High prevalence of primary lamivudine and nelfinavir resistance in HIV-1-infected pregnant women in the United States, 1998-2004

Using a highly sensitive allele-specific polymerase chain reaction assay we detected the M184V mutation for lamivudine resistance in plasma from 9.4% of HIV-1-infected pregnant women enrolled in the Women and Infant Transmission Study between 1998 and 2004. The prevalence of nelfinavir resistance (D30N) was 6.3%. These results suggest a high prevalence of primary lamivudine and nelfinavir resistance among HIV-1-infected pregnant women in the United States, and support routine genotypic resistance testing before initiating mother-to-child-transmission prophylaxis. © 2007 Lippincott Williams & Wilkins, Inc.