High level of HIV-1 drug resistance among patients with HIV-1 and HIV-1/2 dual infections in Guinea-Bissau

Sanne Jespersen, Martin Tolstrup, Bo Langhoff Hønge, Candida Medina, David da Silva Té, Svend Ellermann-Eriksen, Lars Østergaard, Christian Wejse, Alex Lund Laursen, for The Bissau HIV cohort study group

With the widespread use of antiretroviral treatment (ART) in Africa, the risk of drug resistance has increased. The aim of this study was to evaluate levels of HIV-1 resistance among patients with HIV-1 and HIV-1/2 dual infections, treated with ART, at a large HIV clinic in Guinea-Bissau. Patients were selected from the Bissau HIV cohort. All patients had HIV-1 or HIV-1/2 dual infection, a CD4 cell count performed before and 3-12 months after starting ART, and a corresponding available plasma sample. We measured viral load in patients with HIV-1 (n = 63) and HIV-1/2 dual (n = 16) infections a median of 184 days after starting ART (IQR: 126-235 days). In patients with virological failure (defined as viral load >1000 copies/ml) and with sufficient plasma available, we performed an HIV-1 genotypic resistance test. Thirty-six patients (46%) had virological failure. The CD4 cell count did not predict treatment failure. Of the 36 patients with virological failure, we performed a resistance test in 15 patients (42%), and nine patients (9/15; 60%) had resistance mutations. The most common mutation was K103N, which confers high-level resistance to non-nucleoside reverse transcriptase inhibitors (NNRTI). No major mutations against protease inhibitors (PI) were found. Our results showed that patients with HIV-1 and HIV-1/2 dual infections in Guinea-Bissau had a high rate of virological failure and rapid development of NNRTI resistance. It remains to be determined whether a more robust, PI-based treatment regimen might benefit this population more than NNRTIs.