Insight on parasite transmission among fish
Enteromyxum leei (E. leei) is a critical pathogen of Sparus aurata and other fish cultured in the Mediterranean and is responsible for the disease myxidiosis. This is because it causes high mortalities both in netpens and in land-based mariculture systems, with subsequent economical impact. Although myxidiosis is highly relevant, there are major limitations regarding the knowledge of the parasite's life cycle, transmission, epidemiology, mechanisms of infection and immunology. In light of this, the MYXFISHCONTROL project examined the transmission of E. leei through the routes of cohabitation (CH), oral (OR) and contaminated effluent (EF). Some factors taken into consideration were parasite availability, entry route, differences in fish susceptibility and temperature. As it turns out, parasite stages were located in the different areas of the intestinal tract. Other parts of the digestive system such as the stomach and gall bladder as well as in the haematopoietic organs, liver and blood were never found to be infected. Parasites were found primarily in small patches, in which initial stages were usually located in the periphery and more mature stages in the central area.
