There have been limited studies evaluating temporal changes in the incidence of detection of drug resistance among human immunodeficiency virus type 1 (HIV-1) isolates and concomitant changes in plasma HIV load for treated individuals in a population-wide setting.
Longitudinal plasma viral load and genotypic resistance data were obtained from patients receiving antiretroviral therapy from the British Columbia Drug Treatment Program from July 1996 through December 2008. A total of 24,652 resistance tests were available from 5422 individuals. The incidence of successful plasma viral load suppression and of resistance to each of 3 antiretroviral categories (nucleoside/nucleotide reverse-transcriptase inhibitors, nonnucleoside reverse transcriptase inhibitors, and protease inhibitors) was calculated for the population receiving therapy.
There has been a drastic decrease in the incidence of new cases of HIV-1 drug resistance in individuals followed during 1996-2008. In 1997, the incidence rate of any newly detected resistance was 1.73 cases per 100 person-months of therapy, and by 2008, the incidence rate had decreased >12-fold, to 0.13 cases per 100 person-months of therapy. This decrease in the incidence of resistance has occurred at an exponential rate, with half-times on the order of 2-3 years. Concomitantly, the proportion of individuals with plasma viral load suppression has increased linearly over time (from 64.7% with HIV RNA levels
Cites: J Infect Dis. 2005 Feb 1;191(3):339-4715633092
Cites: AIDS Res Hum Retroviruses. 2008 Jan;24(1):43-5118275347