[1] So Iron Disorders Ctr, Birmingham, AL 35209 USA
[2] Univ Alabama, Dept Microbiol, Birmingham, AL 35294 USA
[3] Univ Alabama, Dept Med, Birmingham, AL 35294 USA
[4] Univ Alabama, Dept Epidemiol & Int Hlth, Birmingham, AL 35294 USA
[5] Howard Univ, Div Hematol Oncol, Washington, DC 20059 USA
[6] Howard Univ, Ctr Sickle Cell Dis, Washington, DC 20059 USA
[7] Univ Western Ontario, Dept Epidemiol & Biostat, London, ON N6A 5C1, Canada
[8] Wake Forest Univ, Bowman Gray Sch Med, Dept Publ Hlth Sci, Biostat Sect, Winston Salem, NC 27157 USA
[9] Univ Minnesota, Dept Lab Med & Pathol, Minneapolis, MN 55455 USA
[10] Oregon Hlth & Sci Univ, Dept Pathol, Portland, OR 97201 USA
[11] London Hlth Sci Ctr, Dept Med, Div Gastroenterol, London, ON N6A 2E8, Canada
[12] VA Long Beach Healthcare Syst, Long Beach, CA 90822 USA
[13] Univ Calif Irvine, Div Hematol Oncol, Irvine, CA 90822 USA
[14] Univ Calif Irvine, Dept Med, Div Epidemiol, Irvine, CA 92697 USA