Prevalence of Antiretroviral Drug Resistance in Treated HIV-1 Infected Patients: Under the Initiative of Access to the NNRTI-Based Regimen in Thailand

Abstract

To determine the prevalence of antiretroviral resistance in treatment-failure HIV-1 infected individuals, under the initiative of the non-nucleoside reverse transcriptase inhibitor (NNRTI)-based regimen in Thailand, plasma samples were collected from 1,376 HIV-1 infected patients, who were failing in their current HAART therapy during 2000-2004. They were stratified into 2 intervals: group one (1), 558 HIV-1 infected patients (2000-2002; before the initiative of access to HAART), and group two (2), 818 HIV-1 infected patients (2003-2004; after the initiative of access to HAART). Genotypic resistance testing was performed. The frequency of antiretroviral drug resistance in treatment-failure HIV-1 infected patients has significantly increased over time from 68.5% (382/558) during 2000-2002 to 74.9% (613/818) during 2003-2004 (P<0.01). Resistance to NNRTI during 2003-2004 (59.2%) was much higher than that during 2000-2002 (36.9%; P<0.001). However, the frequency of nucleoside reverse transcriptase inhibitor (NRTI) drug resistance was not significantly higher (P=0.153). We showed that this correlated with an increase in the NNRTI-based regimen prescribed during 2003-2004, especially the Thai-produced combination pill, GPO-VIR. Our finding also showed that a high level of genotypic drug resistance is associated with GPO-VIR (40.8% lamivudine, 40.6% stavudine, 43.8% nevirapine). In order to avoid the rapid emergence of resistant viruses in a resource-poor setting, a close surveillance of antiretroviral drug resistance is feasible and should be considered.