1. Centre for Infectious Diseases, University of Edinburgh, Summerhall, Edinburgh EH9 1QH, Scotland
2. Global Viral Forecasting, One Sutter, Suite 600, San Francisco, California 94101
3. Helsinki University Central Hospital Laboratory Division, Helsinki, Finland
4. Limbe Wildlife Centre, BP 878, Limbe, Cameroon
5. Ape Action Africa, BP 20072, Yaounde, Cameroon
6. Projet Prevention du Sida ou Cameroun (PRESICA), Yaoundé, Cameroon
7. Department of Zoology, University of Oxford, Oxford OX1 3PS, United Kingdom
8. Blood Systems Research Institute and Department of Laboratory Medicine, University of California—San Francisco, San Francisco, California 94118
9. UMR145, Institut de Recherche pour le Développement and Department of International Health, University of Montpellier 1, 34394 Montpellier Cedex 5, France
10. Department of Virology, Haartman Institute, University of Helsinki, Helsinki, Finland
11. Department of Human Biology, Stanford University, Stanford, California