Fish Tuberculosis

I don’t want people to be afraid of fish tuberculosis, I want us to be informed about it. I have heard of people getting tuberculosis from their fish. I had questions about how this was possible and whether or not I should be worried about it. Fish tuberculosis (TB) is caused by the bacteria mycobacterium marinum. Human TB is caused by the bacteria mycobacterium tuberculosis. Fish Tb causes a skin infection in people. Fish and other aquatic organisms carry, or get bacteria which can be transmitted to humans. It is possible to get fish TB. It is difficult to get a diagnosis from a doctor for fish TB. Apparently there needs to be a culture taken from the infection site which then needs to be cultured properly. There is a very small risk of getting infectious diseases from our fish. In most cases the disease was contracted by the human having a wound and placing the wound into the aquarium with an infected fish.

Fish TB is not very contagious and if caught early will have a very small impact on the rest of your aquarium members. The best way to prevent fish TB is to feed a balanced diet and keep water clean and within normal chemical ranges (ammonia, nitrite and nitrate) Do not stick hands and arms into tanks or handle aquatic organisms, if you have an open or recent wound. You can wear long gloves to protect yourself when wounds are present. Sterilize hands and arms with chlorine water (use alcohol if there are wounds) after work in one tank and prior to working on another tank. Never start a tank siphon with mouth suction. If an injury occurs while working in a tank (or natural waters), let wound bleed freely for a while to push possible infecting bacteria back out of the body, then sterilize and protect wound. (Its way too late for me on most of these LOL).

Here is a list of symptoms your fish may have if they are infected, as you can see by the list it would be very difficult to diagnose as these symptoms are the same for many other fish illnesses.

loss of appetite

fish remains in seclusion and out of site rapid breathing (respiration)

eyes appear to be cloudy or “popping out”

fish lies on its side near bottom of aquarium

stomach of fish appears to be sunken

whitish blotches on exterior

Treatment of fish is 40grams of streptomycin and isoniazid. Treatment can be increased by adding streptomycin to the fishes food. If you suspect your fish may have had TB and has died and you want to disinfect you may want to try these methods. Mycobacterium sp. are more difficult to kill than most bacteria because they have a very thick waxy outer coat. This waxy coat, plus the clumping that occurs in some strains, make them a bit tougher to penetrate with common disinfectants. 65-90% alcohol increases the likelihood of killing it, but, as with chlorine, organics will diminish this response. Recommended use of bleach for initial reduction in organics will kill off most other pathogens, including some of the weaker strains of myco. However, it is also recommend following up with a 65-90% soak/spray with alcohol (after neutralization of chlorine and drying). Increased contact time will increase likelihood of kill, so, if possible, try wiping down and/or soaking materials for 15-30 minutes, with alcohol.

It appears at least one researcher is using zebra danios to research the TB disease and possibly help to find a cure for human TB you can read more about this here.

Other resources….