[1] French Natl Reference Ctr Meningococci, Inst Pasteur, F-75015 Paris, France
[2] Natl Reference Ctr Meningococci, Inst Hyg & Mikrobiol, Wurzburg, Germany
[3] Manchester Royal Infirm, Hlth Protect Agcy, Meningococcal Reference Unit, Manchester M13 9WL, Lancs, England