African Study Finds Dolutegravir Resistance: HIV Glasgow 2026

Nearly one in 10 people with sequencing results who met WHO criteria for HIV virological failure had at least low-level resistance to dolutegravir in a routine-care cohort in Lesotho, researchers reported at HIV Glasgow 2026. The findings showed no clear increase in resistance compared with an earlier analysis of the same cohort using data through 2023.

Resistance in Routine HIV Care

Dolutegravir is a cornerstone of antiretroviral treatment across Africa. The study examined how often resistance was detected in people whose HIV viral load remained detectable on repeated testing while taking the drug. The prospective Viral Load Cohort North-East Lesotho, known as VICONEL, follows people receiving viral load monitoring in three districts. It allowed researchers to report how many people qualified for resistance testing and how many had results available.

By June 2026, 27,373 participants had received dolutegravir and had at least 12 months of follow-up. The research team identified 1,007 participants who met the criteria for genotypic testing. The study required at least two viral load results of 50 copies/mL or higher, including at least one result of 500 copies/mL or higher, from samples collected more than 90 days after starting dolutegravir.

Sequencing results were available for 303 eligible participants. Researchers detected at least low-level dolutegravir resistance in 24 of them, giving a prevalence of 7.9% (95% CI: 5.2–11.6%) among those with results. The testing criteria captured people with repeated viraemia at a lower threshold than the WHO definition of virological failure.

Findings Among People With Virological Failure

The investigators separately assessed 142 sequenced participants who met the WHO definition of virological failure, with two consecutive viral loads of at least 1,000 copies/mL. Fourteen had at least low-level dolutegravir resistance, equivalent to 9.9% (95% CI: 5.5–16.1%). This subgroup estimate describes the people with sequencing results whose viral loads met the higher threshold.

Participants with dolutegravir resistance tended to have experienced viraemia on previous regimens, to have reverse transcriptase resistance mutations, and to be receiving a regimen without tenofovir. The descriptive comparisons show which characteristics occurred together in the cohort. The estimates also distinguish detection of any resistance, including low-level resistance, from the clinical definition of virological failure.

Sequencing results were available for 30.1% of participants eligible for testing, leaving uncertainty about how closely the estimates represent the full eligible group. The study’s main contribution is a denominator for interpreting resistance detected in routine care. Reporting the full cohort, the group eligible for testing and the subset with results makes it possible to distinguish the frequency of resistance among tested patients with repeated viraemia from its frequency across all people receiving dolutegravir.

Reference
Klicpera A, Röhl M, Lukau B, et al. Dolutegravir resistance among people with repeated viraemia in a prospective routine HIV care cohort in Lesotho. Abstract O42. Presented at: HIV Glasgow 2026; 8–11 November 2026; Glasgow, UK. J Int AIDS Soc. 2026;29(Suppl 6):e70211. doi:10.1002/jia2.70211