Turkey hemorrhagic enteritis virus 41678 Experimental or natural exposure to HEV in turkeys often leads to HE and splenomegaly. The intestinal lesion, appearing within 5-6 days of oral exposure to virulent HEV, is often characterized by grossly visible accumulation of blood in the duodenum and jejunum. Along with the intestinal lesion, the spleen may become grossly enlarged and mottled. Histologically, severe intestinal hemorrhages may be associated with necrosis of the tips of villi and a varying degree of lymphoid cell hyperplasia in the lamina propria. The spleen lesion is characterized by lymphoid cell necrosis, reticular cell hyperplasia and the appearance of intranuclear inclusion bodies. Histopathological changes may also be present in a number of other organs including liver, lungs, pancreas, bursa of Fabricius and thymus (Sharma, 1991). Hemorrhagic enteritis Turkeys are afflicted by hemorrhagic enteritis, and chickens have been found to have antibodies to the virus (Sharma, 1991). Hemorrhagic enteritis (HE), an economically important disease of turkeys is caused by an adenovirus. The virus is ubiquitous and is liable to infect most field turkeys. In unprotected turkey flocks, infection with virulent hemorrhagic enteritis virus (HEV) may result in variable mortality and immunodepression. Turkeys younger than 2-4 weeks of age are resistant to clinical HE. This age-related resistance is expressed in the presence or absence of maternal antibodies against HEV. Clinical disease is characterized by HE and splenomegaly. The virus causes intranuclear inclusions in the reticuloendothelial cells. Bursectomy or splenectomy abrogate clinical HE. Field data and laboratory studies indicate that HEV causes immunodepression in the humoral as well as the cellular immune functions of turkeys. The mechanism of immunodepression is not known (Sharma, 1991). Baboon Papio cynocephalus 9556 Bank vole Clethrionomys glareolus 447135 Bear Ursus americanus 9643 Birds Passeroidea 175121 Brown Trout Salmo trutta 8032 Buffalo Bison bison 9901 Carnivores Vulpes 9625 Cat Felis catus 9685 Catfishes Siluriformes 7995 Cattle Bos taurus 9913 Chicken Gallus gallus 9031 Chimpanzee Pan troglodytes 9598 chinchillas Chinchillidae 10150 Copper Pheasant Syrmaticus soemmerringii 9067 Deer Cervus elaphus 9860 Deer mouse Peromyscus maniculatus 10042 Dog Canis familiaris 9615 Ducks Anas 8835 Ferret Mustela putorius furo 9669 Fish Hyperotreti 117565 Gerbil Gerbillina 10045 Goat Capra hircus 9925 Gray wolf Canis lupus 9612 Guinea pig Cavia porcellus 10141 Hamster Mesocricetus auratus 10036 Horse Equus caballus 9796 Human Homo sapiens 9606 Macaque Macaca fascicularis 9541 Mongolian Gerbil Meriones unguiculatus 10047 Monkey Platyrrhini 9479 Mouse Mus musculus 10090 None None Parrot Psittacidae 9224 Pig Sus scrofa 9823 Rabbit Oryctolagus cuniculus 9986 Rainbow trout Oncorhynchus mykiss 8022 Rat Rattus 10114 Raven Corvus corax 56781 sei whale Balaenoptera borealis 9768 Sheep Ovis aries 9940 Squirrel Spermophilus richardsonii 37591 Tree shrew Tupaiidae 9393 Trouts, salmons & chars Salmoninae 504568 Turkey Meleagris gallopavo 9103 Vole Microtus ochrogaster 79684 Water buffalo Bubalus bubalis 391902 Hemorrhagic Enteritis Live Virus Vaccine (USDA: 17E1.20) Intervet Inc., Arko Laboratories Ltd., Brinton Laboratories Inc., Biomune Company VO_0001824 Licensed USA Sharma, 1991 journal Sharma JM 1991 30 1 67-71 Veterinary immunology and immunopathology