Affiliation: | a Department of Parasitology and Animal Diseases, Veterinary Research Division, National Research Centre, P.O. Box 12622, 33 El-Tahrir Street, Dokki, Giza, Egypt b Veterinary Serum and Vaccine Research Institute, P.O. Box 131, El-Sekka Elbeda Street, 11381 Abbassia, Cairo, Egypt c Fish Medicine and Livestock Management, University of Veterinary Medicine, Veterinaerplatz 1, 1210 Vienna, Austria |