Patterns of drug resistance in pulmonary tuberculosis cases in the Izmir district, Turkey.

Antituberculosis drug resistance patterns were investigated among the new and previously treated pulmonary tuberculosis (TB) cases in Izmir district, retrospectively. Proportions of resistance patterns were determined using a number of resistant cases using as a denominator. Resistance to at least one drug was found in 304 (29.7%) patients in 1023 a total of tuberculosis cases. 182 new and 82 previously treated consecutive pulmonary tuberculosis cases were investigated. Patterns were examined as single and/or probable combinations of isoniazid (H), rifampicin (R), ethambutol (E) and streptomycin (S). Single drug resistance mode, mono S, and HS resistance patterns were the highest proportions in comparison with other modes and patterns in both new and previously treated cases. HRS pattern showed a significant proportion and proportions of quadruple mode were higher than triple mode in previously treated cases. Proportions of patterns associated with R were detected more than expected. Surveillance of proportions of anti-TB drug resistance is important as well as surveillance of resistance rates.