[1] UNIV COLL & MIDDLESEX SCH MED,DEPT MED MICROBIOL,LONDON W1P 6DB,ENGLAND
[2] UNIV LONDON KINGS COLL,DULWICH HOSP,SCH MED & DENT,PUBL HLTH LAB,LONDON SE22 8QF,ENGLAND
[3] CENT PUBL HLTH LAB,DIV VIRUS REFERENCE,LONDON NW9 5HT,ENGLAND
[4] CENT MIDDLESEX HOSP NHS TRUST,PUBL HLTH LAB,LONDON NW10 7NS,ENGLAND