1. Department of Biostastics, Medical Education, University of Washington, Seattle, Washington 98195-7232.
2. Department of Biomedical Informatics, University of Washington, Seattle, Washington 98195-7232.
3. World Vision Latin American and the Caribbean Regional Office, Tegucigalpa, Honduras.
4. Department of Microbiology, National Autonomous University of Honduras, Tegucigalpa, Honduras.
5. Department of Microbiology, University of Washington, Seattle, Washington 98195-7232.