Molecular epidemiology of pediatric Norovirus GⅡ infection in Tianjin,2018 / 中华检验医学杂志

ABSTRACT

Objective:To analyze the molecular epidemiological characteristics of GⅡNorovirus (NoV) infection in children in Tianjin Children′s Hospital in 2018.Methods:Single center study. From January to December 2018, a total of 2 185 stool specimens were collected from the children with acute gastroenteritis suspected caused by virus infection in Tianjin Children′s Hospital. Norovirus was detected by real-time fluorescence reverse transcription polymerase chain reaction (RT-PCR).The capsid protein VP1(VP1) region of positive samples was amplified and sequenced. The phylogenetic tree was constructed by MEGA5.05 for analyzing the results. The detection of NoV in different age groups and different months were compared by SPSS 20.0.Results:Among the 2 185 stool specimens,610 were NoV positive, the positive rate was 27.9% (610/2 185).All of the positive samples were GⅡgenogroup. Seven genotypes were found, with GⅡ.3 subtype accounting for 46.2%(151/327),GⅡ.4 subtype accounting for 40.1%(131/327),GⅡ.2 subtype accounting for 4.6%(15/327), other subtypes accounting for 9.1%(30/327).There was a significant difference in NoV detection rate among different age groups (χ 2=17.050, P=0.002). Among the positive specimens, the detection rate of less than or equal to 3 years old was the highest which is accounting for 89.2%.Also there was a significant difference in NoV detection rate among different months(χ 2=225.153, P<0.001).November and December are the most frequent months. There was significant difference between GⅡ.3 and GⅡ.4 NoV infection in children with granulocytopenia (χ 2=11.270, P=0.001) , and also in children with respiratory symptoms (χ 2=7.257, P=0.007) . Conclusions:GⅡ.3 and GⅡ.4 were the main genotypes of NoV infection in children in Tianjin in 2018. The Multiple genotypes suggests that the monitoring and prevention of NoV infection in children should continue to be strengthened in the future.