1. Center for Health Disparities Research, Brody School of Medicine, East Carolina University, 1800 W. 5th Street (Medical Pavilon), Greenville, NC 27834 USA.
2. Department of Public Health, 1709 W. 6th Street, Mail Stop 660, Brody School of Medicine, East Carolina University, Greenville, NC 27834, USA.
3. Department of Molecular virology, Immunology and Medical Genetics, 998 Biomedical Research Tower, 460 W. 12th Avenue, The Ohio State University, Columbus, OH 43210, USA.
4. Department of Defence Center for Deployment Health Research, Naval Health Research Center, Dept. 164, 140 Sylvester Rd., San Diego, CA 92106, USA.