Discrimination of productive and non-productive cough by sound analysis

SETTING: Sixteen districts of Budapest, Hungary. OBJECTIVE: To determine the frequency of primary and secondary drug resistance, and to recommend treatment regimens. DESIGN: A retrospective survey. METHODS: Mycobacterium tuberculosis isolates were collected from 264 newly diagnosed and 147 previously treated patients. All strains were tested against isoniazid (INH), rifampicin (RIF), streptomycin (SM) and ethambutol (EMB) using the proportion method. Bacteriologic examinations were performed in the Diagnostic Laboratory of the Koranyi National Institute for Tuberculosis and Pulmonology in Budapest. RESULTS: Primary resistance to INH alone was 4%, to SM alone 2%, to RIF alone 0.4%, to INH and SM 1%, and to INH, RIF, SM and EMB 0.4%. Of the isolates of 78 relapse cases, six (8%) were resistant to INH alone, one (1%) to INH and RIF, two (3%) to INH, RIF, SM and EMB. Of the isolates of 69 patients notified with active tuberculosis for over a year, 51 (74%) were susceptible to the drugs tested. CONCLUSION: Based on the level of primary drug resistance as well as on the resistance pattern of relapse cases, it is recommended to start the treatment of newly detected and relapse cases with four drugs. The high rate of chronic cases with susceptible strains can be explained by poor compliance. To prevent development of resistant cases and to achieve good compliance, it is necessary to apply direct observation of treatment in all types of patients.