Infection status and genetic diversity of noroviruses in patients with acute gastroenteritis in Huzhou, Zhejiang,2014

Objective To understand the infection status of norovirus in patients with acute gastroenteritis in Huzhou, Zhejiang province, in 2014, and the genetic characteristics of norovirus isolated from the patients. Methods A total of 797 stool samples were collected from outpatients with acute gastroenteritis in 2 hospitals in Huzhou from January to December 2014. Real-time RT-PCR was performed to detect norovirus nucleic acid, the positive samples were used for the sequencing of capsid protein of norovirus. Results Among the 797 stool samples, 149 were norovirus positive (18.70%), and norovirus GⅡ was predominant, accounting for 89.26% (134/149). At least 12 genotypes were identified among GⅠ and GⅡ isolates, including GⅠ.1, GⅠ.2, GⅠ.5, GⅠ.6, GⅠ.7, GⅡ.2, GⅡ.3, GⅡ.4, GⅡ.6,GⅡ.8, GⅡ.17 and GⅡ.21. GⅡ.4 Sydney_2012 (55.5%) was the most frequently detected genotype, followed by GⅡ.17 (25.5%). Conclusion Our findings suggested that norovirus was the common causative agent of acute gastroenteritis in Huzhou during the study period, the genetic characteristics of the norovirus circulating in Huzhou were complex. Except predominant GⅡ.4 Sydney_2012, the infection caused by GⅡ.17 strains occurred in late 2014, suggesting the importance of strengthened surveillance for diarrhea caused by norovirus in Huzhou for the future epidemic prevention and control.