Infectious morbidity among children HIV-exposed uninfected in South Africa: elevated risk in infancy but not thereafter.

Abstract

Background: Increased risk of infectious morbidity and hospitalisation has been reported during infancy among children HIV-exposed uninfected (CHEU) compared to children HIV-unexposed uninfected (CHUU). However, data on risks beyond infancy are limited.

Methods: We enrolled pregnant women with and without HIV from a primary healthcare facility in a lower-income area in Cape Town, South Africa (2017-2018). We tracked their children's HIV test results and hospitalisations using routine electronic healthcare data. We previously reported increased rates of infectious-cause hospitalisation among CHEU in the first year of life, and now extend the analysis to cover the period from age 1 to <5 years. Using random-effects Poisson regression, we calculated adjusted incidence rate ratios (aIRR) for infectious-cause hospitalisation among CHEU vs CHUU, clustered by infant and adjusted for child sex and vaccination status, maternal age and education, and housing type.

Results: Among 446 CHEU and 455 CHUU, 147 admissions occurred from age 1 to <5 years; with 59% (n = 87) due to infections. All-cause hospitalisation occurred in 9.2% of CHEU and 10.5% of CHUU; infectious-cause hospitalisation occurred in 6.5% of CHEU and 7.3% of CHUU with crude incidence rates of 2.4 per 100 child-years for both groups (IRR = 1.0; 95% CI 0.6-1.6). Adjusted analyses showed no evidence of increased hospitalisation among CHEU (aIRR = 0.71; 95% CI 0.36-1.41).

Conclusions: Elevated risk of infectious-cause hospitalisation among CHEU did not persist beyond the first year of life. These findings highlight infancy as a key window for targeted interventions, while providing reassurance regarding longer-term infectious morbidity risk.