[1] Brown Univ, Sch Med, Dept Pediat, Pawtucket, RI 02860 USA
[2] Mem Hosp, Dept Pediat, Pawtucket, RI 02860 USA
[3] Brown Univ, Dept Mol Microbiol & Immunol, Div Biol & Med, Providence, RI 02912 USA
[4] Brown Univ, Sch Med, Dept Pathol & Lab Med, Providence, RI 02912 USA
[5] Rhode Isl Hosp, Dept Pathol & Lab Med, Providence, RI USA