Abstract

Single-dosed nevirapine (NVP), which frequently selects for resistant virus, is still often applied in resource-limited settings to prevent vertical human immunodeficiency virus (HIV) transmission. We followed-up 83 NVP-exposed HIV-positive mothers and newborns between delivery and 18 months postpartum, testing for vertical transmission and for common NVP-selected resistance mutations through highly sensitive allele-specific polymerase chain reaction (PCR). Ten infants turned seropositive within 18 months; 9 mother-child-pairs were available for resistance testing. Mutations were detected in plasma virus of 7/9 (78%) mothers and 4/9 (44%) infants. Resistant virus predominantly emerged at 2 to 8 weeks after NVP-exposure. NVP resistant HIV-1 variants did not persist longer in infants than in their mothers; however, the success of non-nucleoside reverse transcriptase inhibitors (NNRTI)-containing treatment might be limited for HIV-infected infants if initiated within 6 months after NVP exposure.

Key words: Human immunodeficiency virus (HIV), preventing mother-to-child transmission (PMTCT), nevirapine (NVP), resistance, antiretroviral treatment (ART) initiation, paediatric ART.