Skip to main content
SLU publication database (SLUpub)

Research article2011Peer reviewedOpen access

Scientific Opinion on Epizootic Ulcerative Syndrome

Bötner, Anette; Broom, Donald; Doherr, M; Domingo, Mariano; Hartung, Jörg; Keeling, Linda; Koenen, Frank; More, Simon; Morton, David; Oltenacu, Pascal; Salati, Fulvio; Salman, M; Sanaa, M.; Sharp, James M; Stegemann, Jan A; Szücs, Endre; Thulke, Hans H; Vannier, Philippe; Webster, John; Wierup, Martin


The AHAW panel conducted an assessment of the risk of entry, release, spread and possible impact of epizootic ulcerative syndrome (EUS) in Europe. The risk of entry is linked to the probability of infection in the source region and the frequency of imports. A greater risk of entry was associated with the importation of ornamental fish into closed ornamental facilities (COF). COF, as defined by EU legislation, are pet shops, garden centres, garden ponds, commercial aquaria or wholesalers keeping ornamental aquatic animals without any direct contact with natural waters; or equipped with an effluent treatment system. The release of pathogens from COF could occur through the sale of live fish to hobbyists, insufficient effluent treatment or unintentional contact with natural waters. Assuming regular entry and release the long-term lack of reporting of EUS is a apparent contradiction. The following scenarios could explain it: i) Fish in European waters have never been exposed to the pathogen because the survival of released zoospores is too short, ii) EUS does not establish, but the pathogen fades out after entry into the EU, due to unfavourable conditions, iii) Ecological or epidemiological circumstances are not favourable for disease expression, iv) EUS is endemic and regularly misdiagnosed. The insufficient data from monitoring of aquaculture fish or wild stocks in Europe preclude confirmation or estimation of the likelihoods of these scenarios. The impact of EUS on EU aquaculture, would range from no impact, if there was no spread, to low impact if there was spread without disease, low incidence or weak disease patterns. However, if endemic the impact may change in the future if conditions such as climate, water quality or availability of susceptible species, either in aquaculture or in natural water bodies, become favourable for initiating epidemics and disease expression.

Published in

EFSA Journal
2011, Volume: 9, number: 10, pages: 2387