Outbreaks of noroviral gastroenteritis and their molecular characteristics in China, 2006 -2007 / 中华流行病学杂志

ABSTRACT

Objective To acknowledge the epidemiology of gastroenteritis outbreaks caused by norobiruses and their genotypes. Methods Epidemiologic data and specimens were collected from 19 gastroenteritis outbreaks. 201 specimens were detected for norovirus, rotavirus, astrovirus,adenovirus and sapovirus by RT-PCR methods and PCR products were sequenced. Sequence alignment and phylogenetic analysis were performed by Clustal X 1.83 and MEGA 4.0 programs.Results Noroviruses were one of the most predominant pathogens causing viral gastroenteritis outbreaks ( 12 of 19 outbreaks, accounting for 63.2% ). Variant G Ⅱ -4/2006b was the predominant strain responsible for 11 of the 12 NV-associated outbreaks. Other genotypes would include G Ⅱ -17,G Ⅱ -6 and G Ⅱ -3. The NV-associated gastrocnteritis outbreaks occurred mainly in winter and spring between December 2006 and April 2007. These gastroenteritis outbreaks caused by noroviruses would involve all age groups in various locations. Meantime, 2 out of 12 outbreaks were caused by norovirus or other viruses. In addition, multiple viruses and multiple genotypes of noroviruses were found in the same outbreak. Conclusion Noroviruses were one of the most major pathogens causing gastroenteritis outbreaks while G Ⅱ -4/2006b variant was identified as the predominant strain in China.