Duck hepatitis virus 1 691956 Duck virus hepatitis (DVH) A natural outbreak of DHV Type I has been reported in mallard ducklings; experimental DHV Type I infections have been produced in goslings, turkey poults, young pheasants, quail, and guinea fowl. The viruses that cause hepatitis in ducklings should not be confused with duck hepatitis B virus, a hepadnavirus infection of older ducks (Merck Vet Manual: Duck Viral Hepatitis). Duck viral hepatitis is an acute, highly contagious, viral disease of young ducklings characterized by a short incubation period, sudden onset, high mortality, and characteristic liver lesions. The disease is of economic importance in all duck-raising areas of the world. Three distinct types of duck hepatitis virus (DHV) have been isolated from diseased ducklings.The originally described, most widespread, and most virulent DHV Type I is an enterovirus in the family Picornaviridae and is readily propagated in chick and duck embryos. It does not produce hemagglutinins. Field experience with DHV Type I indicates that egg transmission does not occur. The disease can be transmitted experimentally by parenteral or oral administration of infected tissues. Viruses differing from classic DHV Type I have been recognized as causes of hepatitis in ducklings. DHV Type II is considered to be an astrovirus and is difficult to propagate under laboratory conditions; DHV Type III is a member of the Picornaviridae, is antigenically distinct from Type I virus, and can be propagated in duck (but not chick) embryos. A distinct serologic variant of DHV Type I, named DHV Type Ia, has also been described (Merck Vet Manual: Duck Viral Hepatitis). 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 Duck hepatitis virus 1 DNA vaccine pSCA/VP1 VO_0004575 DNA vaccine Research pSCA1 [Ref2703:Fu et al., 2012] Intramuscular injection (i.m.) Intramuscular injection (i.m.) DNA vaccine construction DHV-1-specific antibodies, neutralizing antibodies and lymphocyte proliferation were well induced in ducklings (Fu et al., 2012). VO_0003057 Vaccination with pSCA/VP1 could significantly reduce the onset and duration of viremia and decrease virus replication in ducklings (Fu et al., 2012). Duck Hepatitis Virus Vaccine rDEV-UL26/27-P13C Recombinant vector vaccine Research [Ref5574:Yang et al., 2021] DEV (Duck Enteritis Virus) Intramuscular injection (i.m.) (Yang et al., 2021)The P1-P2A-3C cassette was inserted into the gene junction between UL26 and UL27 in the DEV vaccine strain genome. For transfection, we used the modified fosmids, C144-UL26/27-P13C, which replaced the parental fosmid C144. After being blindly passaged once in CEFs, DEV-typical plaques appeared in the CEFs transfected with the DNA combinations. Electron microscopy confirmed the successful rescue of the recombinant viruses. Insertion of the P1-P2A-3C cassette at the proper site was confirmed by PCR and sequencing, using a forward primer specific to the P1 gene and a reverse primer matching the UL26 sequence. The recombinant DEV was designated rDEV-UL26/27-P13C, with the P1 and 3C genes inserted between UL26 and UL27, in the DEV genome. Intramuscular injection (i.m.) (Yang et al., 2021) P1, 3C (Yang et al., 2021) Groups of 20 ducks were inoculated with 1000 ELD50 of the recombinant viruses to evaluate the antibody responses against DHAV-3 and DEV induced by the recombinant DEVs. (Yang et al., 2021) All the animal experiments were performed using SPF ducks housed in filtered-air, negative-pressure isolation units. The ducks were given free access to food and water. To evaluate the protective efficacy of the recombinant viruses against challenge by the virulent DHAV-3 and DEV, each group of 20 ducks was inoculated subcutaneously with 1,000 times the 50% egg lethal dose (1000 ELD50) of the rescued viruses at 1 day of age. At 7 days post-vaccination, 10 ducks in each group were intramuscularly challenged with 100 ELD50 of the virulent DHAV-3 A3 strain, and the remaining 10 ducks were intramuscularly challenged with 1,000 minimum lethal doses of the virulent DEV CSC strain. Ten unvaccinated and unchallenged ducks were used as the healthy controls. The ducks were examined for clinical signs and mortality for 2 weeks after the challenge. The dead and surviving ducks were observed for gross lesions in the liver, spleen, kidneys, esophagus, intestine, thymus, and bursa. (Yang et al., 2021) The ducks were inoculated with the recombinant viruses at 1 day of age and challenged with the virulent DHAV-3 A3 strain 7 days post-inoculation for protective efficacy evaluation. These ducks did not show any clinical signs in response to vaccination before the challenge. The ducks in the rDEV-UL26/27-P13C vaccination group were completely protected from lethal DHAV-3 challenge, showing no clinical signs of disease and no visible lesions in the liver, spleen, or other organs during the 2-week observation period. However, all ducks in the challenge control group showed severe clinical signs from 2 days post-challenge, including depression, lethargy, and anorexia; all these ducks died from the DHAV-3 challenge within 3 days. As expected, the ducks in the healthy control group did not show any clinical signs during the experiment. These results indicate that rDEV-UL26/27-P13C induced 100% protection against lethal DHAV-3 challenge in ducks. Duck Hepatitis Virus Vaccine rDEV-US7/8-P13C Recombinant vector vaccine Research [Ref5574:Yang et al., 2021] DEV (Duck Enteritis Virus) Intramuscular injection (i.m.) A bivalent duck hepatitis virus recombinant vector vaccine that is made of a P1-P2a-33 cassette inserted between US7 and US8 of the viral genome (Yang et al., 2021). (Yang et al., 2021) The P1-P2A-3C cassette was inserted into the gene junction between US7 and US8 in the DEV vaccine strain genome. For transfection, we used the modified fosmid C343-US7/8-P13C, which replaced the parental fosmid C343. After being blindly passaged once in CEFs, DEV-typical plaques appeared in the CEFs transfected with the DNA combinations. Electron microscopy confirmed the successful rescue of the recombinant viruses. Insertion of the P1-P2A-3C cassette at the proper site was confirmed by PCR and sequencing, using a forward primer specific to the P1 gene and a reverse primer matching the US8 sequence. The recombinant DEVs was designated rDEV-US7/8-P13C, with the P1 and 3C genes inserted between US7 and US8, in the DEV genome. Intramuscular injection (i.m.) (Yang et al., 2021) P1, 3C (Yang et al., 2021) Groups of 20 ducks were inoculated with 1000 ELD50 of the recombinant viruses to evaluate the antibody responses against DHAV-3 and DEV induced by the recombinant DEVs. (Yang et al., 2021)All the animal experiments were performed using SPF ducks housed in filtered-air, negative-pressure isolation units. The ducks were given free access to food and water. To evaluate the protective efficacy of the recombinant viruses against challenge by the virulent DHAV-3 and DEV, each group of 20 ducks was inoculated subcutaneously with 1,000 times the 50% egg lethal dose (1000 ELD50) of the rescued viruses at 1 day of age. At 7 days post-vaccination, 10 ducks in each group were intramuscularly challenged with 100 ELD50 of the virulent DHAV-3 A3 strain, and the remaining 10 ducks were intramuscularly challenged with 1,000 minimum lethal doses of the virulent DEV CSC strain. Ten unvaccinated and unchallenged ducks were used as the healthy controls. The ducks were examined for clinical signs and mortality for 2 weeks after the challenge. The dead and surviving ducks were observed for gross lesions in the liver, spleen, kidneys, esophagus, intestine, thymus, and bursa. (Yang et al., 2021) The ducks were inoculated with the recombinant viruses at 1 day of age and challenged with the virulent DHAV-3 A3 strain 7 days post-inoculation for protective efficacy evaluation. These ducks did not show any clinical signs in response to vaccination before the challenge. The ducks in the rDEV-US7/8-P13C vaccination group were completely protected from lethal DHAV-3 challenge, showing no clinical signs of disease and no visible lesions in the liver, spleen, or other organs during the 2-week observation period. However, all ducks in the challenge control group showed severe clinical signs from 2 days post-challenge, including depression, lethargy, and anorexia; all these ducks died from the DHAV-3 challenge within 3 days. As expected, the ducks in the healthy control group did not show any clinical signs during the experiment. These results indicate that rDEV-US7/8-P13C induced 100% protection against lethal DHAV-3 challenge in ducks. Duck Virus Hepatitis Modified Live Virus Vaccine (USDA: 14B1.10) International Duck Research Cooperative, Inc. VO_0001738 Live, attenuated vaccine Licensed USA VP1 Duck hepatitis A virus strain ZJ serotype 1 129307224 1006061 ? VP1 protein 6.87 25110.8 303 vaccine strain; modified live virus >ABO30521.1 VP1 protein, partial [Duck hepatitis A virus 1] GDSNQLGDDEPVCFLNFETANVPIQGESHTLVKHLFGRQWLVRTVQHASTVQELDLQVPDRGHASLIRFF AYFSGEIILTIVNNGTTPAMVAHSYSMDDLSSEYAVTAMGGVMIPANSAKNIPVPFYSVTPLRPTRPIPG TSEATFGRLFMWTQSGSLSVFMGLKKPALFFPLPAPTSTTLSRGSNGVIPTLDQSGDEVDCHFCKICSKM KRMWKPKGHFRFCLRLKTLAFELDLEIE Protective antigen Fu et al., 2012 journal Fu Y, Chen Z, Li C, Liu G 2012 160 3-4 314-318 Veterinary microbiology Merck Vet Manual: Duck Viral Hepatitis website http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/202100.htm