Published Online: March 2, 2009 (doi:10.1001/jama.2009.297).
Author Contributions: Dr Gooskens had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Study concept and design: Gooskens, Claas, van den Broek, Kroes.
Acquisition of data: Gooskens, Jonges, Claas.
Analysis and interpretation of data: Gooskens, Jonges, Claas, Meijer, Kroes.
Drafting of the manuscript: Gooskens, van den Broek.
Critical revision of the manuscript for important intellectual content: Gooskens, Jonges, Claas, Meijer, Kroes.
Statistical analysis: Jonges.
Obtained funding: Meijer.
Administrative, technical, or material support: Jonges, Claas.
Study supervision: Gooskens, Claas, Meijer, van den Broek, Kroes.
Financial Disclosures: Mr Jonges reported being funded by the Impulse Veterinary Avian Influenza Research in the Netherlands program of the Economic Structure Enhancement Fund. No other authors reported financial disclosures.
Funding/Support:The Dutch GP surveillance network provided respiratory specimens for virological surveillance of influenza-like illness from which viral sequences were included in this analysis for comparison.
Role of the Sponsor: The Economic Structure Enhancement Fund and the Dutch GP surveillance network were not involved in the design and conduct of the study; collection, management, analysis, and interpretation of the data; or in the preparation, review, or approval of the manuscript.
Additional Contributions: We thank Gé A. Donker, PhD, NIVEL Netherlands Institute for Health Services Research, who is the coordinator of the Dutch GP sentinel surveillance network. Dr Donker was not financially compensated for providing the surveillance isolates.