Fish as a potential source of human bacterial infection

Bacteria are the most common pathogens of cultured warm water fish, and cause major losses to the freshwater aquaculture in Egypt and elsewhere. Fish species commonly affected include carp, tilapia, eel, catfish, salmon and trout. Many potentially pathogenic bacteria of fish normally exist in a commensal association with the host or live free in the environment. Both these types of bacteria become pathogenic when the fish is immuno-compromised by some form of stressors. Human infections caused by pathogens transmitted from fish or the aquatic environment are quite common and depend on the patients, contact with fish and related environment, dietary habits and the immune system status of the exposed individual. They are often bacterial species facultative pathogenic for both fish and human beings and may be isolated from fish without apparent symptoms of the disease. The infection source may be fish kept for both for food and as a hobby.