1. Department of Otolaryngology, Royal South Hants Hospital, Brintons Terrace, Southampton
2. HIV and STI Department, Health Protection Agency Centre for Infections, Colindale, London, NW9 5EQ;
3. Plymouth Hospitals NHS Trust Derriford Hospital, Plymouth;
4. Health Protection Agency Primary Care Unit, Microbiology Department, Gloucestershire Royal Hospital, Great Western Road, Gloucester, GL1 3NN