Risk Factors for Severe COVID‐19 Among Children and Adolescents Enrolled in Acute Respiratory Infection Sentinel Surveillance in South Africa, 2020–2022

ABSTRACT Background Identifying children at risk for severe COVID‐19 disease from severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) may guide future mitigation interventions. Using sentinel surveillance data, we aimed to identify risk factors for SARS‐CoV‐2–associated hospitalisation among patients aged ≤ 18 years with respiratory illness. Methods From April 2020 to March 2022, patients meeting study case definitions were enrolled at four outpatient influenza‐like illness (ILI) and five inpatient severe respiratory infection (SRI) surveillance sites and tested for SARS‐CoV‐2 infection using polymerase chain reaction (PCR). Each ILI clinic shared a catchment area with its corresponding SRI hospital. Potential risk factors for SARS‐CoV‐2–associated hospitalisation were analysed using multivariable logistic regression by comparing inpatient versus outpatient SARS‐CoV‐2 cases. Results Of 4688 participants aged ≤ 18 years, 4556 (97%) with complete PCR and HIV data were included in the analysis. Among patients with ILI and SRI, 92/1145 (8%) and 154/3411 (5%) tested SARS‐CoV‐2 positive, respectively. Compared to outpatients, hospitalised SARS‐CoV‐2 cases were associated with age < 6 months (adjusted odds ratio (aOR) 8.0, 95% confidence interval (CI) 2.7–24.0 versus 1–4 years); underlying medical condition other than HIV aOR 5.8, 95% CI 2.3–14.6; laboratory‐confirmed Omicron BA.1/BA.2 or Delta variant (aOR 4.9, 95% CI 1.7–14.2 or aOR 2.8, 95% CI 1.1–7.3 compared to ancestral SARS‐CoV‐2); and respiratory syncytial virus coinfection aOR 6.2, 95% CI 1.0–38.5. Conclusion Aligning with previous research, we identified age < 6 months or having an underlying condition as risk factors for SARS‐CoV‐2–associated SRI hospitalisation and demonstrated the potential of sentinel surveillance to monitor COVID‐19 in children.