Detection and Complete Genome Sequence analysis of Human Adenovirus in Children with Acute Diarrhea in Yunnan, China, 2015–2021

Abstract Aims: This study aimed to determine the distribution and prevalence of gastroenteritis with HAdV in children in Yunnan province, China, 2015-2021, and also contribute for adopting preventive measures to reduce morbidity and mortality in children. Background: Human adenovirus (HAdV) is considered as a significant enteropathogen associated with diarrhea in children. However, limited data are available regarding the epidemiology and genetic diversity of HAdV in children with diarrhea in Yunnan province, China. Methods: A total of 1754 fecal samples were subjected to Real-time RT-PCR to detect HAdV, the positive samples underwent further Next-generation sequencing, and epidemiological data were analyzed as well. Results: 1754 patients with diarrhea were enrolled, among them1041 were male and 713 were female, The M:F rate was1.46. Overall, 72/1754 stool samples (4.10%) were positive for HAdV. The detection rates of all age groups varied from 2.50% to 4.78%. From 2015-2021, the annual detection rate was between 1.62% and12.26%. The frequency of HAdV was the highest in the age group >1to≤2 years, HAdV infection occurred all year around, The highest HAdV detecting rate was 15.69%(16/102) in June, Followed by November 8.19%(14/171). Of the 72 HAdV-positive samples, 13 HAdV strains whole genome were successfully sequenced, 76.92%(10/13) were classified as HAdV-F41, and 23.08% (3/13) were classified as HAdV-C2. HAdV-F41 was the predominant HAdV genotype in children with acute diarrhea. Conclusions: Children at all ages are susceptible to HAdV. Marked variation in yearly prevalence has been demonstrated. However, the information we collected are too limited to elucidate their epidemiological role as there are no systematic surveillance and clinical studies on HAdVs in Yunnan. the true epidemiology of HAdV remains incompletely understood. In order to fully understand the prevalence of HAdV, it is imperative to establish a HAdV virological surveillance system to collect relevant clinical, epidemiological data as soon as possible to assess the potential risk of HAdV among children. and develop effective vaccines at preventing HAdV diarrhea is warranted.