{{Short description|Disease caused by Duck enteritis virus}} {{Virusbox | name = Duck enteritis virus | image = Duck plague victim.JPG | image_alt = Blood-stained ice from the nasal discharge of a mallard dying from duck plague | image_caption = Blood-stained ice from the nasal discharge of a mallard dying from duck plague | parent = Mardivirus | species = Mardivirus anatidalpha1 | synonyms = * Anatid alphaherpesvirus 1 * Anatid herpesvirus 1<ref name="2015.010aD">{{cite web |last1=Davison |first1=Andrew |title=Rename species in the family ''Herpesviridae'' to incorporate a subfamily designation |url=https://ictv.global/ictv/proposals/2015.010aD.A.v2.Herpesvirales_spren.pdf |website=International Committee on Taxonomy of Viruses (ICTV) |access-date=7 May 2019 |page=2 |language=en |date=27 January 2016 |quote=Subfamily Genus Current species name Proposed species name ''Alphaherpesvirinae'' ''Mardivirus'' ''Anatid herpesvirus 1'' ''Anatid alphaherpesvirus 1''}}</ref> *Duck enteritis virus<ref name="Others">{{cite web |title=ICTV 9th Report (2011) Other related viruses |url=https://talk.ictvonline.org/ictv-reports/ictv_9th_report/dsdna-viruses-2011/w/dsdna_viruses/301/other-related-viruses |archive-url=https://web.archive.org/web/20181222034221/https://talk.ictvonline.org/ictv-reports/ictv_9th_report/dsdna-viruses-2011/w/dsdna_viruses/301/other-related-viruses |url-status=dead |archive-date=December 22, 2018 |website=International Committee on Taxonomy of Viruses (ICTV) |access-date=7 May 2019 |language=en |date=2011 |quote=''Anatid herpesvirus 1'' (AnHV-1) (Duck enteritis virus) (Duck plague virus) [EU082088 = NC_013036]}}</ref> *Duck plague virus<ref name="Others"/> | synonyms_ref = | subdivision_ranks = | subdivision = }}
'''Duck plague''' (also known as '''duck viral enteritis''') is a worldwide disease caused by '''Duck enteritis virus''' (DEV) of the family ''Herpesviridae'' that causes acute disease with high mortality rates in flocks of ducks, geese, and swans. It is spread both vertically and horizontally—through contaminated water and direct contact. Migratory waterfowl are a major factor in the spread of this disease as they are often asymptomatic carriers of disease. The incubation period is three to seven days.<ref name=Fenner_1993>{{cite book|author1=Fenner, Frank J. |author2=Gibbs, E. Paul J. |author3=Murphy, Frederick A. |author4=Rott, Rudolph |author5=Studdert, Michael J. |author6=White, David O. |title=Veterinary Virology (2nd ed.)|publisher=Academic Press, Inc|year=1993|isbn=978-0-12-253056-2}}</ref> Birds as young as one week old can be infected.<ref name=":1" /> DEV is not zoonotic.
==Clinical signs and diagnosis== Upon exposure to DEV there is a 3-7 day for domestic fowl and up to a 14 day for wildfowl incubation period for the onset of symptoms.<ref name=":2">{{Cite book|title=Fenner's veterinary virology.|date=2011|publisher=Elsevier Academic Press|editor-last1=Maclachlan|editor-first1=N. James|editor-last2=Dubovi|editor-first2=Edward J.|isbn=978-0123751584|edition=4th|location=Amsterdam|oclc=690641300}}</ref> Sudden and persistent increases in flock mortality is often the first observation of DEV. Symptoms in individual birds include loss of appetite, decreased egg production (nearing 20-40% decreases), nasal discharge, increased thirst, diarrhea, ataxia, tremors, a drooped-wing appearance, and in males a prolapsed penis.<ref name=":2" /> Mortality rates for DEV may reach 90 percent.<ref name=Carter>{{cite web|author1=Carter, G.R. |author2=Flores, E.F. |author3=Wise, D.J. |year=2006|title=Herpesviridae|work=A Concise Review of Veterinary Virology| url=http://www.ivis.org/advances/Carter/Part2Chap11/chapter.asp?LA=1|access-date=2006-06-10}}</ref> Death usually occurs within 5 days after onset of symptoms.<ref name=":1" /> The clinical signs of DEV "vary with virulence of virus strain, species, sex, and immune system status" of the host.<ref name=":0" />
Due to the formation of diphtheroid plaques on the eyelids and the mucosae of the respiratory system and gastrointestinal system the bird may show ophthalmic signs and refuse to drink.
[[File:Blue-winged Teal.jpg|thumb|The Blue winged teal is one of the most susceptible species to DEV.]]
Duck enteritis virus can only infect birds of the family Anatidae of the order Anseriformes, with the possible exception of coots. A study of lesions found in "coots (order ''Gruiformes'')" found similarities to DEV lesions. This could be evidence that DEV is able to "cross to different orders and families" or "adapted to new hosts."<ref>{{Cite journal|last1=Salguero|first1=Francisco J.|last2=Sánchez-Cordón|first2=Pedro J.|last3=Núñez|first3=Alejandro|last4=Gómez-Villamandos|first4=José C.|date=2002-04-01|title=Histopathological and ultrastructural changes associated with herpesvirus infection in waterfowl|journal=Avian Pathology|volume=31|issue=2|pages=133–140|doi=10.1080/03079450120118612|issn=0307-9457|pmid=12396357|doi-access=free}}</ref> Waterfowl species have differing susceptibility to DEV, with wild fowl tending to be more resistant. Nonwaterfowl have not been shown to be infected by duck plague.<ref name=":0" /> Blue-winged teal have been found to be one of the most susceptible species and mallards one of the least.<ref name=":0" /> In another it took 300,000 more virus material to infect northern pintail than to infect blue-winged teal.<ref>{{Cite book|title=Field manual of wildlife diseases : general field procedures and diseases of birds|date=1999|publisher=U.S. Dept. of the Interior, U.S. Geological Survey|editor-last1=Friend|editor-first1=Milton|editor-last2=Franson|editor-first2=J. Christian|editor-last3=Ciganovich|editor-first3=Elizabeth A.|others=Redman, Phillip J.; Stenbeck, Rosemary S.|isbn=978-0607880960|location=Washington, D.C.|oclc=693130725}}</ref>
Diagnosis can usually be made based on the clinical signs and postmortem findings:
On post-mortem, petechial haemorrhage in the conjunctivae, mucous membranes, trachea, syrinx and intestine are pathognomonic for DEV. Diagnosis can also be confirmed with presence of virus inclusion bodies in tissues or a positive immunohistochemical staining for viral antigen.<ref name=":2" />
== Epidemiology == DEV is found during the spring seasons across the globe. The United States, Netherlands, and UK have the most occurrences from March to June. Whereas, Southern Hemisphere populations, such as in Brazil, are more likely to have outbreaks November through February during their spring season.<ref name=":0">{{Cite book|title=Infectious diseases of wild birds|last=Hansen|first=Wallace R.|publisher=Blackwell Publ|year=2007|isbn=978-0-8138-2812-1|editor-last=Thomas|editor-first=Nancy J.|location=Ames, Iowa|pages=87–107}}</ref>
If host organisms survive primary infection, they enter a latent stage lasting up to 4 years.<ref name=":0" /> Latent stage leads to vertical and horizontal transmission of DEV. Virus particles can be shed by the latent host in shared water or through direct contact (horizontal transmission), contributing to on-going epizootics.<ref name=":0" /> There is also evidence of vertical transmission from latent host carriers to their eggs and offspring, which will also be asymptomatic.<ref name=":0" /> However, during times of stress DEV may move to nerve roots from nerve ganglia and "induce herpetic lesions", a visible symptom of latency carrying.<ref name=":0" /> Environmental and physiological cues cause latent carriers to shed viral particles. Examples of physiological cues include "stress of migration, breeding season, [and] social interaction."<ref name=":0" /> Primary latency sites in carries are the trigeminal ganglion, lymphoid tissue, and blood lymphocytes. The latency sites of DEV is similar to other herpesviruses.<ref name=":1">{{Cite journal|last1=Dhama|first1=Kuldeep|last2=Kumar|first2=Naveen|last3=Saminathan|first3=Mani|last4=Tiwari|first4=Ruchi|last5=Karthik|first5=Kumaragurubaran|last6=Kumar|first6=M. Asok|last7=Palanivelu|first7=M.|last8=Shabbir|first8=Muhammad Zubair|last9=Malik|first9=Yashpal Singh|date=2017-01-01|title=Duck virus enteritis (duck plague) – a comprehensive update|journal=Veterinary Quarterly|volume=37|issue=1|pages=57–80|doi=10.1080/01652176.2017.1298885|issn=0165-2176|pmid=28320263|doi-access=free}}</ref>
==Treatment and control== Vaccination for duck viral enteritis is now routine in the United States.<ref name=Fenner_1993/> Only attenuated vaccines are efficacious. Once DEV is present, depopulation, relocation and intensive disinfection are required to overcome an outbreak. Solid natural immunity develops in recovered birds. There is no treatment for DEV, but resveratrol has shown to have some antiviral activity against the virus.<ref name=":1" />
Management practices such as preventing exposure to wild waterfowl and contaminated water and screening of new stock should be performed to prevent disease.
== Pathogenesis == DEV is considered pantropic because it is able to replicate and spread to multiple organs within the host.<ref name=":1" /> Viral replication causes an increase in vascular permeability, which leads to the lesions and hemorrhaging of organs, namely the liver, spleen, thymus, and bursa of Fabricius.<ref name=":1" /><ref name=":0" /> DVH-1 replicates in the mucous membranes of bird's esophagus and cloaca, the two primary entrances of the virus.<ref name=":0" /> The means of infection influences which tissues will be affected first and the incubation time before symptoms show.<ref name=":0" /> Typically viral replication begins in the digestive track and moves to bursa of Fabricuis, thymus, spleen, and liver.<ref name=":1" />
== Virology == === Classification === DEV is classified as the species ''Mardivirus anatidalpha1'' in the genus ''Mardivirus'', under the subfamily ''Alphaherpesvirinae'' of the family ''Herpesviridae'' in the order ''Herpesvirales''.<ref>{{cite web |title=Virus Taxonomy: 2023 Release |url=https://ictv.global/taxonomy |website=ictv.global |publisher=International Committee on Taxonomy of Viruses |date=30 October 2024 |access-date=29 January 2025}}</ref> Genomic evidence shows that DEV is genetically similar to Human alphaherpesvirus 1 and 2 (HSV-1 and HSV-2), Suid alphaherpesvirus 1, Equid alphaherpesvirus 1 and 4 (EHV-1 and EHV-4), and Bovine alphaherpesvirus 1 (BHV-1).<ref name=":3">{{Cite journal|last1=Liu|first1=Chaoyue|last2=Cheng|first2=Anchun|last3=Wang|first3=Mingshu|last4=Chen|first4=Shun|last5=Jia|first5=Renyong|last6=Zhu|first6=Dekang|last7=Liu|first7=Mafeng|last8=Sun|first8=Kunfeng|last9=Yang|first9=Qiao|date=2015-11-25|title=Duck enteritis virus UL54 is an IE protein primarily located in the nucleus|journal=Virology Journal|language=En|volume=12|issue=1|pages=198|doi=10.1186/s12985-015-0424-z|pmid=26606920|pmc=4658773|issn=1743-422X |doi-access=free }}</ref>
=== Genome === Duck enteritis virus, similar to other herpesviruses, has a linear double stranded DNA genome.<ref name=":2" /> The dsDNA weight is 119×10<sup>6</sup> daltons and approximately 158,091 base pairs long.<ref name=":4">{{Cite journal|last1=Li|first1=Yufeng|last2=Huang|first2=Bing|last3=Ma|first3=Xiuli|last4=Wu|first4=Jing|last5=Li|first5=Feng|last6=Ai|first6=Wu|last7=Song|first7=Minxun|last8=Yang|first8=Hanchun|title=Molecular characterization of the genome of duck enteritis virus|journal=Virology|volume=391|issue=2|pages=151–161|doi=10.1016/j.virol.2009.06.018|pmid=19595405|year=2009|doi-access=}}</ref> DEV has 67 genes in its genome, 65 of which are likely coding genes. Three of the genes have no homologs to other herpesviruses, and are unique to DEV. Unique long (UL), unique (US), unique short internal repeat (IRS), and unique short terminal repeat (TRS) regions make up the genome. The genomic arrangement is ordered as UL-IRS-US-TRS. There are 78 predicted proteins encoded by the genome.<ref name=":4" />
=== Structure === DEV has similar morphology to other ''Herpesvirales'' viruses.<ref>{{Cite journal|last1=Yuan|first1=Gui-ping|last2=Cheng|first2=An-chun|last3=Wang|first3=Ming-shu|last4=Liu|first4=Fei|last5=Han|first5=Xiao-ying|last6=Liao|first6=Yong-hong|last7=Xu|first7=Chao|date=2005-03-01|title=Electron Microscopic Studies of the Morphogenesis of Duck Enteritis Virus|journal=Avian Diseases|volume=49|issue=1|pages=50–55|doi=10.1637/7237-071004r|pmid=15839412|issn=0005-2086}}</ref> Common elements of herpesviruses include a "DNA core, icosahedral capsid, tegument, and envelope."<ref name=":2" /> The nucleocapsid of HPV-1 is 75 micrometers wide and the envelope diameter is 181 micrometers.<ref name=":0" />
=== Replication and transcription cycle === Three phases (immediate early (IE), early (E), and late (L)) of infection dictate the transcription of certain DEV genes. Immediate early begins after infection and before viral DNA replication.<ref name=":1" /> During this phase IE genes are transcribed without other proteins.<ref name=":3" /> The E genes are also transcribed before viral DNA replication, but are dependent on the IE gene products.<ref name=":3" /> After entering the host organism a virion begins the process of replication by first attaching to cells using glycoprotein spikes. gB, gC, gD, gH, and gL are known to be involved.<ref name=":1" /> Similar Alphaviruses use gC protein to aid in binding the virion to the cell and gD to stabilize it, if required.<ref name=":5">{{Cite journal|last1=Spear|first1=Patricia G.|last2=Eisenberg|first2=Roselyn J.|last3=Cohen|first3=Gary H.|title=Three Classes of Cell Surface Receptors for Alphaherpesvirus Entry|journal=Virology|volume=275|issue=1|pages=1–8|doi=10.1006/viro.2000.0529|pmid=11017782|year=2000|doi-access=free}}</ref> gB, gD, gH, and gL proteins allow for fusion of the cell and envelope, and are necessary for survival.<ref name=":3" />
Entrance to host cells begins infection, and is largely controlled by the US 2 viral protein.<ref name=":1" /> Envelope fusion with the plasma membrane of the host cell causes separation of the nucleocapsid from viral DNA and proteins.<ref name=":1" /> Multiple necessary viral proteins are located within the envelope.<ref name=":5" /> DNA and proteins enter the host cell nucleus and turn-off host cell synthesis of nucleic acids, proteins, and other macro molecules. There are two hypothesized origins of replication in the IRS and TRS regions of the genome.<ref name=":4" /><ref name=":1" /> Immature capsids are formed from coiled DNA.<ref name=":1" /> L genes are transcribed "after the synthesis of DNA and viral protein onset."<ref name=":3" /> Virion DNA maturation occurs as the nucleocapsids "bud through nuclear membrane."<ref name=":1" /> Completed viral replication occurs within 12 hours of infection. Vacuoles of mature virions are formed and released via exocytosis to other cells. Epithelial, lymphocytes, and macrophages are the favored sites of replication in the host organism.<ref name=":1" />
== History == The first report of a DEV outbreak was 1923 in the Netherlands.<ref name=":6">{{Cite book |title=Diseases of Poultry |date=2013|publisher=Wiley |editor=Swayne, David E. |editor2=Glisson, John R. |editor3=McDougald, Larry R. |editor4=Nolan, Lisa K. |editor5=Suarez, David L. |editor6=Nair, Venugopal |isbn=9781118719732 |edition=13th |location=Somerset |oclc=958568928}}</ref> Duck plague was first reported in the United States on Long Island, New York. The outbreak had economically devastating effects on the duck industry.<ref name=":1" /> The 1973 Lake Andes, South Dakota DEV outbreak was the other major incidence of the disease in the United States.<ref name=":6" /> The outbreak resulted in 43,000 deaths.<ref name=":1" /> In 2005 DEV was removed from the World Organisation for Animal Health (OIE) mandatory reporting list due to lack of evidence for international spread and minimal threat to public health.<ref>{{Cite web |url=http://www.oie.int/en/for-the-media/press-releases/detail/article/report-of-the-meeting-of-the-oie-terrestrial-animal-health-standards-commission-on-line/ |title=Report of the Meeting of the OIE Terrestrial Animal Health Standards Commission |date=January 17–28, 2005 |location=Paris}}</ref> However, there are economic concerns for regions depending on fowl industry, such as India.<ref name=":1" />
==References== {{Reflist}}
==External links== {{Wikispecies}} * {{Cite web | url=http://en.wikivet.net/Duck_Viral_Enteritis | title=Duck Viral Enteritis – WikiVet English}}, expert reviewed and published by Wikivet, accessed January 9, 2011
{{Herpesvirales}} {{Taxonbar|from=Q389123|from2=Q24808651}} {{Authority control}}
{{DEFAULTSORT:Duck Plague}} Category:Poultry diseases Category:Animal viral diseases Category:Alphaherpesvirinae Category:Animal vaccines