Background The epidemiology of HIV in children in sub-Saharan Africa remains poorly understood. To help address this gap we describe the prevalence, causes and effects of HIV in children (aged 2–14 years) and adolescents (aged 15–17 years) in a southern African population.

Methods General population survey of 3,390 children and 2,130 adolescents in Manicaland, eastern Zimbabwe. Data on possible socio-demographic correlates of HIV prevalence, sources of infection, and effects of HIV infection in children were analysed using multi-variable logistic regression. The contribution of horizontal transmission was assessed by investigating the survival and HIV infection status of mothers of infected children.

Results HIV prevalence was 2.15% (73/3,390) in children and 1.97% (42/2,130) in adolescents. Infection levels did not differ by sex, age, socio-economic status, location or religion. The mothers of most infected children were either deceased or HIV-positive which is consistent with MTCT being the primary mode of infection, but 9/73 infected children and 4/42 infected adolescents had surviving uninfected mothers. Infected children were more likely than uninfected children to be malnourished (21.6% versus 9.9%, p = 0.006) and stunted (42.0% versus 30.5%, p = 0.03). HIV infection was not correlated with physical or psychological ill-health in children, but infected adolescents were more likely to report episodes of illness than their uninfected counterparts (p = 0.003).

Conclusion Childhood HIV infection in Zimbabwe is due primarily to MTCT and is associated with poor physical development.