Author Contributions: Drs Griffith, Lewis, and Parise had full access to all of the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis.
Study concept and design: Griffith, Lewis, Parise.
Acquisition of data: Griffith, Lewis, Mali, Parise.
Analysis and interpretation of data: Griffith, Lewis, Parise.
Drafting of the manuscript: Griffith, Lewis, Parise.
Critical revision of the manuscript for important intellectual content: Griffith, Lewis, Mali, Parise.
Administrative, technical, or material support: Griffith, Lewis, Mali.
Study supervision: Parise.
Financial Disclosures: None reported.
Disclaimer: The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the Centers for Disease Control and Prevention.
Acknowledgment: We thank Phuc Nguyen-Dinh, MD, MPH, Malaria Branch, Division of Parasitic Diseases, Centers for Disease Control and Prevention (retired in February 2007), for his thorough review and critical comments on the manuscript. He did not receive any compensation for his contribution.