1. Medical Entomology and Zoonoses Ecology Group, Microbial Risk Assessment, Emergency Response Division, Health Protection Agency, Porton Down, Salisbury, United Kingdom.
2. Avia-GIS, Agro-Veterinary Information and Analysis, Zoersel, Belgium.
3. Institute of Parasitology, University of Zurich, Zurich, Switzerland.
4. Institute of Tropical Medicine, Antwerp, Belgium.
5. European Centre for Disease Prevention and Control, Stockholm, Sweden.