Association between SARS-CoV-2 infection before the age of two and child development

To compare the differences in child development between children who contracted COVID-19 after February 1st, 2022, the period when the B.1.1.529 variant outbreak began to peak in Thailand, and those who did not. A prospective cohort study was conducted in an outpatient pediatric clinic at a tertiary hospital in southern Thailand. COVID-19 was diagnosed based on the results of an FDA-approved antigen test or RT-PCR using a swab sample collected from the nasopharynx, nose, or throat. Child development was assessed using the Ages and Stages Questionnaire, Third Edition (ASQ-3). Of the 336 participants, 180 (53.6%) had a history of COVID-19. Almost all of them had mild COVID-19. The mean (SD) age at infection was 1.3 (0.3) years, and the median (IQR) duration between infection and ASQ-3 assessment was 193.5 (167.8, 216.2) days. The ASQ-3 scores at the ages of 18 (n = 166; 90 COVID-19 positive) and 24 months (n = 170; 90 COVID-19 positive) revealed no statistically significant differences between children with and without a history of COVID-19. Both groups had comparable proportions of developmental scores