BACKGROUND: HIV drug resistance can reduce the effectiveness of antiretroviral drugs in preventing morbidity and mortality, limit options for treatment, and prevention. Our study aimed to assess HIV-1 subtypes and HIV drug resistance among key populations in HIV Sentinel Surveillance Plus Behavior in 2018 and 2020. METHODS: One-stage venue-based cluster sampling was used to recruit participants at hotspots identified for men who have sex with men (MSM) in 7 provinces and sexual minority females and female sex workers (FSW) in 13 provinces. Participants completed a standard questionnaire about risk and preventive behaviors, and antiretroviral therapy history, and provided intravenous blood for HIV testing. HIV drug resistance testing was conducted on HIV-positive samples with viral load >1000 copies/mL. RESULTS: A total of 185 of 435 (42.5%) HIV-positive samples had viral load ≥1000 copies/mL, of which 130 of 136 from MSM and 26 of 49 from FSW were successfully sequenced. Six HIV-1 subtypes were detected (CRF01_AE, A, CRF07/08_BC, B, C, CRF25_cpx), with CRF01_AE (82.7%, 129/156) the most common. Drug resistance mutations were detected in 16.7% of participants overall (26/156), in 15.4% (20/130) of MSM, and in 23.1% (6/26) of FSW. Mutations associated with resistance to non-nucleoside reverse transcriptase inhibitor (NNRTI) were the most frequently detected (73.1%, 19/26). The high level of resistance was presented in NNRTI and nucleoside reverse transcriptase inhibitors classes. There are 10 major resistance mutations detected with nucleoside reverse transcriptase inhibitors (M184VI-25.0%, K65KR-50.0%, Y115F-25%), NNRTI (K103N-21.1%, E138A-10.5%, V106M-5.3%, K101E-5.3%, G190A-5.3%), protease inhibitors (L33F-40.0%, M46L-20.0%). CONCLUSIONS: Vietnam's HIV Sentinel Surveillance Plus system identified an emerging strain of HIV-1 and mutations associated with resistance to multiple drug classes among MSM and FSW.

OBJECTIVE: Women who sell sex and use drugs have dual risks for HIV infection. Despite increasing reports of drug use among female sex workers (FSW) in Vietnam, FSW HIV interventions remain focused mainly on sexual risk reduction. We assessed the impact of drug use and inconsistent condom use on HIV infection among FSW in Vietnam, which few studies have quantified. METHODS: We surveyed 5298 women aged ≥18 years who had sold sex in the past month from ten geographically dispersed provinces. We performed multivariate logistic regression on data from provinces with high (≥10%) or low (<10%) HIV prevalence among FSW. RESULTS: Compared to FSW who never used illicit drugs, the odds of HIV infection among FSW who had ever injected drugs and those who reported non-injection drug use were 3.44 (CI 2.32-5.09) and 1.76 (CI 1.14-2.71), respectively, in high-prevalence provinces. FSW who always used condoms with clients had lower odds of HIV infection than those who did not (AOR=0.71; CI 0.52-0.98). In low-prevalence provinces lifetime injection drug use (AOR 22.05, CI 12.00-40.49), but not non-injecting drug use or inconsistent condom use, was significantly associated with HIV infection. CONCLUSIONS: Because injection drug use and inconsistent condom use were key risk factors for HIV infection in high-prevalence provinces, drug injection risk reduction should be as much a focus of HIV prevention as sexual risk reduction. Where HIV prevalence remains low in FSW, a more general emphasis on harm reduction for all drug users will benefit FSW.