What policymakers should know about drug resistance and adherence in the context of scaling-up treatment of HIV infection.

With the imminent massive scale up of antiretroviral therapy in developing countries concerns have been raised regarding the spectre of widespread viral drug resistance. These concerns should not lead to a slowing of the pace at which these life-preserving medications are made available to the millions in need in those countries. With proper HAART regimens and proper adherence, development of drug resistance is not a common event. Increasing simplicity of antiretroviral drug regimens, as well as supportive services, promote adherence and have been shown to lead to extremely high therapeutic success rates in both developed and developing countries. Moreover, the possibility of drug resistance has not discouraged industrialized countries from offering universal access to antiretrovirals. If anything, the situation in developing countries, where few patients have been previously exposed to suboptimal drug regimens and where a public health approach may be taken to the treatment of HIV infection, is in many respects more favourable to the prevention of widespread viral drug resistance than that in the developed world. This conclusion is underscored by available evidence presented in this supplement. Experience in developing countries also suggests that greater treatment access will help alleviate HIV-related stigma and provide major new incentives for individuals to learn their serostatus, thus strengthening prevention efforts.