Hidden drug resistant HIV to emerge in the era of universal treatment access in Southeast Asia.

Hidden drug resistant HIV to emerge in the era of universal treatment access in Southeast Asia.

Universal access to first-line antiretroviral therapy for HIV infection is becoming more of a reality in most low and middle income countries in Asia. However, second-line therapies are relatively scarce. Hoare and colleagues developed a mathematical model of an HIV epidemic in a Southeast Asian setting and used it to forecast the impact of treatment plans, without second-line options, on the potential degree of acquisition and transmission of drug resistant HIV strains. They show that after 10 years of universal treatment access, up to 20% of treatment-naïve individuals with HIV may have drug-resistant strains but it depends on the relative fitness of viral strains. If viral load testing of people on antiretroviral therapy is carried out on a yearly basis and virological failure leads to effective second-line therapy, then transmitted drug resistance could be reduced by 80%. Greater efforts are required for minimizing first-line failure, to detect virological failure earlier, and to procure access to second-line therapies.

In many low- and middle-income settings around the world, treatment failure is diagnosed based on clinical symptoms only, without immunological information, let alone viral load tests or resistance testing. Late diagnosis of treatment failure translates into increased risk of disease progression for the individual and increased risk that sexual partners, injecting partners, or infants will acquire transmitted resistance. Resistance has developed to all currently-licensed antiretroviral drugs since the first report in 1993. This modelling work assumes differential viral fitness for the majority-resistant strains that are detectable using conventional nucleotide sequencing after polymerase chain reaction (PCR) amplification, compared to minority-resistant strains that can only be detected by advanced real time (PCR) assays. It reveals the tremendous benefits of even biannual (once every two years) viral load testing. The prevalence of transmitted drug resistance would fall 50% with biannual testing, 80% with annual testing, and 90% with quarterly testing. In the era of universal access and with a renewed emphasis on the five pillars of treatment 2.0 (create a better pill and diagnostics, treatment as prevention, stop cost being an obstacle, improve uptake of voluntary HIV testing and counselling and linkages to care, and strengthen community mobilization), we must keep the issue of access to cheap, accurate, accessible viral load monitoring on the front burner, along with access to second line regimens. The legacy of not doing so will live on well beyond us.