Tuberculosis surveillance in a state prison system.

After four inmates at two New Mexico prisons converted their tuberculosis skin tests, a mass screening program was carried out at all the State's adult correctional facilities (2,240 inmates). Previously unknown converters were found with a disproportionally high per cent of converters (6.8 per cent and 6.3 per cent) and reactors (14.4 per cent and 12.2 per cent) at the first two prisons. No index cases were found. State policy has been revised to include two-stage skin testing of new inmates, annual testing thereafter, and screening of all new correctional staff.