High level of HIV drug resistance informs dolutegravir roll-out and optimized NRTI backbone strategy in Mozambique
Valentina Carnimeo, Ivan Alejandro Pulido Tarquino, Sonsoles Fuentes, Deise Vaz, Lucas Molfino, Natalia Tamayo Antabak, Rosa Marlene Cuco, Aleny Couto, Sheila Fagundes Lobo, J de Amaral Fidelis, J S Mulassua, Iza Ciglenečki, Tom Ellman, Birgit Schramm
Abstract
BACKGROUND: HIV drug resistance (HIV-DR) is rising in sub-Saharan Africa in both ART-naive and ART-experienced patients. OBJECTIVES: To estimate the level of acquired DR (ADR) and pre-treatment DR (PDR) across selected urban and rural sites in Southern Africa, in Mozambique. METHODS: We conducted two cross-sectional surveys among adult HIV patients (October 2017-18) assessing ADR and PDR. In the (ADR) survey, those on NNRTI-based first-line ART for ≥6 months were recruited (three sites). In the PDR survey, those ART-naive or experienced with ≥3 months of treatment interruption prior were enrolled (eight sites). RESULTS: Among 1113 ADR survey participants 83% were receiving tenofovir (TDF)/lamivudine (3TC)/efavirenz (EFV). The median time on ART was 4.5 years (Maputo) and 3.2 years (Tete), 8.3% (95% CI 6.2%-10.6%, Maputo) and 15.5% (Tete) had a VL ≥ 1000 copies/mL, among whom 66% and 76.4% had NNRTI+NRTI resistance, and 52.8% and 66.7% had 3TC+TDF-DR. Among those on TDF regimens, 31.1% (Maputo) and 42.2% (Tete) were still TDF susceptible, whereas 24.4% and 11.5% had TDF+zidovudine (ZDV)-DR. Among those on ZDV regimens, 25% and 54.5% had TDF+ZDV-DR. The PDR survey included 735 participants: NNRTI-PDR was 16.8% (12.0-22.6) (Maputo) and 31.2% (26.2-36.6) (Tete), with a higher proportion (≥50%) among those previously on ART affected by PDR. CONCLUSIONS: In Mozambique, viral failure was driven by NNRTI and NRTI resistance, with NRTI DR affecting backbone options. NNRTI-PDR levels surpassed the WHO 10% 'alert' threshold. Replacing NNRTI first-line drugs is urgent, as is frequent viral load monitoring and resistance surveillance. Changing NRTI backbones when switching to second-line regimens may need reconsideration.