1. Department of Human Health, International Centre for Insect Physiology and Ecology, Nairobi, Kenya.
2. Department of Medical Virology, University of Pretoria, Pretoria, Sandringham, South Africa.
3. Ministry of Public Health and Sanitation, National Laboratory Surveillance and Response, Nairobi, Kenya.
4. U.S. Army Medical Research Unit, Nairobi, Kenya.
5. National Institute for Communicable Diseases, Pretoria, Sandringham, South Africa.