Human immunodeficiency virus load in breast milk, mastitis, and mother-to-child transmission of human immunodeficiency virus type 1

Human immunodeficiency virus (HIV) type 1 load in breast milk and mastitis were examined as risk factors for vertical transmission of HIV-1, Six weeks after delivery, HIV-1 load and sodium (an indicator of mastitis) were meas ured in breast milk from 334 HIV-l-infected women in Malawi, Median breast milk HIV-1 load was 700 copies/mL among women with HIV-1-infected infants v ersus undetectable (<200 copies/mL) among those with uninfected infants, re spectively (P<.0001). Elevated breast milk sodium levels consistent with ma stitis occurred in 16.4% of HIV-1-infected women and were associated with i ncreased vertical transmission of HIV-1 (P<.0001), Median breast milk HIV-1 load was 920 copies/mL among women with versus undetectable among those wi thout elevated breast milk sodium levels, respectively (P<.0001), Mastitis and breast milk HIV-1 load may increase the risk of vertical transmission o f HIV-1 through breast-feeding.