Declining trends in early warning indicators for HIV drug resistance in Cameroon from 2008-2010: lessons and challenges for low-resource settings.

BACKGROUND: Rapid scale-up of antiretroviral therapy (ART) and limited access to genotyping assays in low-resource settings (LRS) are inevitably accompanied by an increasing risk of HIV drug resistance (HIVDR). The current study aims to evaluate early warning indicators (EWI) as an efficient strategy to limit the development and spread of preventable HIVDR in these settings, in order to sustain the performance of national antiretroviral therapy (ART) rollout programmes. METHODS: Surveys were conducted in 2008, 2009 and 2010 within 10 Cameroonian ART clinics, based on five HIVDR EWIs: (1) Good prescribing practices; (2) Patient lost to follow-up; (3) Patient retention on first line ART; (4) On-time drug pick-up; (5) Continuous drug supply. Analysis was performed as per the World Health Organisation (WHO) protocol. RESULTS: An overall decreasing performance of the national ART programme was observed from 2008 to 2010: EWI(1) (100% to 70%); EWI(2) (40% to 20%); EWI(3) (70% to 0%); EWI(4) (0% throughout); EWI(5) (90% to 40%). Thus, prescribing practices (EWI(1)) were in conformity with national guidelines, while patient adherence (EWI(2), EWI(3), and EWI(4)) and drug supply (EWI(5)) were lower overtime; with a heavy workload (median ratio ≈1/64 staff/patients) and community disengagement observed all over the study sites. CONCLUSIONS: In order to limit risks of HIVDR emergence in poor settings like Cameroon, continuous drug supply, community empowerment to support adherence, and probably a reduction in workload by task shifting, are the potential urgent measures to be undertaken. Such evidence-based interventions, rapidly generated and less costly, would be relevant in limiting the spread of preventable HIVDR and in sustaining the performance of ART programmes in LRS.

Population-based monitoring of emerging HIV-1 drug resistance on antiretroviral therapy and associated factors in a sentinel site in Cameroon: low levels of resistance but poor programmatic performance.

BACKGROUND: Scale-up of antiretroviral therapy (ART) in resource-limited settings has drastically reduced HIV-related morbidity and mortality. However, challenges in long-term ART, adherence and HIV drug resistance (HIVDR) itself, require monitoring to limit HIVDR emergence among ART-experienced populations, in order to ensure regimen efficacy. METHODS: A longitudinal study was conducted from 2009-2011 in a cohort of 141 HIV-infected adult patients (aged >21) at the national social insurance centre hospital in Yaounde, Cameroon. As per-WHO HIVDR protocol, HIV-1 protease-reverse transcriptase genotyping was performed at baseline and at endpoint (12 months) on first-line ART using ViroSeq™ Genotyping kit. RESULTS: At baseline, a prevalence of 3.6% (5/139) HIVDR was observed [protease inhibitors M46I (1/5), G73A (1/5), L90LM (1/5); nucleoside reverse transcriptase inhibitors: M184V (1/5), T215F (1/5); non-nucleoside reverse transcriptase inhibitors: K103N (1/5), Y181Y/C (2/5), M230ML (1/5)]. At endpoint, 54.0% (76) patients were followed-up, 9.2% (13) died, and 3.5% (5) transferred, 38.5% (47) lost to follow-up (LTFU). 69.7% (53/76) of those followed-up had viremia <40 copies/ml and 90.8% (69/76) <1000 copies/ml. 4/7 patients with viremia ≥1000 copies/ml harbored HIVDR (prevalence: 5.3%; 4/76), with M184V/I (4/4) and K103K/N (3/4) being the most prevalent mutations. LTFU was favored by costs for consultation/laboratory tests, drug shortages, workload (physician/patient ratio: 1/180) and community disengagement. CONCLUSIONS: Low levels of HIVDR at baseline and at endpoint suggest a probable effectiveness of ART regimens used in Cameroon. However the possible high rate of HIVDR among LTFUs limited the strengths of our findings. Evaluating HIVDR among LTFU, improving adherence, task shifting, subsidizing/harmonizing costs for routine follow-up, are urgent measures to ensure an improved success of the country ART performance.