Tuberculosis contact investigation and DNA fingerprint surveillance in The Netherlands: 6 years' experience with nation-wide cluster feedback and cluster monitoring
OBJECTIVES: To describe the contribution of 6 years of nationwide DNA fingerprint surveillance to tuberculosis control in general and to conventional contact investigations in particular.
DESIGN: All Mycobacterium tuberculosis cultures are subjected to standardised IS6110-based RFLP typing, and clustered cases are systematically reported to the regional TB services involved (cluster feedback). Standardised questionnaires are used to collect information on contact investigations and epidemiological links (epi links) at regional level. Revision of the questionnaires for the period 1997–2000 allows comparison of epi linking before and after cluster feedback.
RESULTS: Among 2206 clustered cases, 462 (21%) epi links were expected before the RFLP result, whereas an additional 540 (24%) epi links were established after cluster feedback. Epi links based on documented exposure increased by 35%, from 357 to 550 (P < 0.001). Only 1% of contact investigations were extended, however, and relatively few additional persons with active or latent tuberculosis were diagnosed. Reasons for the limited impact on contact investigation outcome were 1) contact took place 1–7 years previously (51%), 2) documented contact involved a subsequent case in the cluster (21%), 3) casual contact (15.5%) and 4) different region (9%). Five per cent of epi links established by contact investigation were contradicted by RFLP data. Epi links were more frequently documented in Dutch (41%) than non-Dutch cases (19%, OR 3.0; 95%CI 1.41–1.91). Cluster monitoring permitted: 1) identification of transmission chains that could not be detected by contact investigations, 2) development and evaluation of targeted interventions, and 3) identification of professional failures and poor programme performance.
CONCLUSIONS: RFLP surveillance forms the bridge between conventional contact investigation and other forms of targeted active case finding. Combining both complementary strategies in a comprehensive approach to systematic outbreak monitoring and management allows countries in the elimination phase of the disease to better target and evaluate TB control interventions.
Document Type: Regular Paper
Affiliations: 1: Royal Netherlands Tuberculosis Association (KNCV), The Hague, The Netherlands 2: Municipal Health Service, Rotterdam, The Netherlands 3: National Institute of Public Health and the Environment (RIVM) Bilthoven, The Netherlands
Publication date: 2003-12-01
The International Journal of Tuberculosis and Lung Disease publishes articles on all aspects of lung health, including public health-related issues such as training programmes, cost-benefit analysis, legislation, epidemiology, intervention studies and health systems research. The IJTLD is dedicated to the continuing education of physicians and health personnel and the dissemination of information on tuberculosis and lung health world-wide.
Certain IJTLD articles are selected for translation into French, Spanish, Chinese or Russian. They are available on the Union website
- Editorial Board
- Information for Authors
- Subscribe to this Title
- International Journal of Tuberculosis and Lung Disease
- Public Health Action
- Ingenta Connect is not responsible for the content or availability of external websites