 i To determine the HIV infection rate of infants as measured of a sample collected within 72 hours of birth; ii To determine the HIV transmission incidence attributable to the duration of different feeding practices; iii To determine the cumulative incidence of vertical transmission in EBF, MBF and EFF infants; iv To describe risk factors, other than feeding practice, for post-natal transmission of HIV, including maternal and infant morbidity and breast health; v To assess the determinants of transmission in MBF adjusting for exposure factors e.g. type and age of introduction of other foodmilk; vi To describe the morbidity and growth of infants in relation to feeding practices and HIV status; and vii To describe adherence rates to EBF following a breastfeeding support intervention. 