32 DECEMBER 2022 • WORLD AQUACULTURE • WWW.WA S .ORG individuals and select them as broodstock (Taengchaiyaphum et al. 2022). So, not everything about IHHNV is negative and this shows again that the evolution of the relationship between pathogen and host happens naturally. The basic principle and knowledge of the interaction among host, pathogen and environment, along with a holistic view of what is really a disease, is a concept that should be applied in decision making. There is one concept that should be clear: the presence of a pathogen is not the same as the presence of disease—one of the central dogmas of pathology. There is always the interaction of several factors such as the environment, the genetic makeup of the host, particular stress conditions, pond management, stocking densities used, and several other factors that are the ones that trigger what we know as disease in cultured shrimp and that eventually leads to death of a significant number of cultured animals. Due to the openness of some shrimp culture systems, to a greater or lesser extent, it is impossible to disinfect large volumes of water, both in intensive and extensive systems, regardless of the effort involved. RAS are an exception to this situation, where disinfection is possible and needed. All that can be done is to start the grow-out cycle with animals free from specific pathogens and/or tolerance/ resistance to them. It is highly probable that, during the grow-out cycle, some animals will get infected by one of the many viruses or other pathogens now known and maybe by some pathogen still unknown to the scientific community. In practical terms, for open culture systems, from semi-intensive to intensives, it is unrealistic to pretend to filter thousands of cubic meters of water and free it from all viruses and other possible potential pathogens, known and unknown. After an animal gets infected, either by the opportunistic pathogen on the list, or even by one unknown to the scientific community (and this might or will happen sooner or later in a cultured shrimp population), we will have to learn to live with the enemy, next to the enemy or surrounded by the enemy. Shrimp have done this for millions of years in the aquatic environment and aquaculturists will have to learn how to do it too. Along with this, regulations should evolve and adapt to the scientific evidence and results from field conditions in actual growout ponds. Keeping a virus such as IHHNV on a list of Obligatory Notifiable Diseases by a regulatory agency or authority only shows poor adaptation to advances and recent discoveries in the scientific field, pond data and production results obtained under practical field conditions. Let’s not forget the basic process that allowed us to progress and improve—evolution. This basic process and principle should apply to regulations as well. 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