1. Department of Laboratory Medicine, University of California at San Francisco, San Francisco, CA 94118, USA
2. Blood Systems Research Institute, San Francisco, CA 94118, USA
3. Institute of Biomedical Sciences, Faculty of Medicine, University of Chile, Santiago, Chile
4. Laboratoire National de Santé Publique, 09 BP 24, Ouagadougou, Burkina Faso
5. Division of Infectious Diseases, Stanford University Medical Center, Stanford, CA 94305, USA
6. IDEXX Reference Laboratories, West Sacramento, CA 95605, USA