Change in HIV-related characteristics of children hospitalised with infectious diseases in Western Cape, South Africa, 2008-2021: a time trend analysis.

INTRODUCTION: With the scaling up of vertical HIV transmission prevention programmes, the HIV-related population profile of children in South Africa has shifted. We described temporal changes in HIV-related characteristics of children, aged ≤3 years (up to the third birthday), with infectious disease hospitalisations across the Western Cape province.

METHODS: We used routinely collected electronic data to identify children born in the Western Cape with infectious disease hospital records for lower respiratory tract infections, diarrhoea, meningitis and tuberculous meningitis, from 2008 to 2021. Linked maternal and child unique identifiers were used to extract pregnancy, HIV-related, laboratory, pharmacy and hospitalisation data. We described temporal changes in child HIV exposure and acquisition status, timing of maternal HIV diagnosis and antiretroviral therapy (ART) start, infant exposure to maternal ART and timing thereof, and maternal CD4 and HIV viral load closest to delivery. We used logistic and multinomial regression to assess changes in characteristics between the Pre-Option B+ (2008-2013), Option B+ (2013-2016) and Universal ART periods (2016-2021).

RESULTS: Among 52,811 children aged ≤3 years with hospitalisations, the proportion living with HIV dreased from 7.0% (2008) to 1.1% (2021), while those exposed to HIV and uninfected increased from 14.0% (2008) to 16.1% (2021) with a peak of 18.3% in 2017. Among mothers with HIV (n = 9873), the proportion diagnosed with HIV and starting ART before pregnancy increased from 20.2% to 69.2% and 5.8% to 59.0%, respectively, between 2008 and 2021. Children hospitalised during the Universal ART period had eight times higher odds (Odds Ratio: 8.41; 95% CI: 7.36-9.61) of exposure to maternal ART versus children admitted Pre-Option B+. Among mothers of children exposed to HIV and uninfected with CD4 records (n = 7523), the proportion with CD4 <350 cells/μl decreased from 90.6% (2008) to 27.8% (2021).

CONCLUSIONS: In recent years, among children hospitalised with infectious diseases, there were fewer children with perinatally acquired HIV, while an increased proportion of those without HIV acquisition are exposed to maternal HIV and ART. There is a need to look beyond paediatric HIV prevalence and consider child exposure to HIV and ART among children without HIV, when assessing the HIV epidemic's impact on child health services.