[1] Italian Natl Canc Inst Regina Elena, Dept Epidemiol, Rome, Italy
[2] WHO, CH-1211 Geneva, Switzerland
[3] Norwegian Knowledge Ctr Hlth Serv, Oslo, Norway
[4] James Cook Univ Hosp, Dept Infect & Travel Med, Middlesbrough, Cleveland, England
[5] Bond Univ, Fac Hlth Sci & Med, Gold Coast, Qld, Australia
[6] Univ Virginia, Hlth Sci Ctr, Dept Internal Med, Charlottesville, VA 22908 USA
[7] Univ Virginia, Hlth Sci Ctr, Dept Pathol, Charlottesville, VA USA
[8] Ctr Dis Control & Prevent, Influenza Div, Natl Ctr Immunizat & Resp Dis, Atlanta, GA USA
[9] Univ Oxford, Clin Res Unit, Hosp Trop Dis, Ho Chi Minh City, Vietnam
[10] Ctr Hosp Tourcoing, Serv Univ Maladies Infect, Fac Med Lille, Tourcoing, France
[11] NIH, Bethesda, MD 20892 USA
[12] Queen Sirikit Natl Inst Child Hlth, Minist Publ Hlth, Bangkok, Thailand
[13] Yuzuncu Yil Univ, Dept Pulm, Van, Turkey
[14] Keio Univ, Dept Pediat, Fac Med, Keiyu Hosp, Yokohama, Kanagawa 223, Japan