Cross-sectional study on norovirus genotyping and epidemiology among hospitalised children with acute gastroenteritis in Tianjin, North China, 2020-2023.

PURPOSE: To understand the molecular epidemiological and clinical characteristics of norovirus in children with acute gastroenteritis in Tianjin from 2020 to 2023.

METHODS

A total of 6714 faecal samples were collected from children aged 0–17 years with acute gastroenteritis who visited Tianjin Children’s Hospital from August 2020 to July 2023. All samples were initially screened for norovirus using reverse transcription PCR. The polymerase region and capsid protein region of the initially screened positive samples were amplified using reverse transcription PCR, the sequences were aligned and a phylogenetic tree was constructed.

RESULTS

Of the 6714 children with acute gastroenteritis, 1395 (20.78%) tested positive for norovirus in stool samples. Among them, 810 were male (20.62%, 810/3929) and 585 were female (21.01%, 585/2785). Norovirus detection rate showed seasonal differences, with the detection rates of norovirus-RNA in spring, summer, autumn and winter being 27.97% (605/2163), 11.04% (195/1767), 12.04% (141/1171) and 28.15% (454/1613), respectively. 155 norovirus-positive specimens were subjected to dual-region typing and clinical symptom-related information was collected. They were divided into nine genotypes, all of which were GII type. The three most prevalent genotypes were GII.4(P16), GII.3(P12) and GII.2(P16). The GII.4(P16) genotype accounted for 38.06% (59/155), the GII.3(P12) genotype for 27.74% (43/155) and the GII.2(P16) genotype for 19.35% (30/155).

CONCLUSION

From 2020 to 2023, the main age of onset of diarrhoea in children in Tianjin was 13–36 months, with a higher incidence in spring and winter. The most susceptible genotypes were GII.4(P16), GII.3(P12) and GII.2(P16). Abdominalgia, aminotransferase, C-reactive protein, procalcitonin and neutrophil count are statistically associated with norovirus genotypes in paediatric patients. Close monitoring of the norovirus’s spread in the population is crucial to prevent outbreaks in childcare facilities, schools and other places where children congregate, which could increase the risk of severe cases, burden family care and strain public health control efforts.