THE ROLE OF LIVE FISH TRADE IN THE WIDESPREAD OF PARASITES

The transmission of infections from an infected to an uninfected area due to the movement of fish is a problem of major concern for fish farms, for wild fish, and for public health.  During a fish health monitoring performed in July 2017 in a northwest Italian trout farm, an infection of  C. farionis was first recorded in that area . This report highlights the contribution of live fish trade  in the introduction of parasites in a new territory.

Ictiofauna translocation are commonly used to replenish and enhance the fish population in inland waters. However, the movement of fish represent a potential risk of introducing new pathogens. The aim of this study was to report the presence of C. farionis in a new area in order to highlight the role of live fish trade in the diffusion of parasites. To better understand the presence of C. farionis in Italy, a parasitological survey was carried out in a rainbow trout farm located in Northwest.

The most probable explanation of the presence of  C. farionis was due to the movement of a fish batch from an infected area. Therefore, the examined fish came from northeast Italy. T his area is previously described as an endemic area for  C. farionis .

Fish populations reflect susceptible infections of their environment . However, majority of fish in a population may show no evidence disease .

Therefore, there is a high risk that some individuals  can harbor a subclinical infection.

The establishment of a new parasite depend on the interaction between wild host species and the infected imported animals. The design of most aquaculture systems promotes the interaction between farmed and wild aquatic animal populations, creating a risk for endemic species. It is also noted  that the introduction of new parasites could also affect productivity and quality of fish products becoming a potential health risk for national aquaculture. The risks associated with the widespread of infectious diseases are underestimated and have been poorly studied especially for parasite infections. European legislations cover primary attention mostly on viral disease, contributing to the spread of  parasite infections and bacterial diseases.  Prevention the spread of animal disease by international trade of animals is one of the  main  aims of the World Organization for Animal Health (OIE).  Further studies are needed to control parasitic species affecting aquaculture production and assess the efficacy of current strategies.