1. School of Public Health, University of Zambia, Box 50110, Lusaka, Zambia
2. Chainama College of Health Sciences, Box 33991, Lusaka, Zambia
3. Centre for Infectious Diseases Research in Zambia, Box 3481, Lusaka, Zambia
4. Department of Biostatistics, School of Public Health, University of Ghana, P.O. Box LG 25 Legon, Accra
5. National Food and Nutrition Commission, Lumumba Road, Box 32669, Lusaka, Zambia
6. Immunomedics Inc., 300, American Rd., Morris Plains, NJ, USA