1. School of Life Sciences, University of Warwick, Coventry, CV4 7AL
2. Cranfield Health, Cranfield University, Cranfield, Bedfordshire MK43 0AL, UK
3. School of Biological Sciences, University of Reading, Whiteknights, Reading, RG6 6AJ, UK
4. Unité des Virus Emergents, Faculté de Médecine Timone, 5ème étage Aile Bleu, 27, Bd Jean Moulin, 13385 Marseille, Cedex 05, France