[1] Univ Maryland, Sch Med, Ctr Vaccine Dev, Baltimore, MD 21201 USA
[2] Univ Maryland, Sch Med, Dept Pediat, Baltimore, MD 21201 USA
[3] Resp & Enter Viruses Branch, Viral Gastroenteritis Sect, Atlanta, GA USA
[4] Natl Ctr Infect Dis, Off Director, Div Viral & Rickettsial Dis, Oakland, CA USA
[5] Ctr Dis Control & Prevent, Epidem Intelligence Serv, Epidemiol Program Off, Publ Hlth Serv,US Dept Hlth & Human Serv, Atlanta, GA USA
[6] Kaiser Permanente Med Care Program, Oakland, CA USA
[7] New York State Dept Hlth, Albany, NY USA