OBJECTIVE: To investigate a pseudo-outbreak of "Mycobacterium paraffinicum" (unofficial taxon) infection and/or colonization, using isolates recovered from clinical and environmental specimens. DESIGN: Outbreak investigation. SETTING: University-affiliated, tertiary-care hospital. METHODS: M. paraffinicum, a slow-growing, nontuberculous species of mycobacteria, was recovered from 21 patients and an ice machine on a single patient care unit over a 2.5-year period. The clinical, epidemiological, and environmental investigation of this pseudo-outbreak is described. RESULTS: Twenty-one patients with pulmonary symptoms and possible risk factors for tuberculosis were admitted to inpatient rooms that provided airborne isolation conditions in 2 adjacent hospital buildings. In addition, 1 outpatient had induced sputum cultured for mycobacteria in the pulmonary function laboratory. Of the samples obtained from these 21 patients, 26 isolates from respiratory samples and 1 isolate from a stool sample were identified as M. paraffinicum. Environmental isolates obtained from an ice machine in the patient care unit where the majority of the patients were admitted were also identified as M. paraffinicum. CONCLUSIONS: An epidemiological investigation that used molecular tools confirmed the suspicion of a pseudo-outbreak of M. paraffinicum infection and/or colonization. The hospital water system was identified as the source of contamination.
OBJECTIVE: To investigate a pseudo-outbreak of "Mycobacterium paraffinicum" (unofficial taxon) infection and/or colonization, using isolates recovered from clinical and environmental specimens. DESIGN: Outbreak investigation. SETTING: University-affiliated, tertiary-care hospital. METHODS:M. paraffinicum, a slow-growing, nontuberculous species of mycobacteria, was recovered from 21 patients and an ice machine on a single patient care unit over a 2.5-year period. The clinical, epidemiological, and environmental investigation of this pseudo-outbreak is described. RESULTS: Twenty-one patients with pulmonary symptoms and possible risk factors for tuberculosis were admitted to inpatient rooms that provided airborne isolation conditions in 2 adjacent hospital buildings. In addition, 1 outpatient had induced sputum cultured for mycobacteria in the pulmonary function laboratory. Of the samples obtained from these 21 patients, 26 isolates from respiratory samples and 1 isolate from a stool sample were identified as M. paraffinicum. Environmental isolates obtained from an ice machine in the patient care unit where the majority of the patients were admitted were also identified as M. paraffinicum. CONCLUSIONS: An epidemiological investigation that used molecular tools confirmed the suspicion of a pseudo-outbreak of M. paraffinicuminfection and/or colonization. The hospital water system was identified as the source of contamination.