1. Department of Epidemiology and International Health, School of Public Health, University of Alabama at Birmingham, Birmingham, Alabama 35294
2. Tropical Disease Research Center, Ndola, Zambia
3. Division of Hematology and Oncology, Department of Medicine, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama 35294
4. Zambia National Blood Transfusion Service, Lusaka, Zambia
5. Virology and Immunology Laboratory, University Teaching Hospital, Lusaka, Zambia.
6. Department of Epidemiology and International Health, School of Public Health, University of Alabama at Birmingham, Birmingham, Alabama 35294; Department of Geographic Medicine, Department of Medicine, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama 35294; Department of Pediatrics, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama 35294
7. Department of Pediatrics, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama 35294; Department of Microbiology, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama 35294.