1. Center for International Health, University of Bergen, N-5020 Bergen, Norway
2. Walter Reed/AFRIMS Research Unit Nepal, Kathmandu 44600, Nepal
3. Department of Research, Innlandet Hospital Trust, N-2381 Lillehammer, Norway
4. Department of Virology, Norwegian Institute of Public Health, N-0213 Oslo, Norway
5. Institute of Clinical Medicine, University of Oslo, N-0318 Oslo, Norway
6. Department of Microbiology, Oslo University Hospital, N-0424 Oslo, Norway