We performed viral load (VL) and antiretroviral (ARV) drug resistance genotyping assays using dried blood spot samples (DBS) taken from HIV-1 infected patients in Chad. Among 80 adult patients naïve of any antiretroviral treatment regimen, 67 (84%) had a measured VL upper than 40 copies/ml (median; SD: 36891 copies/ml; [603-2 798 968]) of blood. Of them only 24 (36%) demonstrating a viral load upper was than 3.63 log₁₀ copies/ml were successfully sequenced for performing a drug resistance genotyping assay. Of the 24 patients whom DBS samples were successfully sequenced, seven (29%) displayed the presence of an HIV-1 strain with known mutations conferring resistance against at least one ARV family. Our pilot study provides major data on the high prevalence levels of primary resistance to available ARV drugs in HIV-1 infected patients in Chad and highlights the need for a wide and rational use of HIV anti-integrase drugs in Sahelian area.

DBS, HIV viral load, Chad, NNRTI- or NRTI- primary resistant HIV strains