In addition to the authors, the following members of the GeoSentinel Surveillance Network contributed data: Kevin C. Kain, University of Toronto, Toronto, Ontario, Canada; Phyllis E. Kozarsky and Carlos Franco-Paredes, Emory University, Atlanta, Georgia, USA; Louis Loutan and François Chappuis, University of Geneva, Geneva, Switzerland; Joseph Torresi and Graham Brown, Royal Melbourne Hospital, Melbourne, Victoria, Australia; DeVon C. Hale and Stefanie S. Gelman, University of Utah, Salt Lake City, Utah, USA; Alice Pérignon, Hôpital Pitié-Salpêtrière, Paris, France; Gerd-Dieter Burchard, Bernhard-Nocht-Institute for Tropical Medicine, Hamburg, Germany; Mary E. Wilson, Harvard University, Cambridge, Massachusetts, USA; Fabrice Simon and Jean Delmont, Hôpital Nord, Marseille, France; William M. Stauffer and Patricia F. Walker, University of Minnesota, Minneapolis, Minnesota, USA; Poh Lian Lim and Annelies Wilder-Smith, Tan Tock Seng Hospital, Singapore; Jose Antonio Perez Molina, Hospital Ramon y Cajal, Madrid, Spain; Bradley A. Connor, Cornell University, Ithaca, New York, USA; Carmelo Licitra and Antonio Crespo, Orlando Regional Health Center, Orlando, Florida, USA; David O. Freedman, University of Alabama at Birmingham, Birmingham, Alabama, USA; Effrossyni Gkrania-Klotsas, Addenbrooke's Hospital, Cambridge, UK; Giampiero Carosi and Francesco Castelli, University of Brescia, Brescia, Italy; Marc Shaw, Worldwise Travelers Health and Vaccination Centre, Auckland, New Zealand; Prativa Pandey, CIWEC Clinic Travel Medicine Center, Kathmandu, Nepal; R. Bradley Sack and Robin McKenzie, Johns Hopkins University, Baltimore, Maryland, USA (Dec 1997–Aug 2007); Elizabeth D. Barnett, Boston University, Boston, Massachusetts, USA; Christina M. Coyle and Murray Wittner, Albert Einstein School of Medicine, Bronx, New York, USA; Stefan Hagmann and Andy Miller, Bronx-Lebanon Hospital Center, Bronx; Michael W. Lynch, Fresno International Travel Medical Center, Fresno, California, USA; Vanessa Field, InterHealth, London, UK; Michael D. Libman and J. Dick Maclean, McGill University, Montreal, Quebec, Canada; Alejandra Gurtman, Mount Sinai Medical Center, New York, New York, USA (Oct 2002–Aug 2005); Shuzo Kanagawa and Yasuyuki Kato, International Medical Center of Japan, Tokyo, Japan; and Patricia Schlagenhauf, Rainer Weber, and Robert Steffen, University of Zürich, Zürich, Switzerland.