[Molecular epidemiology of norovirus in children with acute gastroenteritis in Tianjin, China].

OBJECTIVE

To investigate the molecular epidemiological characteristics of norovirus (NoV) among children with acute gastroenteritis in Tianjin in 2017.

METHODS

A total of 758 stool specimens were collected from the children with acute gastroenteritis possibly caused by viral infection in Tianjin Children's Hospital between January and December, 2017. Quantitative real-time RT-PCR was used for primary screening of NoV, and conventional RT-PCR was used for gene amplification, sequencing and genotype identification of the VP1 region of capsid protein in positive specimens.

RESULTS

Among the 758 specimens, 241 (31.8%) were found to have GII NoV. Sequencing of the VP1 region of capsid protein in positive specimens showed that among the 241 specimens with GII NoV, 69 (28.6%) had GII.4 subtype, 51 (21.2%) had GII.3 subtype, 24 (10.0%) had GII.2 subtype, and 18 (7.5%) had other subtypes. There was a significant difference in NoV detection rate between different age groups (P=0.018), and the 1- <4 years group had the highest NoV detection rate (37.3%). There was also a significant difference in NoV detection rate across seasons (P<0.001), and there was a highest NoV detection rate in winter (48.1%). Twenty-seven children (3.6%) had co-infections with NoV and rotavirus.

CONCLUSIONS

NoV is one of the major pathogens of the children with acute gastroenteritis from Tianjin in 2017. GII genotype, especially GII.4 subtype, is the prevalent strain. NoV infection is commonly seen in children less than 4 years and reaches the peak in winter. Some children are found to have co-infections with rotavirus.