Transmitted HIV-1 Drug-resistance Mutations among Newly Diagnosed Patients of the North Western Region of Cameroon

Background: First line antiretroviral treatment (ART) regimens in Cameroon comprises of reverse transcriptase inhibitors (RTIs). As ART continues to expand, the emergence of HIV drug resistance mutations (DRMs) is a challenging problem. The ongoing scale up of ART in Cameroon has prompted the interest in surveillance of transmitted drug resistance (TDR). The aim of this study was to evaluate the prevalence of TDR among drug naïve individuals residing in the North West Region (NWR) of Cameroon.

Methods: Ethics approval was obtained from the National Ethics Committee of Cameroon and patients informed consents were obtained. A total of 81 HIV-1 infected and drug naïve patients were recruited from randomly selected clinics located in the NWR of Cameroon from February 2016 and April 2016. HIV-1 protease-reverse transcriptase region was sequenced using an in-house protocol. HIV drug resistance mutations were identified and analyzed using Stanford HIVDR database and the Calibrated Population Resistance (CPR) tools. Data was analyzed using SPSS version 23.

Results: Of the 81 samples analyzed, the prevalence of TDR was 11.1% (9/81). Of these 9.9% (8/81) had drug resistance mutations to nucleoside and non-nucleoside reverse transcriptase inhibitors (NRTIs and NNRTIs) and a single individual (1.2%) with protease inhibitors. A total of 8.6 % (7/81), 4.9(4/81), and 3.7 % (3/81) individuals had a major mutation to NRTIs, NNRTIs, and both NRTIs and NNRTIs respectively. Thymidine analogue mutations [TAM] (M41ML, D67N, K70T/R, T215TA/F, and K219Q) were detected in five individuals. The most frequent NRTI and NNRTI DRMs were K219Q (n=2) and E138A (n=2) respectively. Mutations associated with NRTIs were TAM and M184MV; NNRTIs were A98G, K103N, V108I, V179E, and Y181C and I54IFV for PI. CPR tool revealed a 4.9% (4/81) prevalence with the following single mutations K103N D67N, K70R, M184V, T215F, K219Q.The difference between two methods was statistically significant p=0.0001. These mutations confer resistance to all NRTIs and NNRTIs drugs.

Conclusions: Although moderate transmitted drug resistance (11.1%) levels were detected in this study, this calls for routine drug resistance surveillance among patients on ART. This will ensure relative maintenance of low viral suppression amongst HIV patients.