Nationwide surveillance of drug-resistant tuberculosis in The Netherlands: rates, risk factors and treatment outcome.
METHODS
The Netherlands, 1993 and 1994.


OBJECTIVE
To determine 1) rates of drug resistance in relation to nationality and country of birth, 2) risk factors for drug resistance, 3) treatment outcome of drug-resistant cases, and 4) rates of primary and acquired drug resistance.


METHODS
Retrospective study of all cases notified with bacillary tuberculosis in The Netherlands in 1993 and 1994.


RESULTS
Drug resistance to 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 foreign patients (8.6% and 10.6% respectively, P < 0.001). Multidrug (H and 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 these drugs (5.2% and 0.7% respectively, P < 0.05), but the number of retreatment cases was low (6.8% of all cases). Drug resistance was associated with immigration but not with drug use, homelessness or human immunodeficiency virus (HIV) co-infection. One fifth (20%) of drug-resistant cases was diagnosed by active case finding. Treatment outcome in sensitive and resistant cases was compared.


CONCLUSIONS
These findings suggest that drug resistance is imported, but it is unclear to what extent drug resistance among foreigners has been transmitted or created in The Netherlands. Drug resistance data should be monitored in Dutch and foreign patients separately.
Lambregts-van Weezenbeek
C S
CS
Royal Netherlands Tuberculosis Association (KNCV), The Hague, The Netherlands.
Jansen
H M
HM
Nagelkerke
N J
NJ
van Klingeren
B
B
Veen
J
J
D000995:Antitubercular Agents / Q000627:therapeutic use*; D016022:Case-Control Studies; D004352:Drug Resistance, Microbial; D004359:Drug Therapy, Combination; D004641:Emigration and Immigration; D005260:Female; D006801:Humans; D008297:Male; D009169:Mycobacterium tuberculosis / Q000187:drug effects; D009426:Netherlands / Q000453:epidemiology; D012042:Registries; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome; D018088:Tuberculosis, Multidrug-Resistant / Q000188:drug therapy / Q000453:epidemiology*
D000995:Antitubercular Agents