Work

Understanding integrase inhibitor resistance in Angola: a comparative analysis of INSTI-naive and INSTI-experienced individuals

Year: 2026

Type: article

Abstract: BACKGROUND: Africa remains a major epicentre of the global HIV epidemic, with Central Africa exhibiting extensive HIV-1 genetic diversity that may influence the emergence and transmission of drug resistance mutations. Following World Health Organization recommendations, Angola initiated the national transition to dolutegravir (DTG)-based antiretroviral therapy (ART) in 2021. This study evaluated the frequency, patterns and temporal trends of HIV-1 drug resistance mutations before and after DTG implementation (2019-23), while also characterizing HIV-1 genetic diversity across Angolan provinces outside Luanda. METHODS: A retrospective observational analytical study comparing pre- and post-Integrase strand transfer inhibitor (INSTI) introduction periods was conducted using plasma samples and dried blood spot cards from 17 provinces of Angola. RESULTS: Of the 201 samples analysed, 102 were successfully sequenced for at least one coding region [protease (n = 65); reverse transcriptase (n = 66); integrase (IN) (n = 86)], comprising 48 INSTI-naive people living with HIV and 54 INSTI-experienced people living with HIV samples. Subtype C was the most prevalent (21.6%), followed by unique recombinant forms (20.6%), A1 (15.7%), F1 (13.7%), CRF02_AG (10.8%), G (8.8%) and other subtypes or recombinants (8.8%). Resistance to non-nucleoside reverse transcriptase inhibitors was the most common (68.2%; 95% CI 56.2-78.2), followed by nucleoside reverse transcriptase inhibitors (48.5%; 95% CI 36.8-60.3). Resistance to protease inhibitors (PIs) and INSTIs was lower, observed in 1.5% (95% CI 0.3-8.2) and 3.5% (95% CI 1.2-9.8), respectively. CONCLUSIONS: In this analysis, substantial HIV-1 genetic and epidemiological complexity was observed. In the context of the rapid scale-up of DTG-based ART, continued surveillance of INSTI resistance mutations has become increasingly important to inform evidence-based public health strategies aimed at preventing the transmission of drug-resistant HIV strains and optimizing ART regimens at the population level.

Source: Journal of Antimicrobial Chemotherapy

DOI: 10.1093/jac/dkag355