1. Department of Biotechnology, School of Medicine, Universidad de la República, Instituto de Higiene, Av. A. Navarro 3051, CP 11600, Montevideo, Uruguay
2. Department of Bacteriology and Virology, School of Medicine, Universidad de la República, Instituto de Higiene, Av. A. Navarro 3051, CP 11600, Montevideo, Uruguay
3. Department of Avian Pathology, Veterinary School, Universidad de la República, Montevideo, Uruguay
4. Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, United Kingdom