Original Article
A molecular epidemiological survey on the outbreak of recombinant Norovirus GII.P16-GII.2 in Guangzhou city
Wenzhe Su, Jinmei Geng, Sailin Lai, Jingwen Liu, Hui Wang, Chun Chen, Dahu Wang, Biao Di, Zhoubin Zhang, Huaping Xie
Published 2019-08-30
Cite as Chinese J Exp Clin Virol, 2019, 33(4): 362-368. DOI: 10.3760/cma.j.issn.1003-9279.2019.04.006
Abstract
ObjectiveTo find out the source and the epidemic pattern of norovirus outbreak in July, 2016 to June, 2017 in Guangzhou.
MethodsThe stool samples and clinical information of diarrhea cases were collected by the sentinel hospitals and CDCs; a real-time RT-PCR method was used to detect the norovirus nucleic acids from the samples, the positive ones were amplified and sequenced; the partial sequences of norovirus were aligned by an online BLAST alignment, and a phylogenetic tree was constructed by a neighbor-joining method .
ResultsA total of 854 cases with infectious diarrhea were reported by Guangzhou diarrhea surveillance network from July, 2016 to June, 2017; the gender ratio (male versus female) was 1∶0.67; 78.33% of the cases were preschool children under the age of 7 years. Totally 220 samples were detected norovirus G II+ (25.76%, including 5 double-positive samples with G I+ ). GII.Pe-GII.4.Sydney_2012 was the prevalent genotype in the second half of 2016 (94.64%), which was replaced by GII.P16-GII.2 in the first half of 2017 (67.65%). Since September 2016, the reported number of norovirus-caused diarrhea epidemic was increased gradually; the peak of epidemic curve emerged in February to March of 2017, and the number started to decrease since April. In May to June there were only 2-3 epidemics reported monthly. All the endemics from September to November 2016 were caused by genotype GII.Pe-GII.4.Sydney_2012; the endemics from December 2016 to April 2017 were mainly caused by genotype GII.P16-GII.2. Some samples from kitchen workers and babysitters were detected GII+ , which was consistent with the result of the cases′ samples.
ConclusionsIt was the first time that the novel GII.P16-GII.2 recombinant strain outbroke occurred in Guangzhou City and homology analysis also suggested that GII.P16-GII.2 was the main source of those epidemics in 2016 -2017 winter and spring season. Furthermore, The kitchen workers and babysitters may have played an important role in the spread of norovirus.
Key words:
Norovirus; Infectious diarrhea; Molecular genotyping; Molecular epidemiology
Contributor Information
Wenzhe Su
Department of Virology and Immunology, Guangzhou Center for Disease Control and Prevention, Guangzhou 510440, China
Jinmei Geng
Department of Virology and Immunology, Guangzhou Center for Disease Control and Prevention, Guangzhou 510440, China
Sailin Lai
Department of Virology and Immunology, Guangzhou Center for Disease Control and Prevention, Guangzhou 510440, China
Jingwen Liu
Department of Virology and Immunology, Guangzhou Center for Disease Control and Prevention, Guangzhou 510440, China
Hui Wang
Department of Infectious Disease Control and Prevention, Guangzhou Center for Disease Control and Prevention, Guangzhou 510440, China
Chun Chen
Department of Infectious Disease Control and Prevention, Guangzhou Center for Disease Control and Prevention, Guangzhou 510440, China
Dahu Wang
Department of Infectious Disease Control and Prevention, Guangzhou Center for Disease Control and Prevention, Guangzhou 510440, China
Biao Di
Department of Virology and Immunology, Guangzhou Center for Disease Control and Prevention, Guangzhou 510440, China
Zhoubin Zhang
Directors′ Office, Guangzhou Center for Disease Control and Prevention, Guangzhou 510440, China
Huaping Xie
Department of Virology and Immunology, Guangzhou Center for Disease Control and Prevention, Guangzhou 510440, China
