[Pathogenic diagnosis of an unexplained epidemic event of infectious diarrhea].

Objective: To determine the pathogen of an unexplained epidemic event of infectious diarrhea by laboratory diagnosis of suspected cases samples.

Methods: 28 samples from 28 suspected cases (22 fecal samples, 3 vomitus samples, 3 anus swab samples) were tested for Norovirus by RT-PCR. Sequencing and phylogenetic analysis were acomplished of 5 positive samples.

Results: 160 of 5694 population were ill with an attack rate of 2.81%. The peak period was 7-9, March. 14 of 28 samples were tested Norovirus positive.Sequencing and phylogenetic analysis showed Norovirus type GII/4 was the causative agent and it had highest identity (97. 9%) with epidemic strain 2006b.

Conclusion: The epidemic event ofinfectious diarrhea were caused by GII/4 Norovirus strains.