[1] Bristol Royal Infirm & Gen Hosp, Milne Sexual Hlth Ctr, Dept Genitourinary Med, Bristol BS1 8HW, Avon, England
[2] Genitourinary Infect Reference Lab, Bristol, Avon, England
[3] Royal Cornwall Hosp, Dept Genitourinary Med, Truro, England
[4] Royal United Hosp, Dept Genitourinary Med, Bath BA1 3NG, Avon, England
[5] Univ Bristol, Bristol BS2 8AS, Avon, England