Origin and management of primary and acquired drug-resistant tuberculosis in The Netherlands: the truth behind the rates.

The Netherlands, May 1994 to May 1996. 1) To estimate to what extent drug-resistant tuberculosis was acquired or recently transmitted in The Netherlands, 2) to assess the relevance of drug resistance data as routinely collected, and 3) to describe case management. Prospective descriptive study. Patients diagnosed with drug-resistant tuberculosis were interviewed. Information on patient management and contact tracing was collected. IS6110 restriction fragment length polymorphism (RFLP) patterns of all strains were compared with those of the National RFLP library and clusters were analyzed. In total 193 cases were included in the study. Acquired drug resistance (ADR) was rare. Dutch ADR patients reported receiving treatment a long time previously (mean age 58, mean treatment interval 23 years). Most foreign ADR patients had been treated recently in their country of origin. Of 151 primary drug-resistant (PDR) cases, 129 (85%) were foreign-born, of whom few (8%-19%) had been infected in The Netherlands. Few Dutch PDR cases had been infected recently (mean age 49 years). Rifampicin resistance was more frequently observed in foreign ADR cases than in foreign PDR cases (28% vs 5%; P < 0.001). One third of cases had not been treated according to treatment guidelines. Only a small proportion of drug-resistant cases resulted from recent infection or treatment in The Netherlands. General rates of ADR and PDR do not reflect current Dutch programme performance. For programme monitoring, ADR/PDR rates and their trends must be reported and evaluated in Dutch and foreign patients separately.