Analysis on etiological and epidemiological characteristics of rash and fever syndrome in children aged ＜5 years in China, 2009−2021

Objective To understand the etiological and the epidemiological characteristics of rash and fever syndrome (RFS) in children aged ＜5 years in China, and provide evidence for the diagnosis, prevention and control of RFS.

Methods Based on the data of RFS from National Infectious Disease Surveillance Platform, the pathogens included enterovirus, measles virus, rubella virus, varicella-zoster virus, dengue virus, human parvovirus virus B19, Ebola virus, zika virus, human herpesvirus 6, Epstein-Barr virus, streptococcus group A, Salmonella typhi and Salmonella paratyphoid, borrelia-burgdorferi and rickettsia. The descriptive analysis was used to analyze the compositions of pathogens and the epidemiological characteristics of RFS in children aged ＜5 years in China from 2009 to 2021.

Results RFS in the children was mainly caused by viruses, which included enterovirus (85.78%) , measles virus (10.03%) and varicella-zoster virus (1.45%), causing 97.26% of the total RFS cases. The cases caused by rubella virus and other pathogens increased from 2018 to 2021. The predominant enterovirus serotypes shifted from EV-A71 and CV-A16 to CV-A6 and CV-A10 during 2009−2021. The highest detection rate of RFS was reported in age group 1−2 years (70.53%) (χ²=292.336, P<0.001) and the detection rate was higher in southern China (71.12%) than in northern China (65.35%) (χ²=305.946, P<0.001). The positive rate of enterovirus was higher in age group 1−2 years and in southern China. The positive rate of measles virus was higher in age group <1 years in northern China. The positive rate of varicella-zoster virus was higher in northern China. The positive rate in spring and summer was higher than that in autumn and winter (χ²=295.060, P<0.001). The positive rate of enterovirus increased in summer and autumn, while the positive rate of measles virus increased in winter and spring, and the positive rate of varicella-zoster virus was highest in winter. The seasonal distribution detection peaks of the three viruses were different in the south and north regions.

Conclusion Viruses, especially enterovirus, measles virus, and varicella-zoster virus infections, were the main pathogens causing RFS in children under 5 years old in China from 2009 to 2021, diversify was observed in pathogens causing RFS and the predominant enterovirus serotypes shifted, suggesting that it is necessary to further strengthen the surveillance for the etiological characteristics of RFS.