a1 Centre for Infectious Disease Control Netherlands, National Institute of Public Health and the Environment (RIVM/CIb), Bilthoven, The Netherlands
a2 European Programme for Intervention Epidemiology Training, European Centre for Disease Prevention and Control, Sweden
a3 Public Health Service Region Twente, Enschede, The Netherlands
a4 Laboratory for Medical Microbiology Twente Achterhoek, Enschede, The Netherlands
a5 Animal Health Service, Deventer, The Netherlands
a6 Food and Consumer Product Safety Authority, The Hague, The Netherlands
In 2006, in The Netherlands, an outbreak of Salmonella Typhimurium phage type 561 (STM DT7, corresponding to the rare DT7 in the international typing scheme) was detected, accumulating to over 200 cases. By telephone interviews, data were collected from all laboratory-confirmed cases. In addition, in August 2006, a case-control study was performed in a subset of cases. Environmental and microbiological investigation was performed on a suspected dairy farm. In the case-control study (51 cases, 105 matched controls), hard cheese purchased from a farm, specifically farm X, and from a market stall were found to be associated with infection. The dairy production room of farm X tested STM DT7-positive in August. However, it was only in November, after earlier unsuccessful attempts, that a low-level contamination was confirmed in the hard farmhouse cheese, triggering control measures. A timely and adequate response was hampered during this outbreak for several reasons. Measures for improvement in handling future similar incidents are discussed.
(Accepted February 04 2008)
(Online publication March 19 2009)
c1 Author for correspondence: Y. T. H. P. van Duynhoven, Ph.D., Head, Laboratory for Zoonoses and Environmental Microbiology, RIVM, Centre for Infectious Disease Control Netherlands, PO Box 1, 3720 BA, Bilthoven, The Netherlands. (Email: email@example.com)
† The remaining team members are listed in the Appendix.