Transmitted drug resistance in nonsubtype B HIV-1 infection

Abstract

HIV-1 nonsubtype B variants account for the majority of HIV infections worldwide. Drug resistance in individuals who have never undergone antiretroviral therapy can lead to early failure and limited treatment options and, therefore, is an important concern. Evaluation of reported transmitted drug resistance (TDR) is challenging owing to varying definitions and study designs, and is further complicated by HIV-1 subtype diversity. In this article, we discuss the importance of various mutation lists for TDR definition, summarize TDR in nonsubtype B HIV-1 and highlight TDR reporting and interpreting challenges in the context of HIV-1 diversity. When examined carefully, TDR in HIV-1 non-B protease and reverse transcriptase is still relatively low in most regions. Whether it will increase with time and therapy access, as observed in subtype-B-predominant regions, remains to be determined.

Figure 1. HIV-1 global diversity as reported in studies included in this article

Data are based on references cited in Table 2, as well as others with subtype B data [,–150]. Colors indicate predominate subtype(s) in a given region based on those studies and do not necessarily include all subtypes epidemiologically reported from that region. Subtypes referred to as ‘other’ indicate numerous recombinant forms and/or a low prevalence of other subtypes. *Reports of subtypes from these regions are limited. Current data suggest existence of many different subtypes and recombinant forms with no specific predominating species. CRF: Circulating recombinant form.