1. Division of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, University of Zurich, Rämistrasse 100, 8091 Zurich, Switzerland
2. Paul Ehrlich Institute, Paul-Ehrlich-Strasse 51-59, 63225 Langen, Germany
3. Regional Hospital Bamenda, PO Box 863 Mankon-Bamenda, Cameroon
4. District Hospital Kumba, Meme Division, South-West Region, Cameroon
5. District Hospital Ndop, Ngoketunjia Division, North-West Region, Cameroon
6. Regional Hospital Ngaoundere, Avenue Rue Ahidjo Ngaoundéré, Adamawa, Cameroon
7. Institute of Medical Virology, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland