Risk factors for infectious pancreatic necrosis in farmed Chilean Atlantic salmon (Salmo salar L.) from 2010 to 2013

• Published in: Preventive veterinary medicine 2019-06, Vol.167, p.182-189
• Main Authors: Escobar-Dodero, J., Kinsley, A., Perez, A.M., Ibarra, R., Tello, A., Monti, G., Mardones, F.O.
• Format: Article
• Language: English
• Subjects: Animals; Atlantic salmon farming; Birnaviridae Infections - epidemiology; Birnaviridae Infections - veterinary; Birnaviridae Infections - virology; Chile - epidemiology; Cohort Studies; Disease management; Infectious pancreatic necrosis virus; IPN; Retrospective Studies; Risk Factors; Salmo salar
• ISSN: 0167-5877; 1873-1716
• DOI: 10.1016/j.prevetmed.2018.04.016

Infectious pancreatic necrosis (IPN) is a widespread and economically devastating fish disease caused by infection with a virus referred to as IPN virus (IPNv). In Chile, the disease is endemic and prevalent in both fresh- and salt-water farms affecting cultured salmonids, mainly Atlantic salmon. Here, we present the results of a retrospective cohort study of Atlantic salmon farms stocked between 2010 and 2013, aimed at quantifying the extent to which certain epidemiological factors influence the time interval between stocking and onset of IPN mortality (time to mortality, ttm) in marine farms. Six variables were retained in a final multivariable Cox proportional hazard model. Compared to the 2010 stocking year, ttm was shorter for salmon stocked in years 2012 (HR = 2.1; p = 0.005) and 2013 (HR = 4.3; p = 0.01). The number of salmon farms within a 10-km radius (HR = 1.07; p = 0.002), positive report of IPN in the previous production cycle (HR = 1.95; p = 0.006), three or more smolt batches (HR = 2.27; p