title: 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.
abstract: 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.
authors.affiliation: National HIV Drug Resistance Prevention and Surveillance Working Group, Yaounde, Cameroon.
authors.forename: Serge C
authors.initials: SC
authors.lastname: Billong
authors.forename: Joseph
authors.initials: J
authors.lastname: Fokam
authors.forename: Avelin F
authors.initials: AF
authors.lastname: Aghokeng
authors.forename: Pascal
authors.initials: P
authors.lastname: Milenge
authors.forename: Etienne
authors.initials: E
authors.lastname: Kembou
authors.forename: Ibile
authors.initials: I
authors.lastname: Abessouguie
authors.forename: Flore Beatrice
authors.initials: FB
authors.lastname: Meva'a-Onglene
authors.forename: Anne C Zoung-Kanyi
authors.initials: AC
authors.lastname: Bissek
authors.forename: Vittorio
authors.initials: V
authors.lastname: Colizzi
authors.forename: Eitel N
authors.initials: EN
authors.lastname: Mpoudi
authors.forename: Jean-Bosco N
authors.initials: JB
authors.lastname: Elat
authors.forename: Koulla S
authors.initials: KS
authors.lastname: Shiro
mesh_terms: D000328:Adult; D019380:Anti-HIV Agents / Q000627:therapeutic use*; D002163:Cameroon; D024882:Drug Resistance, Viral; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000821:virology; D015497:HIV-1 / Q000187:drug effects*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D011446:Prospective Studies; D018571:Sentinel Surveillance; D055815:Young Adult
chemical_list: D019380:Anti-HIV Agents