NATIONWIDE SURVEILLANCE OF DRUG-RESISTANT TUBERCULOSIS IN THE NETHERLANDS - RATES, RISK-FACTORS AND TREATMENT OUTCOME

SETTING: The Netherlands, 1993 and 1994. OBJECTIVE: To determine 1) ra tes of drug resistance in relation to nationality and country of birth , 2) risk factors for drug resistance, 3) treatment outcome of drug-re sistant cases, and 4) rates of primary and acquired drug resistance. D ESIGN: Retrospective study of all cases notified with bacillary tuberc ulosis in The Netherlands in 1993 and 1994. RESULTS: Drug resistance t o one or more drugs was reported in 268 (14.6%) of all 1836 cases, of whom 203 (76%) were foreign born. In Dutch patients rates of isoniazid (H) (2.9%) and streptomycin resistance (3.6%) were lower than in fore ign patients (8.6% and 10.6% respectively, P < 0.001). Multidrug (H an d rifampicin [R]) resistance was reported in 0.5% of Dutch-born and 1. 4% of foreign cases (P = 0.055). Rates of acquired resistance to H (11 .4%) and HR (5.7%) were higher than rates of primary resistance to the se drugs (5.2% and 0.7% respectively, P < 0.05), but the number of ret reatment cases was low (6.8% of all cases). Drug resistance was associ ated with immigration but not with drug use, homelessness or human imm unodeficiency virus (HIV) co-infection. One fifth (20%) of drug-resist ant cases was diagnosed by active case finding. Treatment outcome in s ensitive and resistant cases was compared. CONCLUSION: These findings suggest that drug resistance is imported, but it is unclear to what ex tent drug resistance among foreigners has been transmitted or created in The Netherlands. Drug resistance data should be monitored in Dutch and foreign patients separately.