Yersiniosis: Investigation of increasing frequency in Norwegian sea-farmed salmon

The project will focus on identification of the cause(s) behind the recent increase in number of yersiniosis outbreaks in mid-Norway.

Yersiniosis, caused by the bacterium Yersinia ruckeri is a disease exclusively found in salmon in Norway. Yersiniosis, which although considered an essentially freshwater disease, has been more frequently diagnosed in sea-farmed salmon in recent years, particularly in mid-Norway. Introduction of intraperitoneal vaccination has reduced the numbers of outbreaks, but we hope that increased knowledge of the bacterium, transmission pathways and infection dynamics may, in the longer term, make vaccination unnecessary. The project will therefore focus on identification of the cause(s) behind the recent increase in number of yersiniosis outbreaks in mid-Norway.