Lucile Packard Children’s Hospital Stanford … During the nine-month period, 117 patients under the age of 18 either tested positive for SARS-CoV-2 at the hospital or were hospitalized for [MIS-C]. Out of the 117 children, nearly 40% of COVID-19 cases were asymptomatic, according to the study published Wednesday in the peer-reviewed journal Hospital Pediatrics. About 45% of those hospital admissions were categorized as unlikely to be caused by the virus.