Rates of emergence of HIV drug resistance in resource-limited settings: a systematic review

Abstract

Background: The increasing availability of antiretroviral therapy (ART) has improved survival and quality of life for many infected with HIV, but can also engender drug resistance. This review summarizes the available information on drug resistance in adults in resource-limited settings.

Methods: The online databases PubMed and Google Scholar, pertinent conference abstracts and references from relevant articles were searched for publications available before November 2011. Data collected after ART rollout were reviewed.

Results: A total of 7 studies fulfilled the criteria for the analysis of acquired drug resistance and 22 fulfilled the criteria for the analysis of transmitted drug resistance (TDR). Acquired resistance was detected in 7.2% of patients on ART for 6-11 months, 11.1% at 12-23 months, 15.0% at 24-35 months, and 20.7% at ≥ 36 months. Multi-class drug resistance increased steadily with time on ART. The overall rate of TDR in all resource-limited countries studied was 6.6% (469/7,063). Patients in countries in which ART had been available for ≥ 5 years were 1.7 × more likely to have TDR than those living in a country where ART had been available for <5 years (P<0.001). The reported prevalence of TDR was 5.7% (233/4,069) in Africa, 7.6% (160/2,094) in Asia and 8.4% (76/900) in Brazil.

Conclusions: The emergence of drug resistance following access to ART in resource-limited settings resembles what was seen in resource-rich countries and highlights the need for virological monitoring for drug failure, drug resistance testing and alternative drug regimens that have proven beneficial in these resource-rich settings.

Conflict of interest statement

Conflicts of interest

There are no conflicts of interest to be reported.

Figures

Figure 1. Search Strategy

MSM=men who have sex with men. aStudies with no drug resistance prevalence data, studies conducted in non-resource limited areas, studies of prevention of mother-to-child transmission, studies involving patients on non-highly active antiretroviral therapy regimens, medication adherence studies, and studies not in English.

Figure 2. Changes in rates of acquired HIVDR to any drug class according duration of treatment

HIVDR=human immunodeficiency virus drug resistance. ART=antiretroviral therapy.

Figure 3. Distribution of acquired HIVDR to individual drug classes according to time on antiretroviral therapy

Drug-class resistance information was not available for all studies. Percentages given were calculated using only the studies which gave drug-class specific information, causing them to be of different proportions than the overall resistance rates presented in figure 2. HIVDR=human immunodeficiency virus drug resistance. ART=antiretroviral therapy. NRTI=nucleoside reverse transcriptase inhibitor. NNRTI=non-nucleoside reverse transcriptase inhibitor. PI=protease inhibitor.

Figure 4. Changes in rates of transmitted HIVDR according to time since ART availability

HIVDR=human immunodeficiency virus drug resistance. ART=antiretroviral therapy. NRTI=nucleoside reverse transcriptase inhibitor. NNRTI=non-nucleoside reverse transcriptase inhibitor. PI=protease inhibitor.