Abstract Body


Malawi switched from protease inhibitor- (PI) and non-nucleoside reverse transcriptase inhibitor (NNRTI)-based paediatric first- and second-line antiretroviral therapy (ART) regimens to dolutegravir-based regimens (DBR) in 2020. By 2022, over 98% of children living with HIV (CLHIV) were on DBR, requiring monitoring of dolutegravir (DTG) resistance. We evaluated the prevalence and patterns of drug resistance (DR) to DBR in children in Malawi.


We conducted a cross-sectional survey in 19 clinics randomly selected from the 25 highest volume ART clinics in Malawi from November 2022 to March 2023. We included CLHIV aged <15 years, on a DBR ≥9 months, returning to the clinic after a previous high viral load (VL) ≥1000 cps/ml and having completed at least 1 session of intensive adherence counselling (IAC) per national guidelines. A plasma sample was obtained for VL re-testing. Samples with VL ≥1000cps/ml were genotyped for DR using HIV-1 Genotyping kit with Integrase (ThermoFisher) and interpreted using Stanford University HIVDR Database Algorithm (version 9.4). We present weighted estimates of DR (level 3-5) with 95% confidence limits accounting for correlation within clinic using SAS.


Of the 297 CLHIV re-tested for VL, 43.1% (128/297) remained unsuppressed. Out of the 128 CLHIV that remained unsuppressed, 97.7% (125/128) were successfully genotyped for DR mutations (DRMs). For those successfully genotyped, median age was 10 years old (IQR 5-13); 58% were male, median time since ART initiation was 5.4 years (IQR 2.5-9.0); median time on DTG was 1.5 years (IQR 1.2-2.3); and 89% were ART-experienced at DTG initiation. The weighted prevalence of high-level DTG resistance among children with virological failure was 15.5% (95% CI: 6.7-24.3). The most common major DTG DRMs were R263K (10), E138K/A (5), S147G (4), and G118R (4). Resistance to any nucleoside reverse transcriptase was 41.1%, (95%CI: 27.6-54.6); to any NNRTI was 65.0%, (95%CI: 53.8-76.2); and any PI was 5.2% (95%:CI: 0.0-12.2).


Among Malawian CLHIV with confirmed virological failure on DBR, DTG DRM prevalence was 15.5%, twice as high as the 8.5% found in a parallel study among Malawian adults. Prevalence of DRM to PI was rare. These collective results raise concern about effective future treatment of CLHIV, as there are no convenient alternative 2nd or 3rd line ART options currently available for this population.