Non-B HIV-1 subtypes in sub-Saharan Africa: impact of subtype on protease inhibitor efficacy.

In 2012, 25 million people [71% of global human immunodeficiency virus (HIV) infection] were estimated to be living with HIV in sub-Saharan Africa. Of these, approximately 1.6 million were new infections and 1.2 million deaths occurred. South Africa alone accounted for 31% of HIV/acquired immunodeficiency syndrome (AIDS) deaths in sub-Saharan Africa. This disturbing statistic indicates that South Africa remains the epicenter of the HIV/AIDS pandemic, compounded by the fact that only 36% of HIV-positive patients in South Africa have access to antiretroviral (ARV) treatment. Drug resistance mutations have emerged, and current ARVs show reduced efficacy against non-B subtypes. In addition, several recent studies have shown an increased prevalence of non-B African HIV strains in the Americas and Europe. Therefore, the use of ARVs in a non-B HIV-1 subtype context requires further investigation. HIV-1 subtype C protease, found largely in sub-Saharan Africa, has been under-investigated when compared with the subtype B protease, which predominates in North America and Europe. This review, therefore, focuses on HIV-1 proteases from B and C subtypes.