1. Wellcome Centre for the Epidemiology of Infectious Disease, Department of Zoology, University of Oxford, Oxford UKOX1 3PS, UK
2. Florida Medical Entomology Laboratory, University of Florida, 200 9th Street SE,Vero Beach, FL 32962, USA
3. Onderstepoort Veterinary Institute, Onderstepoort 0110, Republic of South Africa
4. ODA Insect Pest Management Initiative, Box CY52, Causeway, Harare, Zimbabwe
5. MRCTrypanosomiasis Research Group,Department of ClinicalVeterinary Science,University of Bristol, Langford, Bristol BS18 7DU, UK
6. Walter & ElizaHall Institute ofMedical Research, Parkville,Victoria 3050, Australia
7. Centre for Tropical Veterinary Medicine,University of Edinburgh, Easter Bush, Roslin,Midlothian EH25 9RG, UK