Among people with HIV living in resource-limited settings, 93% had at least one mutation associated with resistance to nucleoside reverse transcriptase inhibitors, according to data from a recent study.
In addition, 96% of the people had at least one mutation associated with resistance to non-nucleoside reverse transcriptase inhibitors (NNRTI).
“The low genetic barrier and high level resistance of NNRTI anchored regimens in the absence of frequent [viral load] monitoring results in a rapid accumulation of drug resistance mutations to NNRTI and NRTI drugs that may limit future treatment options,” the researchers wrote in Clinical Infectious Diseases.
The researchers tested for HIV drug resistance among plasma samples taken from patients with suspected treatment failure of first-line antiretroviral therapy. The patients were part of the A5230 study conducted in Thailand, South Africa, India, Malawi and Tanzania. Among the 207 patients screened for the trial, sequencing data were available for 148. The median viral load at screening was 4.4 log10 copies/mL and the median CD4 count was 155 cells/mm3.
Higher viral load and lower CD4 count were significantly associated with the number of NRTI mutations. Those with viral load of more than 5 log10 copies/mL had a median of five NRTI mutations. The number of mutations varied by study site. The presence of NNRTI mutations also was associated with a higher viral load, and the median number of NNRTI mutations was 2.5. NNRTI mutations did not vary by study site.
“Implementation of [viral load] monitoring could reduce the duration of exposure to a failing regimen and therefore retain enhanced options for future lines of therapy,” the researchers wrote.
Disclosure: The researchers report no relevant financial disclosures.