Transmission of atypical Myeobacteria by a fiberoptic bronchoscopc leading to a pseudo-outbreak of tuberculosis

Abstract

INTRODUCTION: Failure to eradicate contamination of bronchoscopes that occur during use may lead to person-to-person transmission of Mycobacterium tuberculosis or pseudo-outbreaks from environmental microbes such as nontuberculous mycobacteria. OBJECTIVE: To determine the rate of detection of Mycobacterium strains from sputum and bronchial wash preparations of patients, and the extent of nosocomial transmission of Mycobacterium strains following bronchoscopy, and to determine whether results of smear examination for acid fast bacilli (AFB) can mislead the diagnosis and management of patients. DESIGN ANDSETTING: 107 sputum and 60 broncho alveolar lavage (BAL) samples received from patients suspected of tuberculosis and microbiological specimens from the fiberoptic bronchoscope at the Teaching Hospital, Ragama from January 2001 to October 20027 . METHODS: All samples were stained for AFB with Ziehl-Neelsen stain. Samples which were positive by the stain were inoculated into the Lowenstein-Jensen medium and Para-nitro benzoic acid (PNB) containing medium for culture. RESULTS: 13 of 107 patients' sputum and 39 of 60 patients' BAL samples and the saline wash specimen of the bronchoscope were positive for AFB stain. Sputum of 12/13, BAL samples of 22/39 patients and the saline wash specimen were cultured, 1/12 sputum and 8/22 BAL and the saline wash specimen yielded a growth of an atypical CONCLUSIONS: This study reveals a pseudo-outbreak of acid fast bacilli amongst patients with respiratory disease due to the transmission of non-tuberculous mycobacteria by a fiberoptic bronchoscope indicating the value of positive AFB in BAL for predicting pulmonary tuberculosis is questionable.