1. Koret School of Veterinary Medicine; The Hebrew University of Jerusalem; PO Box 12 Rehovot Israel 76100
2. Department of Avian Diseases; Kimron Veterinary Institute; PO Box 12 Bet Dagan Israel 50250
3. Department of Diagnostic Virology; Kimron Veterinary Institute; PO Box 12 Bet Dagan Israel 50250