The ability of HIV to mutate and reproduce itself in the presence of antiretroviral drugs is called HIV drug resistance. The consequences of drug resistance include treatment failure, increased direct and indirect health costs associated with the need to start more costly second-line treatment for patients, the spread of resistant strains of HIV and the need to develop new anti-HIV drugs. The extent of HIV drug resistance resulting from recent ART scale up in resource-limited countries has not systematically been quantified due to the lack of reliable data and information.
WHO and its HIV ResNet group of experts and organizations have developed a Global strategy for prevention and assessment of HIV drug resistance. The strategy aims to build evidence on the scale of HIV drug resistance and equip and prepare countries with knowledge, skills and systems to respond should drug-resistant HIV epidemics emerge.