Abstract
Occupational exposures to Mycobacterium tuberculosis and bloodborne pathogens were evaluated during the processing of medical waste at a commercial treatment site. The facility utilized a method consisting of shredding waste followed by disinfection with dielectric heat. A previous epidemiologic investigation revealed three employees with active tuberculosis, the etiologic agent in each case having a different drug susceptibility pattern. This finding eliminated the possibility of person-to-person transmission between employees. Further evaluation confirmed that one employee was infected with a strain of M. tuberculosis identical to an isolate recovered from a patient treated at a clinic that sent waste to the treatment facility. Factors contributing to exposures included: the aerosolization of products contained in the waste, deficiencies in the facility design, absence of safety policies, inadequate design and operation of processing equipment. Furthermore, misunderstandings among employees regarding equipment operating procedures, use of personal protective equipment, and routes of disease transmission may have also been involved in employees exposures.