Effect of pretreatment HIV drug resistance on mortality, attrition and viral suppression in patients initiating antiretroviral therapy and genetic transmission network: an observational cohort study in Southwest China.

OBJECTIVES

Pretreatment drug resistance (PDR) compromises antiretroviral therapy (ART) efficacy and is a major concern in HIV care, yet its consequences for key treatment outcomes are not well-defined. We therefore systematically investigated the prevalence of PDR and its impact on mortality, attrition and viral suppression amongst patients starting ART.

METHODS

An observational cohort study was conducted in Southwest China, 2014-2022. PDR was analysed using the Stanford HIV Drug Resistance Database. Molecular transmission networks were constructed with HIV-TRACE. Cox and logistic regression evaluated the impact of PDR.

RESULTS

Amongst 3478 eligible patients, the overall prevalence of PDR was 6.4%. PDR rates to non-nucleoside reverse transcriptase inhibitors (NNRTIs), nucleoside reverse transcriptase inhibitors and protease inhibitors were 4.1%, 1.3% and 1.1%, respectively. The overall mortality and attrition rates were 4.58 and 2.40 per 100 person-years, respectively. Whilst PDR showed no significant association with mortality, it was associated with increased attrition. Compared to those without resistance, the adjusted HR (95% CI) for attrition was 1.67 (1.11-2.52) in the overall drug-resistant group, 2.16 (1.36-3.43) in the NNRTI-resistant group and 2.09 (1.10-3.97) in the efavirenz/nevirapine-resistant group. Viral suppression was significantly lower in the drug-resistant group [adjusted odds ratio (AOR): 0.46; 95% CI: 0.27-0.77], the NNRTI-resistant group (AOR: 0.42; 95% CI: 0.22-0.78) and the efavirenz/nevirapine-resistant group (AOR: 0.41; 95% CI: 0.21-0.81).

CONCLUSIONS

Our study reveals a moderate prevalence of PDR in Southwest China, significantly associated with increased risk of attrition and virologic failure, particularly amongst patients with resistance to efavirenz/nevirapine. Our findings strongly advocate for routine PDR testing prior to ART initiation to guide optimal first-line treatment strategies.