aDepartment of Infectious Diseases, Perth Children's Hospital

bDepartment of Otolaryngology Head and Neck Surgery, Perth Children's Hospital

cDivision of Surgery, Medical School, University of Western, Australia

dWesfarmers Centre for Vaccines and Infectious Diseases, Telethon Kids Institute, Nedlands

eDivision of Paediatrics, School of Medicine, University of Western Australia, Perth, Australia

Correspondence to Dr Anita J. Campbell, (MBBS, DCH, DipPID, FRACP, PhD), Paediatric Infectious Diseases Specialist, Perth Children's Hospital, Department of Infectious Diseases, 15 Hospital Ave, Nedlands 6009, Western Australia, Australia. Tel: +618 6456 2222; fax: +618 6456 2071; e-mail: [email protected]