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Your Fish Aquarium Could Make You Sick


Watching fish swim in a home aquarium can be relaxing, but there may be danger lurking in those shallow depths. Did you know your fish aquarium could make you sick? If you have a fish tank, read on.

What’s in your fish tank?

Pet fish owners know they must routinely clean their aquarium to help provide a safe, healthful environment for the fish and to prevent the development of any condition that could be harmful to the animals. This process typically includes syphoning off a certain percentage of the water in the aquarium about once a week and adding fresh water, vacuuming the bottom of the tank (including the gravel), cleaning any decorative objects in the aquarium, and changing filters when necessary.

Cleaning a fish tank can present dangers to pet owners as well, according to a new study from Henry Ford Hospital. The authors reported on a skin infection, seen among people who clean their aquariums, that is easy to miss or misdiagnose.

Henry Ford Hospital investigators explained that the organism known as Mycobacterium marinum, which can be found in contaminated home aquariums, can cause skin lesions that don’t appear for weeks after exposure. This long incubation period makes it difficult to properly diagnose and thus treat a M. marinum infection unless a patient and the doctor link cleaning a fish tank with the condition.

Typically, M. marinum enters the body through an open wound or scrape on the hand or arm that is exposed to the contaminated aquarium water. Skin lesions generally do not appear for two to four weeks after incubation.

George Alangaden, MD, the study’s lead author and an infectious disease physician, noted that “People just don’t know or think about their fish tank harboring this bacterial organism.” Making people aware of the connection could help affected individuals get prompt and proper treatment.

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In the retrospective study, which was presented at the Infectious Diseases Society of America’s annual meeting on October 5, the authors reported on five patients who were treated with antibiotics for a M. marinum infection. However, there was an average time span of 161 days from when the individuals first experienced symptoms until they were treated properly.

Symptoms and prevention of M. marinum infection
A Mycobacterium marinum infection is characterized by non-healing red bumps or skin lesions on the hands or arms. Some affected individuals experience itching, localized pain, and firmness where the infection appears, but others do not. The infection is not life-threatening.

Fever and chills are not common with this skin condition. However, anyone who has a compromised immune system or a serious illness may experience enlarged lymph nodes, fever, and a systemic infection. In rare cases, the infection can cause persistent ulceration or spread to the bone (osteomyelitis).

M. marinum is found in both salt and fresh water. The infection is known to affect more than 150 fish and other aquatic animals.

If you have a home aquarium, you can help avoid M. marinum infection by wearing waterproof gloves when cleaning your fish tank. Even if you wear gloves, you should wash your hands and forearms thoroughly with soap and water after cleaning the aquarium.

Most cases of M. marinum infection are associate with cleaning aquariums. However, it is also possible to become infected if you have a cut, sore, or scrape on your skin and you go into fresh or saltwater that is contaminated. Proper chlorination of swimming pools can kill the bacteria.


Image: Morguefile