Many employee health programs perform skin-tests on employees after exposure to pulmonary tuberculosis. This activity has become standard in employee health programs. The scenario in most health care facilities involves employees who are exposed to patients with active pulmonary tuberculosis. Many of these patients have active disease that is not detected during their hospitalization, and personnel are exposed unknowingly. The diagnosis of tuberculosis is often made after the patient is discharged which may result in contact tracing of exposed employees. This activity seems straightforward at first glance but is usually time-consuming and cumbersome. The first questions often asked are: what constitutes a dangerous patient and what is the definition of an exposure?