The bacteria can be found in salt or fresh water and has historically been associated with surfboarding and more recently, fish tanks. The bacteria is harmless unless introduced to an open wound and infections are relatively rare, says Dr. William Schaffner, chair of the department of Preventive Medicine at Vanderbilt University School of Medicine.
Infections can sometimes heal on their own, but "it's a long-lasting infection and, without treatment, it can take one to two years to resolve," says Schaffner. Treatment consists of combinations of antibiotics and surgery.
Fending Off Fish Tank Frights
Mild skin infections with mycobacterium marinum are well-known among aquarium hobbyists, but the most famous disease risk among aquarium enthusiasts is salmonella, says Dr. Christopher Ohl, MD, an infectious diseases expert at Wake Forest University School of Medicine.
Salmonella outbreaks have been periodically tied to fish, amphibian, and reptile pets and the tanks they reside in; the most recent of which occurred this April when 216 people contracted Salmonella from pet African Dwarf Water Frogs.
Overall, however, fish tanks "pose very little risk" when properly maintained, notes Schaffner.
He recommends wearing latex gloves while cleaning pet tanks and washing hands and forearms with soap and water afterwards.
Ohl also recommends cleaning tanks outside or in a bathtub -- not in the kitchen sink, to reduce the risk of contamination. Wash the bathtub with bleach afterwards if used, he says. If you get a cut while cleaning a fish tank, wash the wound with soap and water immediately.