Human Rhinovirus as a Cause of Fever in Neonates and Young Infants During the COVID-19 Pandemic, 2020-2022.

Abstract

Human rhinovirus (HRV) was predominant and persistent during the coronavirus disease 2019 (COVID-19) pandemic despite nonpharmaceutical interventions. The data whether HRV persistence also occurred in neonates and young infants were very limited. This prospective observational study was conducted in Niigata, Japan, between January 2020 and September 2022. The participants were hospitalized neonates and infants less than 4 months of age with fever. We excluded patients with evidence of bacterial infection or obvious sick contact with influenza or respiratory syncytial virus infection, as confirmed by rapid antigen detection tests. COVID-19 diagnosed by polymerase chain reaction (PCR) or rapid antigen detection tests were also excluded. Parechovirus and enterovirus were examined by PCR using serum and/or cerebrospinal fluid. FilmArray Respiratory Panel v1.7 was conducted on nasopharyngeal swabs. If HRV was positive, the genotype was identified. We included 72 patients (median age, 54 days; interquartile range, 28.5-79 days), and sepsis was diagnosed in 31 (43.1%) patients. In total, 27 (37.5%) patients had had positive multiplex PCR tests. These patients were more likely to have rhinorrhea ( P = 0.004), cough ( P = 0.01), and sick contact ( P < 0.001) than those who with negative multiplex PCR. HRV was the most frequently detected virus (n = 23, 85.2%), and species A (n = 15, 71.4%) and C (n = 6, 28.6%) were genotyped. No seasonality or monthly predominance of the specific HRV types was observed. HRV was an important cause of fever in neonates and young infants during the COVID-19 pandemic, 2020 to 2022.