Fish-borne illnesses

Fish-borne illnesses can be broadly divided into fish-borne intoxications and fish-borne infections (see table below). In the first case, the causative agent is a toxic compound that contaminates the fish or is produced by a biological agent in the fish. If the agent is biological, intoxication will occur even if the agent is dead as long as it has previously produced enough toxins to precipitate the illness symptoms. In the case of infections, the causative agent (bacteria, viruses or parasites) must be ingested alive, and then it invades the intestinal mucous membrane or other organs (infection) or produce enterotoxins (toxi-infection). It is worth noting that, apart from Vibrio species, L. monocytogenes and Cl. botulinum that are part of the indigenous fish flora, all the other micro-organisms that cause the majority of the fish-borne illnesses are caused by contamination from the environment, the handlers or the water. Protection from the environment, personal hygiene, education of fish handlers and water treatment (e.g. chlorination) are therefore essential in the control of fish-borne diseases.

Biotoxins

Finally, physical contaminants such as glass, metal and wood pieces, nails, bones in fish fillets have also been at the origin of consumer health distress and need to be considered when designing a safety assurance programme.