Diseases from fish
- Anisakiasis (worms in raw fish)
Anisakiasis is an infection with the marine fish Anisakis roundworm (Anisakis simplex). People can get infected when they ingest the immature stages of the worm (larvae) in raw or undercooked infected fish in dishes such as sushi, sashimi, ceviche, and pickled herring. Symptoms usually occur within hours of eating and may include nausea, vomiting, diarrhea, and abdominal pain. If the larvae pass into the bowel, symptoms mimicking Crohn's disease may occur after 1-2 weeks. In some cases the larvae migrate from the stomach to other tissues and severe allergic reactions can occur. The larvae can be killed by cooking fish to 140ºF (60ºC) for 10 minutes, freezing fish at -4ºF (-20ºC) for at least 7 days, or blast freezing fish to -31ºF (-35ºC) for 15 hours.
- Fish tank granuloma (mycobacteriosis)
Fish tank granuloma is an infection caused by Mycobacterium marinum. These bacteria are widespread in aquatic environments and often occur in aquarium fish or food fish raised under crowded conditions. Before chlorination, outbreaks of mycobacteriosis occurred in contaminated swimming pools. People can get infected through direct contact with contaminated water sources, including aquarium water. The bacteria enter through breaks in the skin. The infection can cause skin lesions, usually on the fingers or hands. Skin lesions may heal or in some cases may persist for months. In persons with weakened immune systems, the bacteria may cause joint and bone infections. To prevent infection persons who clean aquariums should wear gloves and wash their hands thoroughly afterwards.
- Salmonellosis - Aquariums
Salmonellosis is an infection of the intestines caused by a group of bacteria called Salmonella. The bacteria are shed in the stool of infected animals and humans. Infection can happen when a person eats food or drinks water or milk that has been contaminated with Salmonella bacteria. Salmonella bacteria have also been found in tropical fish and home aquariums. Infection with Salmonella can cause serious disease especially in children younger than 5 years of age, the elderly, and persons with weakened immune systems.