Mycobacteriosis is for real and has been with us for a while. It seems as if there has been more info put out about it this year, at least that is the impression I have. MA DMF has put out an advisory on Mycobacteriosis this year:
http://www.mass.gov/dfwele/dmf/marin...ion_050306.pdf .The striped bass does not have to have lesions to be infected - from MD DNR link posted above:
Are the signs of mycobacteriosis in fish always externally visible?
No. Mycobacteriosis in fish is generally first found in internal organs. In mild cases of this disease signs of infection may only be evident microscopically. As the disease progresses additional internal organs may show signs of disease. In severe cases virtually all organs and tissue are affected including the skin and muscle. Mycobacteria have been isolated from young-of-year striped bass but no visible signs of disease have been found. Infected 1- and 2-year-old fish typically exhibit mild to moderate signs of the bacteria. However 3- to 5-year-old fish have the highest incidence of mycobacteriosis, and occasionally exhibit severe infections, including emaciation and scar tissue formation on the skin. It is important to note that striped bass are susceptible to other viral, bacterial and parasitic infections; therefore not all striped bass with lesions on the skin have mycobacteriosis.
So, the fish that have the lesions must be pretty heavily infected, but the other fish that do not show outward signs can be infected too. The other thing is that a fish may have lesions, but that doesn't mean it is from mycobacteriosis, so I guess you should use caution when handling all stripers. How realistic is it to wear heavy rubber or cotton gloves when wading - or stop to put on those gloves when landing a fish - probably not going to happen...
Edited to add MA DMF link...