ARS | Publication request: Emerging problems with zoonotic bacteria in intensive warm water fish culture: facts and risks

Submitted to: European Association of Fish Pathologists
Publication Type: Abstract Only
Publication Acceptance Date: April 24, 2009
Publication Date: September 14, 2009
Citation: Haenen, O., Roozenburg-Hengst, I., Engelsma, M., Evans, J.J. 2009. Emerging problems with zoonotic bacteria in intensive warm water fish culture: facts and risks. 14th European Association of Fish Pathologists. International Conference Prague, Czech Republic September 14-19, 2009. p. 453.

Technical Abstract: With the development of warm water aquaculture in intensive indoor recirculation systems in Europe and the United States new bacterial disease problems occur, especially in the cultured fish, and in humans. These so called zoonotic bacteria are more frequently isolated from severe disease outbreaks with high mortalities in fish, cultured at water temperatures of 24-28°C. In The Netherlands, in the last decennia several cases of Vibrio vulnificus, Edwardsiella tarda, Streptococcus agalactiae and Mycobacterium marinum a.o. have been diagnosed in eels, African catfish, tilapia, and barramundi, a.o., some of which were related to mild to more severe disease in the fish culturist or fish processor after contact of the infected fish with injured skin (hand or finger). Most zoonotic infections were related to Vibrio vulnificus and Mycobacterium marinum. During an investigation of the presence of zoonotic bacteria (Edwardsiella tarda, Vibrio vulnificus, Streptococcus iniae, Streptococcus agalactiae and Mycobacterium spp.) in healthy looking eels, African catfish and tilapia from Dutch warm water fish farms in 2008, 1 of 8 African catfish farms was found positive for Streptococcus agalactiae, 1 of 8 for Edwardsiella tarda, 3 of 7 tilapia portions were found positive for Mycobacterium fortuitum, and none of 6 eel farms were found positive for any of these bacteria. Moreover, in interviews with the consulted fish farmers and fish processors, most of them indicated they get regularly injuries from fin spines and from knifes at fish slaughter, after which various inflammations of the fingers or hand may result. As hospitals culture bacteria at >37°C only, a diagnosis of fish tuberculosis may be missed. In this presentation, an overview of the fish clinical cases with the contact- zoonotic bacteria is given, with examples of zoonosis in humans. The consequences of the recent findings are discussed, both in fish culture, veterinary, as in human health perspective, and recommendations for prevention will be proposed.