Retrospective study of the prevalence of acquired drug resistance after failed antiretroviral therapy in Libya.

Background: The increasing rate of drug-resistant HIV mutations in Libya and other African countries threatens the efficacy of antiretroviral therapy (ART), thus necessitating urgent regional strategies to combat resistance and improve treatment outcomes.

Aim: To characterize the frequency and pattern of acquired HIV drug resistance mutations in patients showing ART failure while using non-nucleoside reverse transcriptase inhibitors (NNRTI) prescribed by the Department of Infectious Diseases at Tripoli University Hospital, Libya.

Methods: We collated retrospective data on 128 people living with HIV, aged 18 years or above, who experienced firstline treatment failure at Tripoli University Hospital, Libya, from 2014 to 2017. We analysed the extant HIV amino acid sequences to identify resistance mutations using algorithms from the Stanford University HIV drug resistance database.

Findings: All included cases had at least one resistance mutation (n = 128; 100%) and 119 (93%) had both nucleoside reverse transcriptase inhibitors (NRTI) and NNRTI mutations. M184V/I was the most common NRTI mutation (n = 119; 93%) while K103N was the most common NNRTI mutation (n = 100; 78%). Thymidine analog mutations were detected in 51 cases (40%); featuring T215Y, D67N and M41L. Predicted full susceptibility was highest for Tenofovir (66.4%), followed by Etravirine (60%).

Conclusion: We detected high level drug resistance and associated mutations among people living with HIV. Implementing drug regimens with high genetic barriers to resistance, coupled with rigorous monitoring and surveillance of HIV resistance development, could help mitigate such resistance in the future.