Virological outcome and patterns of HIV-1 drug resistance in patients with 36 months' antiretroviral therapy experience in Cameroon.
Journal - Journal of the International AIDS Society (Switzerland )
Introduction: The current expansion of antiretroviral treatment (ART) in the developing world without routine virological monitoring still raises concerns on the outcome of the strategy in terms of virological success and drug resistance burden. We assessed the virological outcome and drug resistance mutations in patients with 36 months' ART experience, and monitored according to the WHO public health approach in Cameroon. Methods: We consecutively recruited between 2008 and 2009 patients attending a national reference clinic in Yaoundé - Cameroon, for their routine medical visits at month 36±2. Observance data and treatment histories were extracted from medical records. Blood samples were collected for viral load (VL) testing and genotyping of drug resistance when HIV-1 RNA=1000 copies/ml. Results: Overall, 376 HIV-1 infected adults were recruited during the study period. All, but four who received PMTCT, were ART-naïve at treatment initiation, and 371/376 (98.7%) started on a first-line regimen that included 3TC +d4T/AZT+NVP/EFV. Sixty-six (17.6%) patients experienced virological failure (VL=1000 copies/ml) and 53 carried a resistant virus, thus representing 81.5% (53/65) of the patients who failed. Forty-two out of 53 were resistant to nucleoside and non-nucleoside reverse-transcriptase inhibitors (NRTIs+NNRTIs), one to protease inhibitors (PI) and NNRTIs, two to NRTIs only and eight to NNRTIs only. Among patients with NRTI resistance, 18/44 (40.9%) carried Thymidine Analog Mutations (TAMs), and 13/44 (29.5%) accumulated at least three NRTI resistance mutations. Observed NNRTI resistance mutations affected drugs of the regimen, essentially nevirapine and efavirenz, but several patients (10/51, 19.6%) accumulated mutations that may have compromised etravirine use. Conclusions: We observed a moderate level of virological failure after 36 months of treatment, but a high proportion of patients who failed developed drug resistance. Although we found that for the majority of patients, second-line regimens recommended in Cameroon would be still effective, accumulated resistance mutations are of concern and may compromise future treatment strategies, stressing the need for virological monitoring in resource-limited settings.
|ISSN : ||1758-2652|
|Keywords : ||Cameroon HIV-1 drug resistance resource-limited country treatment outcome virological monitoring|
High failure rate of ViroSeqTM HIV-1 Genotyping System for drug resistance testing in Cameroon, a context of broad HIV-1 genetic diversity.
Journal - Journal of clinical microbiology
The ViroSeq(TM) HIV-1 Genotyping System is used in many African countries for drug resistance testing. In this report, we showed on a panel of diverse HIV-1 group M isolates circulating in Cameroon that the performance of this assay can be altered by the sequence variation of non-B HIV-1 strains that predominate in African settings.
Evaluation of transmitted HIV drug resistance among recently-infected antenatal clinic attendees in four Central African countries.
Journal - Antiviral therapy (England )
BACKGROUND: The rapid expansion of antiretroviral treatment in resource-limited settings is raising concerns regarding the emergence and transmission of HIV drug resistance (HIVDR). We evaluated the extent of transmission of drug-resistant HIV strains in four Central African countries: the Republic of Congo, Central African Republic, Chad and Cameroon. METHODS: The World Health Organization (WHO) HIVDR threshold survey was implemented in major treatment areas in each country. Pregnant women who were aged <25 years, who were at first pregnancy and who were HIV type-1-positive were enrolled at each site in 2006-2007 for genotyping. HIVDR prevalence was categorized using the WHO threshold survey binomial sequential sampling method. RESULTS: The prevalence of HIVDR in Brazzaville and Bangui sites could not be classified because the eligible sample number was not reached. HIVDR prevalence was low (<5%) in N'Djamena for all drug classes. In Yaoundé, we found one individual with the D67D/N mutation and two with K103N. HIVDR prevalence was categorized as low (<5%) for protease inhibitors (PIs) and nucleoside reverse transcriptase inhibitors (NRTIs), and moderate (> or =5-< or =15%) for non-NRTIs (NNRTIs). HIVDR prevalence in Douala was low for PIs and NNRTIs, and moderate for NRTIs as we identified one individual with M184V plus K101E plus G190A mutations and a second with D67D/N. CONCLUSIONS: The moderate HIVDR prevalence found in Yaoundé and Douala indicate that efforts should be made in Cameroon to prevent HIVDR; however, additional surveys are needed to confirm this trend. This study highlighted challenges presented by the WHO methodology, such as additional costs, workload, difficulties in acquiring even small sample numbers and the necessity for better quality assurance of HIV testing and record keeping at antenatal clinics.
|ISSN : ||1359-6535|
|Mesh Heading : ||Adolescent Adult Africa, Central Anti-HIV Agents Data Collection Female HIV Infections HIV Protease Inhibitors HIV-1 Humans Mutation Pregnancy Prevalence Program Evaluation Reverse Transcriptase Inhibitors World Health Organization epidemiology therapeutic use methods drug therapy virology pharmacology therapeutic use genetics pharmacology therapeutic use|
|Mesh Heading Relevant : ||Drug Resistance, Multiple, Viral pharmacology epidemiology transmission drug effects|