Abstract

PENATA, Adrián et al. Molecular diagnosis of extrapulmonary tuberculosis and sensitivity to rifampicin with an automated real-time method . Biomédica [online]. 2016, vol.36, suppl.1, pp.78-89. ISSN 0120-4157.  https://doi.org/10.7705/biomedica.v36i3.3088.

Introduction: Tuberculosis continues to be a global public health problem, the extrapulmonary form being estimated to occur in 10-20% of immunocompetent individuals, increasing in patients who are carriers of the human immunodeficiency virus (HIV); its diagnosis is difficult with conventional methods due to the paucibacillary nature of samples. The Xpert ® MTB/RIF test represents an important development in the molecular detection of Mycobacterium tuberculosis and has been used with a variety of non-respiratory clinical samples. Objective: To determine the effectiveness of Xpert ® MTB/RIF in the detection of M. tuberculosis and sensitivity to rifampicin in patients with suspected extrapulmonary tuberculosis attending Hospital Universitario de San Vicente Fundación in Medellín in 2013-2014. Materials and methods: This was a descriptive, cross-sectional ambispective study of 372 consecutive samples from 301 patients with suspected extrapulmonary tuberculosis, who were subjected to bacilloscopy, followed by culture in Ogawa Kudoh and the Xpert ® MTB/RIF molecular test. Results: The most frequent base diagnosis (60%) for the 182 patients was infection with HIV. Using the culture as reference, the sensitivity and general specificity of the molecular test was 94% (95% CI: 83-100) and 97% (95% CI: 95-99), respectively; for bacilloscopy it was 38.71(95% CI: 19-57) and 100% (95% CI: 99-100), respectively. Sensitivities higher than 75% were found in analyses stratified by samples. Thirty-seven of the isolates were sensitive and one resistant to rifampicin. Conclusion: Xpert ® MTB/RIF performed well in samples from different tissues and liquids, representing a significant advance in support of extrapulmonary tuberculosis diagnosis in terms of time and percentage positivity.

Keywords : Mycobacterium tuberculosis; tuberculosis; miliary; polymerase chain reaction; DNA; rifampin.

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