Microbiological diagnosis of tuberculosis. 20 years in the province of Soria. Performance and basic opportunities of improvement

OBJECTIVE: The aim of the study was to describe the bacteriological diagnosis of the tuberculosis in the province of Soria (Spain), as well as to analyse the techniques diagnostic performance and the use of the microbiology laboratory regarding tuberculosis. METHODS: An observational, descriptive and retrospective study was designed, including all patients with tuberculosis of any location that had their residence in the province of Soria. The period of study included patients diagnosed between 1994 and 2013 and a 24 months follow-up after the beginning of treatment was realized. RESULTS: A total of 337 patients were detected during the studied period. No sample was sent to the microbiology laboratory in more than 3% of the patients (23% in skeletal tuberculosis and 33% in lymphatic tuberculosis). Bacteriological confirmation was obtained in 80% and 32% were smear-positive. Specimens were culture on solid and in liquid media; 10% of the strains were only isolated in one type of media. There were 2.9% isoniazid-resistant strains, 0.3% multi-drug resistant strains, and 0.3% rifampicin-resistant strains. A total of 36% of smear-positive pulmonary tuberculosis patients had no specimens sent for a follow-up study. CONCLUSIONS: It is essential to combine the use of a liquid and a solid medium. Physicians should be encouraged to submit specimens for mycobacteriological diagnostic and follow-up.