Avaliação de um protótipo para coleta de Mycobacterium tuberculosis em aerossóis gerados pela tosse. Evaluation of a collection prototype for Mycobacterium tuberculosis aerosols generated by cough.

objectives: Developed a collection prototype for Mycobacterium tuberculosis aerosols generated by cough and recaptured by the Polymerase Chain Reaction (PCR) technique. methodology: The first phase evaluated the viability of the capturing of M. tuberculosis present in aerosols generated by cough. A prototype collection using Intersurgical Clear-Therm 3 filter + HME® with a FTA (Whatman Bioscience®) disc over the internal filter was developed. It was tested on a patient with bacillary lung tuberculosis, in a period of 8 hours, in the moments of spontaneous cough. The second phase was realized in patients with lung tuberculosis, or clinical suspicions. The patients were told to cough three times consecutively into the aerosol collection prototype that was composed of a plastic cup with a FTA disc (Whatman Bioscience®) in its interior. The recapturing performance rates of the airborne M. tuberculosis by the PCR was evaluated. Results obtained in the sputum baciloscopy and cultures were considered gold-standard. Results: The analysis of the collected material in the first phase reveal positive results in the PCR. In the second phase of the study, 18 patients were evaluated and 5 were excluded. Of the 13 remaining, 9 were of the masculine gender. The average age was 37.7 years (DP±10,4). Thirteen sputum baciloscopies were realized and 3 had positive results. Seven culture tests were realized with 5 positive results. The PCR technique had negative results. Conclusion: The recapturing of the bacilli by the first prototype confirms the effectiveness of the FTA disk and the PCR technique, on the other hand, the prototype evaluated in the second phase was not efficient in the recapturing of the microorganism.