[Resistant lung tuberculosis in Berlin 1987-1993]

Resistance of Mycobacterium tuberculosis (M. tb) strains is an increasing problem worldwide. Since no public health data are available for urban populations in Germany, we investigated resistance in our hospitalized patients (n = 1011) during the last seven years. We evaluated clinical data and results of susceptibility tests (break-point technique/proportion method) for isoniazid, streptomycin, rifampin, pyrazinamide, protionamide, and ethambutol. Since 1987 there has been a relatively constant rate of 5.9% (3.9-7.8%) for single-drug resistance (SDR) but an increasing rate of multidrug-resistant (MDR) strains (> or = 2 first-line drugs) from 1.7% in 1987 to 5.8% in 1993. 69% of patients with MDR strains showed resistance to two drugs and 31% to three or more drugs. Risk factors for SDR and MDR tuberculosis revealed previous therapy (odds ratio (OR) [CI95%] SDR: 2.2 [1.7-4.0]; MDR: 4.5 [2.3-8.8]) and foreign-born status (SDR: 2.2 [1.3-3.6]; MDR: 3.5 [1.8-6.8]) to be the most important factors associated with resistance (p < 0.006-0.0001). Both primary and acquired resistance was higher in foreign-born than in German-born patients (p < 0.005). There was a considerable increase in multidrug-resistant tuberculosis in our hospital during 1987 and 1993. Since previously treated patients and patients born in countries with a high level of primary resistance had an increased risk of drug-resistant tuberculosis, we would advise a four-drug regimen as initial therapy in those patients.