TRANSMISSION OF A HIGHLY DRUG-RESISTANT STRAIN (STRAIN W1) OF MYCOBACTERIUM-TUBERCULOSIS - COMMUNITY OUTBREAK AND NOSOCOMIAL TRANSMISSION VIA A CONTAMINATED BRONCHOSCOPE

Context.-Nosocomial transmission of multidrug-resistant tuberculosis ( MDR TB) has been reported primarily in New York State and has generall y been presumed to occur via respiratory aerosols. Objective.-To asses s nosocomial transmission of MDR TB. In 1995, 8 patients with MDR TB w ere identified in South Carolina; all were resistant to 7 drugs and ha d matching DNA fingerprints (strain W1). Community links were identifi ed for 5 patients (Patients 1-5). However, no links were identified fo r the other 3 patients (Patients 6-8) except being hospitalized at the same hospital as 1 community patient. Design.-Outbreak investigation. Setting.-Community and hospital. Patients.-Eight patients whose MDR T B isolates had DNA fingerprint patterns matching strain W1. Main Outco me Measures.-Clinical characteristics of patients with strain W1 Mycob acterium tuberculosis isolates. Results.-Patient 5 (community patient) and Patient 8, diagnosed April 1995 and November 1995, respectively, had clinical courses consistent with MDR TB, with smear-positive and c ulture-positive specimens and cavitary lesions on chest radiograph; bo th died of MDR TB less than 1 month after diagnosis. Patients 6 and 7 (diagnosed May 1995) each had 1 positive culture for MDR TB; specimens were collected during bronchoscopy. Patient 6 had a skin test convers ion after bronchoscopy. Neither Patient 6 nor Patient 7 had a clinical course consistent with MDR TB, neither was treated for MDR TB, and bo th are alive and well. No evidence of laboratory contamination of spec imens, transmission on inpatient wards, or contact among patients was found. All 4 received bronchoscopies in May 1995; Patients 6, 7, and 8 had bronchoscopies 1, 12, and 17 days, respectively, after Patient 5. Observations revealed that bronchoscope cleaning was inadequate, and the bronchoscope was never immersed in disinfectant. Conclusions.-Inad equate cleaning and disinfection of the bronchoscope after the procedu re performed on Patient 5 led to subsequent false-positive cultures in Patients 6 and 7 and transmission of infection to Patient 6 and activ e MDR TB to Patient 8.