1. Kliniken der Stadt Köln gGmbH, University Hospital Witten/Herdecke, Cologne, Germany
2. Department of Virology, Erasmus Medical Center Rotterdam, Rotterdam, The Netherlands
3. Department of Infectious Diseases, University of Georgia, Athens, Georgia 30602
4. United States Naval Medical Research Unit San Antonio, Department of Dental and Biomedical Research, Applied Laboratory Sciences Division, Ft. Sam Houston, Texas 78234
5. Laboratoire de Virologie, Centre Hospitalier Universitaire, Dijon, France
6. Vanderbilt University Medical Center, School of Medicine, Nashville, Tennessee 37232-2581