Risk factors associated with Enteromyxum scophthalmi (Myxozoa) infection in cultured turbot, Scophthalmus maximus (L.)

• Published in: Parasitology
• Main Authors: Quiroga, María Isabel, Redondo, Mª José, Sitjà-Bobadilla, Ariadna, Palenzuela, Oswaldo, Riaza, Ana, Macías, M. A., Vázquez, Sonia, Nieto, José M., Álvarez-Pellitero, Mª del Pilar
• Other Authors: European Commission, Ministerio de Ciencia y Tecnología (España), Stolt Sea Farm
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Cambridge University Press 2006
• Subjects: Aquaculture; Enteromyxosis; Epidemiology; Fish; Myxosporea; Scophthalmus maximus; Turbot
• Online Access: http://hdl.handle.net/10261/253730; https://doi.org/10.1017/S0031182006000515; https://doi.org/10.13039/501100000780; https://doi.org/10.13039/501100006280

An epidemiological cohort study of Enteromyxum scophthalmi in cultured turbot was performed on a farm in North Western Spain. Four different ongrowing stocks (A, B, C, D) were monitored monthly until market size. Fish from stocks C and D were divided into 2 subgroups, receiving filtered (CF and DF) or unfiltered (CUF and DUF) water. The lack of water filtration was positively associated with infection prevalence, as all fish kept in filtered water remained uninfected. Parasite abundance varied seasonally (P<0·05) in stock B and subgroup CUF. Infection was also associated (P<0·05) with host weight, and the highest prevalences and intensities were detected in 101-200 g and 201-300 g fish. Distribution pattern of E. scophthalmi in subgroups CUF and DUF had a variance higher than the mean, indicating overdispersion. The minimum period necessary for the first detection of the parasite and for the appearance of disease symptoms and mortality, varied depending on the stock and introduction date, although a long pre-patent period was always observed. Several factors, such as host density, parasite recruitment and parasite-induced fish mortality can contribute to the observed distribution pattern. Risk factors found to be associated with E. scophthalmi infection, including water quality and accumulation of infective stages in the culture tanks, should be considered when designing control strategies to prevent the introduction and spread of infective stages in the facilities. © 2006 Cambridge University Press. Funding for this study was provided by the EU and the Spanish Ministerio de Ciencia y Tecnología through research grants FEDER 1FD97-0679-C02-01 and AGL2001-2241-C02-01. Additional support was obtained from Stolt Sea Farm S. A. We are grateful to J. Monfort from IATS and C. M. Carreira from the School of Veterinary Medicine of Lugo for histological processing.