RESUMO
Introduction.The NAMSAL therapeutic trial evaluated the non-inferiority of a first line treatment comprising Dolutegravir to another line comprising Efavirenz 400. The criteria for not taking part to the trial included infection with non-M HIV-1, untreated patients with HIV viral load <1000 copies/mL. The objective of this study was to explain why some treatment naïve patients had undetectable viral loads. Materials and methods. Out of 817 patients pre-included with HIV-1 infection and untreated, 204 were not included and the present study focused on 114 of these 204 patients not included in NAMSAL. HIV plasma viral load, serological status and the serotype were confirmed by RT-qPCR (Abbott), INNOLIA HIVI/II Score (Fujirebio), and by ELISA with synthetic peptides of thedifferent HIV-1&2 groups. Universal or specific PCR (M and O) were performed on the samples for molecular confirmation and characterization. Results. Amongthe 114 patients studied, 49 (43%) had a viral load < 1000 copies/mL and 65 (57%) had a viral load > 1000 copies/mL. When reported to the whole cohort of pre-included patients (n=817), 4/817 (0.5%) were group-O confirmed by molecular biology. Based on the PCR results, 14 out of 817 patients (1.7%) deemed to be HIV-1 positive were most likely uninfected. Conclusion. 1.7% of HIV-1 patients referred for inclusion in NAMSAL were not actually infected. Ongoing staff training and quality control of laboratories must be strengthened in Cameroon in view of the social and economic consequences of misdiagnosis.