Hydrodynamic connectivity, water temperature, and salinity are major drivers of piscirickettsiosis prevalence and transmission among salmonid farms in Chile
Piscirickettsiosis is one of the most important chronic and acute diseases affecting farmed salmonids. A stochastic hydrodynamic connectivity-based disease model was used to determine how hydrodynamic connectivity among farms, seawater temperature, and salinity modulate piscirickettsiosis risk dynamics. Bravo et al. show that these factors play a major role in disease prevalence, e.g. in farms downstream from infected farms, observed disease prevalence 25 weeks into the farming cycle was close to 100%, while in farms with little or no exposure to upstream, infected farms, prevalence reached only ~10% by the end of the farming cycle (Week 56). This knowledge and the use of modelling tools can allow industry and regulators to develop effective and targeted disease control strategies.