Figure 3. Mumps immunity status and compliance among employees, Northwestern Memorial Hospital, Chicago, Illinois, USA, 2006. Black bars, no. employees with history of immunity; white bars, no. employees who complied with required antibody titer testing; red bars, no. employees who did not comply with required antibody titer testing; black line, percent of employees in compliance. Unit staff consisted of nurse managers, secretaries, patient care technicians, clinical coordinators, and emergency department assistants; nonunit staff consisted of applications analysts, counselors, radiographers, resource coordinators, respiratory therapists, records specialists, safety technicians, patient escorts, housekeeping workers, and food services workers.