A study published in the June issue of the International Journal of Tuberculosis and Lung Disease indicates that certain clinical symptoms suggest a suspicion of pulmonary tuberculosis in patients with negative sputum bacterioscopy.

A positive result from sputum bacterioscopy is observed in approximately half of patients with a confirmed diagnosis of pulmonary tuberculosis. At the same time, a cultural study of sputum, rapid tests to detect mycobacterium tuberculosis and sometimes X-ray studies are not available in many developing countries, so it is extremely important to determine the clinical criteria for the diagnosis of pulmonary tuberculosis in patients with negative bacterioscopy results.

This study was carried out in Guinea (Africa) as part of the National Tuberculosis Program. We examined 396 patients who had complained of cough for more than 3 weeks and whose bacterioscopic results of sputum were negative. Upon admission, patients underwent clinical and radiological studies, a tuberculin test and an HIV antibody test, and then amoxicillin was prescribed at a dose of 1.5 g per day orally for 10 days. Control studies were performed on day 14.

Among the patients examined, 26 (13.8%) infected with HIV were found. Of the 272 patients whose treatment with amoxicillin was not effective, 155 had a positive sputum test result and were excluded from the study, and the other 117 patients received specific anti-tuberculosis treatment, including results were evaluated on the 75th day of treatment.

Of these 117 patients, a positive culture test (growth M. tuberculosis) was observed in 73, negative in 43 and lung cancer was detected in 1 patient. In addition, in all patients with a positive result from a culture study and in 37/43 patients with a negative result, the efficacy was noted and a complete cycle of specific anti-tuberculosis treatment was completed.

Thus, the presence of a cough without sputum production in young people (under 37 years), the ineffectiveness of antibiotic treatment, a positive result of the tuberculin test, HIV infection, changes in the chest x-ray ( caries, inhomogeneous infiltration) can suspect pulmonary tuberculosis with a negative result the result of bacterioscopy. In the absence of radiographic data, the main diagnostic criterion for pulmonary tuberculosis is the ineffectiveness of antibiotic treatment.