[1] Childrens Natl Med Ctr, Div Pediat Infect Dis, Washington, DC 20010 USA
[2] George Washington Univ, Sch Med, Dept Pediat, Washington, DC 20052 USA
[3] Childrens Natl Med Ctr, Div Lab Med, Washington, DC 20010 USA
[4] George Washington Univ, Sch Med, Dept Microbiol Immunol & Trop Med, Washington, DC USA
[5] George Washington Univ, Sch Med, Dept Pathol, Washington, DC USA