. The results showed that among 226 male patients, 213 (94.2%) had subtype B, 11 (4.9%) had CRF01_AE, 1 had unique recombinant strain related to both CRF07_BC and CRF08_BC (strain T12-99TW) and 1 had CRF08_BC (strain L9312-00TW). The patients infected with T12-99TW and L9312-00TW were intravenous drug users and had needle-sharing experiences in Yunnan Province, China. Of the 13 HIV-1-infected females, 7 (53.8%) had subtype B, 5 (38.5%) had CRF01_AE, and 1 (7.7%) had subtype C. Phylogenetic analysis demonstrated that the neither strain T12-99TW nor L9312-00TW clustered with CRF07_BC strains isolated from Taiwanese intravenous drug users in 2004. In addition, 126 treatment naïve patients were selected for genotypic DR analysis and the results showed that 4.3% (2/47) homosexual males had M184V mutations. This is the first report on the identification of CRF08_BC and a unique recombinant strain related to both CRF07_BC and CRF08_BC in Taiwan.