[1] Univ Utah, Sch Med, Dept Pediat, Salt Lake City, UT USA
[2] Intermt Hlth Care, Pediat Clin Program, Salt Lake City, UT USA
[3] Primary Childrens Med Ctr, Dept Microbiol, Salt Lake City, UT USA
[4] Univ Utah, Sch Med, Dept Pathol, Salt Lake City, UT USA