Antiretroviral treatment outcome in HIV-1-infected patients routinely followed up in capital cities and remote areas of Senegal, Mali and Guinea-Conakry.

Introduction: Access to antiretroviral treatment (ART) becomes more and more effective in resource-limited settings (RLS). However, this global effort would be even more profitable if the access to laboratory services especially in decentralized settings was strengthened. We report the virological outcome and HIV-1 drug resistance in three West African countries using dried blood spots (DBS) samples. Methods: We included HIV-1-infected adults on ART >= 6 months and followed up in capital cities and decentralized sites in Senegal, Mali and Guinea-Conakry. Patients were consecutively enrolled and DBS were collected in field conditions and kept at ambient temperature before transfer to the reference laboratory. Viral load (VL) was quantified using the NucliSENS EasyQ HIV-1 v1.2. Genotyping of HIV-1 pol gene was performed using in-house protocol. Results: Of the 407 participants, 119, 152 and 136 were from Senegal, Mali and Guinea-Conakry, respectively. The median treatment duration was 36 months [IQR: 6-136]. Virological failure (VF) (VL >= 3log(10) copies/ mL) was observed in 26% (95% confidence interval (CI), 18-35; n=31), 11% (95% CI, 6-17; n = 16) and 24% (95% CI, 17-32; n = 33) of patients in Senegal, Mali and Guinea-Conakry, respectively (p = 0.001). Of samples presenting VL] 3log(10) copies/ mL (n = 80), 70 were successfully genotyped. At least one drug resistance mutation (DRM) was detected in the following proportions: 70% (95% CI, 50-86; n = 19), 93% (95% CI, 68-100; n = 14) and 68% (95% CI, 48-84; n = 19) in Senegal, Mali and Guinea-Conakry, respectively (p = 0.22). Twenty-six per cent (26%; 95% CI, 16-38; n = 18) of patients in VF harboured wild-type viruses, which is likely indicative of weak adherence. Phylogenetic analysis showed the predominance of CRF02_AG subtype (73%; 95% CI, 61-83; n = 51). Conclusions: We describe the ART outcome in capital and rural settings of Senegal, Mali and Guinea-Conakry. Our results in all of the three countries highlight the need to reinforce the ART adherence in order to minimize the occurrence of drug resistance. In addition, these findings provide additional evidence that the use of DBS as a sampling support could assist virological monitoring of patients on ART in remote areas.