Molecular Epidemiology of norovirus infection among hospitalized children under 5 years with diarrhea in Lanzhou, 2015-2018

Objective To investigate the molecular epidemiological characteristics of diarrhea among hospitalized children under 5 years old in Lanzhou from 2015 to 2018. Methods The fecal specimens and related clinical information of hospitalized children with diarrhea under 5 years old in Lanzhou from January 2015 to December 2018 were collected. Amplifications were performed with RT-PCR followed by sequencing and sequence analysis. Statistical analyses were performed with SPSS 25.0 software, including chi-square test for the comparison of rates, to analyze the epidemiological characteristics of norovirus in Lanzhou from 2015 to 2018. Results The detection rate of norovirus was 14.27% (112/785), and the annual detection rates from 2015 to 2018 ranged from 7.8% to 17.6%. The differences in annual positive rates were statistically significant. Seasonal incidence peaks occurred in January, May and October, respectively. The highest and the lowest detection rates were among children of 1 years old and 2 years old, respectively, and the difference was not statistically significant. According to genotyping results, GII.4 Sydney[P31] and GII.3[P12] were the predominant genetic combinations with detection rates of 54.5% (61/112) and 36.6% (41/112), respectively. Conclusions Diversed genotypes of norovirus among children with acute gastroenteritis in Lanzhou were observed. The predominant genotypes were GII.4 Sydney[P31] and GII.3[P12]. Key words: Norovirus; Genotype; Epidemiology; Sequence analysis