Epidemiological Characteristics Of Norovirus In Suzhou,2011-2013

Objective:To analyze the epidemiological characteristics of norovirus infection in Suzhou during 2011 and 2013.Method:1.During 2011 and 2013,1214 diarrhea samples were collected from hospitalized children cases with acute viral diarrhea in the Children's Hospital of Suzhou University.The clinic data and laboratory measurement were recored.2.The diarrhea samples were amplified by the conventional RT-PCR method to detect the capsid region of NV.All the positive products were sequenced and analyzed.Result:1.Epidemiological trend of norovirus in Suzhou from 2011 to 2013(1)The positive rate of norovirus was significantly decreased from 2011 to 2013.(2)The positive rate of norovirus in Suzhou was the highest in autumn and the lowest in summer.(3)Compared to other regions,the positive rate of norovirus was significantly decreased in Yuanqu from 2011 to 2013.(4)The positive rate at the age group of 7-12 month was higher than other groups.The positive rate in the male was 24.09%,while the positive rate in the female was 20.59%.2.Molecular epidemiological trend of norovirus in Suzhou from 2011 to 2013(1)184 strains were successfully sequenced.One strain belonged to GII.4 95/96 US,76 strains belonged to GII.4/2006 b,14 strains belonged to GII.4/New Orleans,27 strains belonged to GII.4/Sydney,1 strain belonged to GII.2,62 strains belonged to GII.3,2 strains belonged to GII.6,and 1 strain belonged to GII.7.(2)GII.4 was detected only less than 36 month of age group,GII.4/2006 B is mainly detected in 7-12 months group,GII.4/Sydney was mainly detected in 13-24 months group.Conclusion:1.The positive rate of norovirus was significantly decreased from 2011 to 2013.2.GII.4/Sydney has replaced GII.4/2006 b as a prevalent strain in Suzhou and its surrounding areas.