Co-infections and multiple infections are extremely common in aquatic environments and therefore, in aquaculture production. Co-infections and multiple infections are defined as infectious diseases caused by two or more different pathogens either simultaneously or as secondary infections, thus two or more infectious agents are active together in the same aquatic host. Co-infections bacteria + virus (e.g. Vibrio spp. + WSDV), and bacteria + parasite (e.g. Vibrio spp. + EHP) are extremely common in shrimp farming, having devastating effects worldwide in a broad range of farming scales and systems. Co-infections can significantly modify the course and the severity of different shrimp diseases, being either synergic or antagonist. Moreover, the susceptibility of shrimp to different infectious pathogens could be increased during concomitant infections, causing the appearance of acute shrimp outbreaks with higher incidence.
In this presentation, we report on the development of preventive and corrective feed additive strategies to minimize the impact of common co-infections and multiple infections in white-leg shrimp intensive farming. The results of trials conducted both in the laboratory and in the field in situations of co-infection (WSDV + Vibrio spp. and EHP + AHPND/EMS) and multiple infection (WSDV + IMNV + EHP + Vibrio spp.) will be presented. These results are encouraging in terms of preventive and corrective medicine through the use of functional additives. As a result of these farm and laboratory trials, preventive and corrective feed additive strategies have been validated as effective tools to minimize the impact of co-infections and multiple infections in shrimp farming and therefore, improve profitability of shrimp farming activities.