What are the symptoms of mycobacteriosis in humans?
It is not yet known whether Mycobacterium shottsii (the dominant species isolated in the current outbreak of striped bass mycobacteriosis in Chesapeake Bay) can infect humans. Concern is warranted because M. shottsii is closely related to M. marinum, a species known to cause disease in both humans and fish. Primary symptoms of human infection by M. marinum include infections of the skin and soft tissues. Infection most typically becomes evident as reddish raised nodules on the hands, elbows, knees, and feet. In many instances the joints may become swollen. M. shottsii and M. marinum have very different growth rates. M. marinum grows well at 30-33°C (86-91°F), but not at the normal human body core temperature of 37°C (98.6°F). This helps explain why M. marinum tends to infect the extremities, which are cooler than the body core. M. shottsii prefers a cooler temperature (23°C or 73°F) and grows very slowly or not at all at 30C under laboratory conditions.
