1. Sir Charles Gairdner Hospital, Verdun StreetNedlands, WA 6009.
2. Health Department of Western AustraliaRoyal StreetEast Perth, WA 6004.
3. Townsville General Hospital, Townsville, QLD 4810; and Anton Breinl Centre for Tropical Health and Medicine, James Cook University of North Queensland, QLD 4811.