[1] Natl Inst Publ Hlth & Environm, Res Lab Infect Dis, RIVM, NL-3720 BA Bilthoven, Netherlands
[2] Univ Amsterdam, Acad Med Ctr, Lab Med Microbiol, NL-1105 AZ Amsterdam, Netherlands
[3] Municipal Hlth Lab, Amsterdam, Netherlands
[4] N Manchester Gen Hosp, Dept Infect Dis, Manchester, Lancs, England
[5] Ctr Dis Control & Prevent, Resp & Enter Virus Branch, Ctr Infect Dis, Atlanta, GA USA