RESUMO
Short-course zidovudine (ZDV) with or without a single dose of nevirapine (sdNVP) is widely used to prevent mother-to-child HIV transmission (PMTCT). However, more data on viral load in breast milk following pMTCT regimens are needed. In a randomized PMTCT study in Botswana, in which half of the women received sdNVP in labor, stored samples from mothers assigned to breastfeed were analyzed for HIV-1 RNA in breast milk supernatant. A total of 527 samples from 282 women, collected at delivery, 2 weeks, 2 months, and 5 months postpartum were available for testing. Cell-free breast milk HIV-1 RNA was detectable (>40 copies/ml) in 44.8% (236/527) of samples analyzed. Women randomized to sdNVP + ZDV were more likely to have undetectable breast milk viral loads at 2 weeks postpartum compared with those who received ZDV alone (67.8% vs. 38.5%, p = 0.002). By 2 months postpartum the difference between study arms disappeared, and 43.8% of women who received sdNVP + ZDV had undetectable HIV-1 RNA compared to 53.8% of the ZDV alone group (p = 0.19) and 60.5% vs. 64.5%, respectively, at month 5 (p = 0.61.) The addition of sdNVP to antenatal short-course AZT resulted in significantly reduced breast milk viral loads at 2 weeks postpartum suggesting a reduced risk of MTCT during the early postpartum period. However, viral loads in both study arms were comparable at 2 and 5 months postpartum, suggesting that the receipt of sdNVP in labor may defer rather than blunt the postpartum viral load rebound seen in breast milk after the discontinuation of ZDV.
Assuntos
Fármacos Anti-HIV/administração & dosagem , Infecções por HIV/prevenção & controle , HIV-1/efeitos dos fármacos , Transmissão Vertical de Doenças Infecciosas/prevenção & controle , Leite Humano/virologia , Nevirapina/administração & dosagem , Período Pós-Parto/efeitos dos fármacos , Carga Viral/efeitos dos fármacos , Aleitamento Materno/efeitos adversos , Feminino , Infecções por HIV/transmissão , Infecções por HIV/virologia , Humanos , Zidovudina/uso terapêuticoRESUMO
Human immunodeficiency virus type 1 subtype C (HIV-1C) accounts for about 50% of all HIV infections in the pandemic and is the predominant subtype in the heavily burdened region of southern Africa. HIV-1C possesses unique genetic and phenotypic features that might be associated with biological differences compared to other subtypes. Here, we generated virus isolates from individuals at different stages of HIV-1C infection and investigated the chemokine receptor repertoire that the derived HIV-1C isolates may utilize for entry. Our results show that the R5 phenotype predominates among viruses in Botswana, with a lesser contribution of viruses showing the dualtropic X4R5 phenotype. No viruses of pure X4 phenotype were found, which suggests no discernable evolution of HIV-1C to a monotropic X4 phenotype as the epidemic ages in Botswana. Usage of other coreceptors was rare and apparently insignificant. These results enhance our understanding of HIV-1C biology, with implications for designing and testing therapeutic and prophylactic agents.