Timing of perinatal human immunodeficiency virus type 1 infection and rateof neurodevelopment

Background. Identifying HIV-1-infected children who are at greatest risk fo r disease-related morbidities is critical for optimal therapeutic as well a s preventive care. Several factors have been implicated in HIV-1 disease on set and severity, including maternal and infant host characteristics, viral phenotype and timing of HIV-1 infection. Early HIV-1 culture positivity, i .e. intrauterine infection, has been associated with poor immunologic, viro logic and clinical outcomes in children of HIV-infected women. However, a d irect effect of timing of infection on neurodevelopmental outcome in infanc y has not yet been identified. Methods. Serial neurodevelopmental assessments were performed with 114 infa nts vertically infected with HIV-1 in a multicenter natural history, longit udinal study. Median mental and motor scores were compared at three time po ints. Longitudinal regression analyses were used to evaluate the neurodevel opmental functioning of children with early positive cultures and those wit h late positive cultures. Results. Early infected infants scored significantly lower than late infect ed infants by 24 months of age and beyond on both mental (P = 0.05) and mot or (P = 0.03) measures. Early HIV-1 infection was associated with a decline in estimated motor scores of 1 standard score point per month compared wit h 0.28 point in the late infected group (P < 0.02). Estimated mental. score s of the early infected group declined 0.72 point/month, whereas the averag e decline of the late infected group was 0.30 point/month (P < 0.13). Conclusion. Early HIV-1 infection increases a child's risk for poor neurode velopmental functioning within the first 30 months of life.