Tracking the transmission routes of genogroup II noroviruses in suspected food-borne or environmental outbreaks of gastroenteritis through sequence analysis of the P2 domain.
ABSTRACT The aim of this study was to apply sequence analysis of a hyper variable region of the norovirus (NoV) genome in order to identify point source outbreaks associated with suspect food or water. The hyper-variable region of the gene encoding the P2 domain was chosen as small differences in sequence are likely to indicate virus from different sources whereas identical sequence may reveal transmission routes and the source of contamination. Strains with 100% similarity were considered as originating from a common source, whereas, strains with one or more mutations in the hyper variable region sequenced were regarded as representing unrelated transmission events. This study was able to identify a point source outbreak of a dominant strain, GII-4, on a cruise ship but also of a less common strain, GII-2, between two schools. Also identical GII-3 strains were demonstrated in food handlers amongst the same outbreak; however epidemiologically related outbreaks showed different GII-3 strains indicating multiple sources of contamination.
Article: Comprehensive analysis of a norovirus-associated gastroenteritis outbreak, from the environment to the consumer.[show abstract] [hide abstract]
ABSTRACT: Noroviruses have been recognized to be the predominant agents of nonbacterial gastroenteritis outbreaks in humans, and their transmission via contaminated shellfish consumption has been demonstrated. Norovirus laboratory experiments, volunteer challenge studies, and community gastroenteritis outbreak investigations have identified human genetic susceptibility factors related to histo-blood group antigen expression. Following a banquet in Brittany, France, in February 2008, gastroenteritis cases were linked to oyster consumption. This study identified an association of the norovirus illnesses with histo-blood group expression, and oyster contamination with norovirus was confirmed by qualitative and quantitative analyses. The secretor phenotype was associated with illness, especially for the non-A subgroup. The study showed that, in addition to accidental climatic events that may lead to oyster contamination, illegal shellfish collection and trading are also risk factors associated with outbreaks.Journal of clinical microbiology 03/2010; 48(3):915-20. · 4.16 Impact Factor