Low frequency of the V106M mutation among HIV-1 subtype C-infected pregnant women exposed to nevirapine

Nevirapine used in single doses to prevent mother-to-child transmission has been shown to be associated with the development of transient resistant mutations. Here we describe the presence of V106M in seven out of 141 South African women (5%) 6 weeks after receiving nevirapine. V106M is a novel resistance mutation found in subtype C viruses exposed to efavirenz. This mutation is thus also induced at a low frequency in subtype C viruses exposed to single dose nevirapine.