[Norovirus infection surveillance in early warning of outbreaks in population in oyster farming areas].

OBJECTIVE: To have an insight into the prevalence tendency caused by Noroviruses( NoVs) in population of oyster farming areas, and evaluate the early warning signification of acute gastroenteritis( AGE) monitoring. METHODS: Between January and December in 2014, a retrospective household survey of AGE during past four weeks was conducted to residents using multi-stage sampling in oyster farming areas. Norovirus capsid genome was detected using real-time RT-PCR and semi-nested PCR, sequenced and phylogenetic analyzed. RESULTS: A total of 75 cases of AGE were reported. The incidence rate was 0. 10 per person-year, the detection rate of norovirus was 20. 0%( 15 /75). The dominant epidemic No Vs strain in oyster farming was still GII. 4 Sydney 2012. Furthermore, a newly GII. 17 variant was detected and early in March 2014. CONCLUSION: The GII. 4 Sydney 2012 genotype is still prevalent strain that caused AGE currently in the community residents of oyster farming areas. NoVs GII. 17 variant was found in sporadic patients of sentinel hospital AGE monitoring in March 2014 that have an early warning effect to the outbreaks of winter in 2014.

Detection and molecular characterization of emergent GII.P17/GII.17 Norovirus in Brazil, 2015.

A newly GII.17 Kawazaki_2014 variant strain was detected recently in Brazil. Phylogenetic analysis reveals at least four independent introduction events of this lineage into this country that took place throughout 2014, coinciding with FIFA World Cup in Brazil, 2014, and Hong Kong has been identified as the most likely source of introduction. This variant emerged in Asia causing outbreaks and replacing prevalent GII.4. Emergence of GII.P17/GII.17 variant emphasizes the need for active laboratory surveillance for NoV including molecular epidemiology and studies on virus evolution.