1. Centre for Biotechnology Research and Development, Kenya Medical Research Institute, Nairobi, Kenya.
2. Center for Evolutionary and Theoretical Immunology, Parasitology Division, Museum of Southwestern Biology, Department of Biology, University of New Mexico, Albuquerque, New Mexico 87131.
3. Department of Basic Medical Sciences, Western University of Health Sciences, Lebanon, Oregon 97355.
4. School of Biological Sciences, College of Biological and Physical Sciences, University of Nairobi, Nairobi, Kenya.