Prevalence and correlates of HIV among children born to HIV-negative mothers in Zambia: a secondary analysis of the 2024 Zambia Demographic and Health Survey

Despite substantial progress in preventing mother-to-child transmission (PMTCT) of HIV in Zambia, HIV infection among children whose mothers test HIV-negative represents an understudied phenomenon that may reflect non-vertical transmission pathways. This cross-sectional secondary analysis of the 2024 Zambia Demographic and Health Survey (ZDHS) examined the prevalence and correlates of HIV among children aged 2-14 years whose mothers tested HIV-negative. Children with valid HIV blood test results were linked to their co-resident mothers HIV test results using household-level identifiers. HIV prevalence with 95% confidence intervals was estimated by age group, sex, residence, province, and wealth quintile. Bivariate associations were assessed using chi-square tests and odds ratios. Among 13,960 children of HIV-negative mothers, 69 (0.49%; 95% CI: 0.39%-0.63%; weighted: 0.58%) tested HIV-positive. Prevalence varied substantially by province (p < 0.001), with Copperbelt Province exhibiting the highest burden at 2.97%. Urban children had significantly higher prevalence than rural children (1.10% vs. 0.26%; OR = 3.68, 95% CI: 2.25-6.03, p < 0.001). A paradoxical wealth gradient was observed, with children in richer households showing higher prevalence than those in the poorest households (OR = 4.93, 95% CI: 2.19-11.10, p < 0.001). Maternal education was marginally associated with child HIV status (p = 0.04). Neither child sex (p = 0.10) nor age group (p = 0.29) was significantly associated with HIV positivity. A substantial proportion of HIV-positive children in Zambia have HIV-negative mothers, highlighting important gaps in the current PMTCT-focused paradigm and calling for expanded prevention strategies that address transmission risks beyond vertical transmission.