Clinical characteristics of Kawasaki disease and concurrent pathogens during isolation in COVID-19 pandemic

Background The aim of this study is to explore the characteristics of Kawasaki disease(KD)and concurrent pathogens due to a stay-at-home isolation policy during coronavirus disease 2019(COVID-19)epidemic.Methods All patients with KD admitted between February and April in 2015-2020,were classified into before(group 1,in 2015-2019)and after(group 2,in 2020)isolation groups.A total of 4742 patients[with KD(m=98)and non-KD(n=4644)]referred to Mycoplasma pneumoniae(MP)and virus detection were analyzed in 2020.Clinical characteristics,laboratory data,and 13 pathogens were analyzed retrospectively.Results Group 2 had a significantly increased incidence of KD(0.11%)with 107 patients compared to that of group 1(0.03%)with 493 patients.The comparisons of oral mucosal change,strawberry tongue,desquamation of the fingertips,cervical lymphadenopathy and neutrophil percentage decreased in group 2 compared to group 1.The infection rate of MP increased significantly in group 2(34.7%)compared to group 1(19.3%),while the positive rate of viruses decreased significantly in group 2(5.3%)compared to group 1(14.3%).In 2020,the positive rate of MP infection increased significantly in patients with KD compared to the increase in patients with non-KD.The infection rate of MP for younger children aged less than 3 years old was higher in group 2 than in group 1.Conclusion Compared with the characteristics of KD from 2015 to 2019 years,the incidence of KD was increased in 2020 and was accompanied by a high incidence of MP infection,especially in younger children(less than 3 years old)during the isolation due to COVID-19 pandemic.