Healthcare Worker-Related Tuberculosis Exposure

ISSUE: Boston Medical Center (BMC) is a 547-bed urban teaching hospital. On 6/3/05, the Boston Public Health Commission (BPHC) identified a healthcare worker (HCW) whose sputum was positive for acid fast bacillus (AFB). The HCW was immediately removed from patient care duties and empiric therapy with 4 drugs was initiated. The organism was identified as Mycobacterium tuberculosis on 6/13/05. PROJECT: BPHC determined that the HCW was potentially infectious from 12/1/04 until 6/2/05. During that time, the HCW performed clinical duties at 4 hospitals in MA. In collaboration with the MA Department of Public Health and the Centers for Diseases Control and Prevention, BPHC developed a contact investigation protocol. All institutions used the same exposure definitions and dates to identify potentially exposed patients and HCW. Data from all 4 institutions were entered into a shared database that was managed by BPHC. Within the next 6 weeks, all potentially exposed HCW had mandatory baseline tuberculin skin tests (TST) or symptom screen. Patients were offered free screening. Anyone whose last potential exposure occurred within 3 months of the baseline test was re-screened beginning in September 2005. At BMC, anyone with a positive TST or symptom screen was referred to the on-site Tuberculosis (TB) Clinic for evaluation. RESULTS: As of 12/15/05, 1514 patients, 1482 HCW had been screened at BMC. BPHC identified a small number of potentially exposed patients and HCW who met the definition for TST conversion and had no other identified risk factors. No patient or HCW developed active disease. LESSONS LEARNED: A TB exposure occurred despite having the following systems to prevent transmission of contagious infectious diseases in the workplace. 1. All HCW and students must have a baseline two-step TST upon hire and at least annually thereafter. 2. HCW with a positive TST must have a symptom screen and CXR. 3. HCW with symptoms or positive CXR are removed from patient care until evaluated by a healthcare provider with expertise in TB. 4. HCW must provide documentation of evaluation prior to being cleared for return to work. The ongoing challenge is to identify effective systems to facilitate early identification and treatment of potentially infectious HCW to prevent similar exposures in the future.