A Mycobacterium tuberculosis cluster demonstrating the use of genotyping in urban tuberculosis control
- Equal contributors
1 Department of Tuberculosis Control, Municipal Public Health Service Rotterdam-Rijnmond, P.O. Box 70032, 3000 LP Rotterdam, The Netherlands
2 Department of Public Health, Erasmus MC, University Medical Center Rotterdam, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands
3 National Mycobacteria Reference Laboratory, National Institute of Public Health and the Environment, P.O. Box 1, 3720 BA Bilthoven, The Netherlands
4 Division of Infectious Disease Control, Municipal Public Health Service Rotterdam-Rijnmond, P.O. Box 70032, 3000 LP Rotterdam, The Netherlands
BMC Infectious Diseases 2009, 9:151 doi:10.1186/1471-2334-9-151Published: 8 September 2009
DNA fingerprinting of Mycobacterium tuberculosis isolates offers better opportunities to study links between tuberculosis (TB) cases and can highlight relevant issues in urban TB control in low-endemic countries.
A medium-sized molecular cluster of TB cases with identical DNA fingerprints was used for the development of a visual presentation of epidemiologic links between cases.
Of 32 cases, 17 (53%) were linked to the index case, and 11 (34%) to a secondary case. The remaining four (13%) could not be linked and were classified as possibly caused by the index patient. Of the 21 cases related to the index case, TB developed within one year of the index diagnosis in 11 patients (52%), within one to two years in four patients (19%), and within two to five years in six patients (29%).
Cluster analysis underscored several issues for TB control in an urban setting, such as the recognition of the outbreak, the importance of reinfections, the impact of delayed diagnosis, the contribution of pub-related transmissions and its value for decision-making to extend contact investigations. Visualising cases in a cluster diagram was particularly useful in finding transmission locations and the similarities and links between patients.