Epidemiology of Acute Infectious Diarrhea-Associated Viruses in Children in Hangzhou, China, 2023

Objective To investigate the epidemiological characteristics of children infected with diarrheal virus in Hangzhou, China, 2023. Methods From January 2023 to December 2023, 20,939 stool samples from children with acute infectious diarrhea were collected for the detection of rotavirus A and human adenovirus (HAdV), using latex agglutination detection kits; 7,584 stool samples were collected for the detection of norovirus, using real-time polymerase chain reaction reagent. Results A total of 639 (3.0%, 639/20,939) tested positive for rotavirus A, and 1,201 (5.7%, 1,201/20,939) positive samples were detected by colloidal gold method. The positive rates of norovirus were 42.2% (3,203/7,585). Among all age groups, the rotavirus A positive detection rate was the highest in participants aged 3 to 6 years (6.46%, 260/4,024). The monthly distribution of patients with rotavirus A showed that the number of cases was the lowest in October (0.45%, 8/1,779) and reached the peak in April (7.97%, 144/1,806). The highest and lowest positive rates among all age groups for HAdV were found in children aged 3 to 6 years(8.27%, 333/4,024) and in those aged 0 to 6 months (2.21%, 60/2,717). The monthly positivity rates of HAdV spanning from January to November 2023 were 1.38, 1.44, 2.34, 3.65, 6.64, 7.71, 7.54, 7.13, 6.82, 4.15, and 6.50%, and reached the peak in December (8.17%). For norovirus, children aged 1 to 3 years had the highest positive detection rate (57.95%, 1,349/2,328), while infants aged 0 to 6 months had the lowest positive detection rate (19.60%, 205/1,046). The results show that January had the lowest number of cases (14.63%, 6/41), while September had the highest (50.51%, 545/1,079). Conclusion The detection rate of rotavirus A and HAdV was highest among participants aged 3 to 6 years, whereas the detection rate of norovirus was highest among those aged 1 to 3 years. The monthly distribution peaks for the three enteric viruses varied significantly.