Although present in the water column, Vibrio (V.) spp. appear at particularly high densities in association with marine bivalves, which implicates bivalves as important zoonotic agents of pathogenic Vibrio spp. Among them are serious human pathogens, such as V. parahaemolyticus and V. vulnificus. The recent emergence of new highly pathogenic V. parahaemolyticus clones and their pandemic spread raise the question for the environmental and genetic determinants leading to the emergence, proliferation, and transmission of Vibrio spp. pathotypes and for the potentially underestimated risk to the human population in Europe and worldwide. Vibrioses are commonly reported in the USA and in many Asian and South American countries; however, there is growing concern that Vibrio spp., particularly V. parahaemolyticus and V. vulnificus, may represent an important and increasing clinical problem in Europe. Since 1996, the worldwide incidence of V. parahaemolyticus infections has increased dramatically causing large-scale outbreaks in North America, Chile, India, Southeast Asia, Japan, and more recently in Spain, France and Italy.
Moreover the aquacultre producing large quantities of shrimps, mussels and other seafood is affected by Vibrio species. In terms of aquatic animals Aliivibrio salmonicida, V. tubiashii, V. anguillarum, V. splendidus and V. vulnificus have importance.