Nontuberculous mycobacteria in patients registered in a tuberculosis control program in Southwestern Colombia, 2014-2017

Abstract

Introduction: Pulmonary disease produced by nontuberculous mycobacteria and pulmonary tuberculosis can share clinical signs and symptoms. It is important to discern one from the other in order to provide the proper treatment and programmatic management. Objective: To describe the frequency of nontuberculous mycobacteria isolated from patients registered in the tuberculosis control program in Cali. Methods: We conducted a descriptive study to know what extent of the pulmonary tuberculosis load in Cali-Colombia corresponds to nontuberculous mycobacteria, in a four-year period, 2014-2017. Demographic (sex, age, health insurance), clinical (diagnosis dates, laboratory data, comorbidities) and programmatic data (tuberculosis treatment initiation and duration) was collected for statistical analysis. Results: Of 3,651 patients registered in the local tuberculosis program with an initial diagnosis of pulmonary tuberculosis, 2,904 had sputum culture and among them 1.5% (43/2904) had nontuberculous mycobacteria isolation rather than Mycobacterium tuberculosis. Most of the nontuberculous mycobacteria isolates were not identified at the species level; M. fortuitum and M. abscessus were the most common species identified. 86% of patients initiated unnecessary tuberculosis treatment. Conclusion: Nontuberculous mycobacteria isolation from pulmonary samples could be frequent in patients registered in the tuberculosis program in Cali, Colombia. The lack of clinical suspicion, the limited laboratory infrastructure, and the absence of a reporting system could be contributing factors to underestimate the importance of nontuberculous mycobacteria in this setting. We recommend that nontuberculous mycobacteria identification should be considered for public health intervention.