Respiratory viral infections and Kawasaki disease: A molecular epidemiological analysis.

BACKGROUND/PURPOSE: Recent large-scale epidemiological studies have revealed significant temporal associations between certain viral infections and the subsequent development of Kawasaki disease (KD). Despite these associations, definitive laboratory evidence linking acute or recent viral infections to KD cases remains elusive. The objective of this study is to employ a molecular epidemiological approach to investigate the temporal association between viral infections and the development of KD. METHODS: We analyzed 2460 patients who underwent the FilmArray® Respiratory Panel test between April 2020 and September 2021. RESULTS: Following the application of inclusion criteria, 2402 patients were categorized into KD (n = 148), respiratory tract infection (n = 1524), and control groups (n = 730). The KD group exhibited higher positive rates for respiratory syncytial virus (RSV), human rhinovirus/enterovirus (hRV/EV), parainfluenza virus (PIV) 3, and adenovirus (AdV) compared to the control group. Additionally, coinfections involving two or more viruses were significantly more prevalent in the KD group. Notably, RSV-positive, hRV/EV-positive, and PIV3-positive KD patients exhibited a one-month delay in peak occurrence compared to non-KD patients positive for corresponding viruses. In contrast, AdV-positive KD cases did not show a one-month delay in peak occurrence. Moreover, anti-RSV, anti-PIV3, and anti-AdV antibody-positive rates or antibody titers were higher in RSV-, PIV3-, and AdV-positive KD cases, respectively, compared to non-KD cases with the same viral infections. CONCLUSION: Recent infection with RSV, PIV3, or AdV, occasionally in conjunction with other viruses, may contribute to the pathogenesis of KD as infrequent complications.

Severe encephalopathy associated with SARS-CoV-2 Omicron BA.1 variant infection in a neonate.

INTRODUCTION: The coronavirus disease 2019 (COVID-19), including the Omicron variant, is less severe in children than in adults. To date, there has been no detailed description of COVID-19-associated severe encephalopathy due to the Omicron variant during the neonatal and early infantile periods. CASE PRESENTATION: During the outbreak of the Omicron variant, a 29-day-old male presented with a pale and ill appearance. The patient was intubated for mechanical ventilation owing to recurrent apnea, which subsequently turned out to be a breath-holding that may have been caused by seizure. In addition, nonconvulsive status epilepticus was observed. Total duration of repetitive seizure activities was approximately 30 min per hour when seizures were most severe. Brain magnetic resonance imaging (MRI) on day 14 revealed extensive hyperintensity in the T2 sequence, hypointensity in the fluid-attenuated inversion recovery (FLAIR) sequence in the deep and subcortical white matter, and diffusion restriction in the corpus callosum. The Omicron BA.1 variant of the severe acute respiratory syndrome coronavirus 2 was detected in his respiratory sample. Follow-up MRI on day 45 revealed multiple cystic cavitations. CONCLUSION: Although COVID-19 is not severe in most children, life-threatening conditions such as COVID-19-associated severe encephalopathy can occur during the neonatal and early infantile periods.