[1] Hlth Protect Agcy, Ctr Infect, Enter Virus Unit, Virus Reference Dept, London NW9 5HT, England
[2] Newcastle Gen Hosp, Primary Immunodeficiency Unit, Newcastle Upon Tyne NE4 6BE, Tyne & Wear, England
[3] Hlth Protect Agcy, Newcastle Lab, Newcastle Upon Tyne, Tyne & Wear, England
[4] Royal Victoria Infirm, Newcastle Upon Tyne NE1 4LP, Tyne & Wear, England
[5] Hlth Protect Agcy Yorkshire & Humber, Leeds Lab, Leeds, W Yorkshire, England