Virological Suppression and Patterns of Resistance Amongst Patients on Antiretroviral Therapy at 4 Nigerian Military Hospitals.

Background: In resource-constrained settings, plasma HIV-1 RNA quantification has not been routinely available for the monitoring of response to antiretroviral therapy. This study evaluated virological suppression rates amongst patients on first-line ART in four Nigerian military hospitals.

Methods: We conducted a cross-sectional study of 325 randomly selected adult clinic clients (≥18 years old) on first-line ART regimens at four Nigerian military hospitals. Plasma HIV-1 RNA was assayed using a Roche COBAS TaqMan48 with High Pure System. Virological failure was defined as HIV-1 RNA >1000 copies/ml. Specimens with HIV-1 RNA >1000 copies/ml were referred for genotyping.

Results: HIV-1 RNA results were obtained in 322 participants. Two hundred and seventy-eight study participants (86.3%) had HIV viral RNA < 1000 copies/ml, including 273 (84.8%) with HIV- 1 RNA <400 copies/ml. HIV drug resistance genotyping results were obtained in 35 of 44 study participants with HIV-1 RNA >1000 copies/ml. Only 14% (5/35) had no resistance mutations. Of the remainder, 10% (3/30) had no nucleoside analogue mutations while 33% (10/30) had only M184V along with non-nucleoside reverse transcriptase inhibitor (NNRTI) mutations (K103N or Y188C). 25% (5/25) of participants failing on Zidovudine had more than two thymidine analogue mutations (TAMs).

Conclusion: We observed a high virological suppression rate among the study participants. However, a large proportion of virologically unsuppressed clients had identifiable resistance mutations. The study demonstrates that viral load monitoring is feasible at Nigerian military hospitals and supports the current WHO HIV treatment guidelines which emphasize virological monitoring of patients on ART for early detection of treatment failure.