Pediatric SARS-CoV-2, MIS-C Differed in Delta, Omicron Waves

THURSDAY, Jan. 26, 2023 (HealthDay News) — The clinical presentation of hospitalized children with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-positive testing or multisystem inflammatory syndrome in children (MIS-C) differed in the delta and omicron waves, according to a study published online Jan. 7 in Viruses.

Patrick O. Kenney, M.D., from the Jacobs School of Medicine and Biomedical Sciences at the University at Buffalo in New York, and colleagues conducted a retrospective cohort study with case adjudication of hospitalized children with SARS-CoV-2-positive testing or an MIS-C diagnosis during the delta and omicron waves (August 2021 to February 2022) to describe differences in clinical presentation.

The researchers found no differences by race, but Black children were disproportionately affected in both waves (24 and 25 percent). In the omicron wave, incidental diagnoses were higher (34 versus 19 percent). In addition, hospitalization rates of nonincidental cases were also higher during omicron versus delta (5.9 versus 3.8 per 1,000 polymerase chain reaction-positive community cases). During delta, respiratory-related admissions were prominent, while clinical presentations varied during omicron, including a high number of cases of croup and seizures. Compared with during delta, length of stay and intensive care unit use were significantly lower for MIS-C and acute cases during omicron. In the early omicron period, the estimated vaccine efficacy for preventing hospital admissions was 85.1 to 91.7 percent.

“Since the symptomatology of presentations is evolving, the suspicion for COVID-19 as a causative agent in pediatric hospitalizations should remain high, even in patients without typical respiratory symptoms,” the authors write.