Duck hepatitis virus

DHV-I, DHV-Ia, DHV-II DHV-III, and DHBV
Virus classification
Group:	Group IV ((+)ssRNA)
Family:	Picornaviridae, Hepadnaviridae (DHBV)
Genus:	Enterovirus
Species:	Duck Hepatitis Virus I, Ia, II, III, and Duck Hepatitis B Virus

Introduction

Duck hepatitis is caused by the enteroviruses DHV-1 and DHV-3. It is a fatal disease of ducklings causing opisthotonus and hepatitis. DHV-1 is found worldwide and causes disease in young ducklings, usually <6 weeks of age and spreads rapidly within a flock. It is the most virulent of the DHV species. DHV-3 has only been reported in the USA.

Causing acute and fatal disease in ducklings, duck hepatitis virus, DHV-1, is a Picornavirus that is distributed all over the world having significant impact on the poultry industry. First being recorded in 1949 in Long Island, New York, it was not until 57 years later in 2006 that the full genome of the pathogen was determined. This genome is composed of 7691 nucleotides and encodes and polyprotein of 2250 amino acids ^[1].

Duck hepatitis virus, DHV, type 1 (DHV-1), type 1a (DHV-1a), type 2 (DHV-2), and type 3 (DHV-3) are the four types of viruses that can cause disease in ducks. The pathology and pathogenicity between duck hepatitis virus type 1 and type 1a is, in essense, the same as one another ^[2].

Duck Hepatitis is a Class B disease listed by the Office des International Epizooties. The disease is not considered a zoonosis.

Duck hepatitis B virus, or DHBV, is a part of the Hepadnaviridae family that also comprises human Hepatitis B virus and Woodchuck hepatitis virus. It is vastly found among the wild and domestic duck population due to being passed on in utero. Duck hepatitis B virus is the first of its kind to utilize an avian host where it is found in the bloodstream of an egg laying duck. The virus is pass on from the infected duck to the egg resulting in congenital infection ^[3]. Ducks that are infected in utero are susceptible to developing hematomas or secondary amyloidosis. Since DHBV shares the same family as the contagious human form of the Hepatitis B virus, it is used for study as a safe alternative ^[4]. Hepadnaviruses can cause both acute and chronic liver diseases in ducks ^[5].

Classifications

Duck hepatitis virus type 1 is classified as an enterovirus, DHV-2 is an astrovirus, and DHV-3 as a picornavirus. DHV-1 has the most significant effect on the economy due to its high mortality rate when the spread is not controlled on all duck-growing farms. The virion of DHV-1 is a 20-40 nm diameter, non-enveloped, icosahedral particle that is resistant to ether and chloroform as well as possesses the ability to survive under normal environmental conditions for an extended amount of time ^[6].

Clinical Signs & Diagnosis

Clinical signs include sudden death, opisthotonus, paresis, paralysis and enophthalmos. DHV-1 infection is most virulent, with death occurring within 1–2 hours of clinical signs.

A preliminary diagnosis may be made based on the clinical signs and post-mortem examination. Autopsy should show an enlarged liver, which appears greenish and displays distinct ecchymotic haemorrhages. Inoculation, and direct immunofluorescence can be used to definitively diagnose DHV-1.

Treatment & Control

No treatment is effective once infected.

To prevent the disease, vaccination (ATCvet code QI01) is commercially available against DHV-1 and immunisation involves two or three inoculations. Additionally, DHV-1 can be prevented by strict isolation in the first 4–5 weeks of life. 5% phenol and formaldehyde can be used to inactivate the viruses in the environment.

References

1. ^ Liu, G., Yanguez, E., & Chen, Z. L. (2011). The duck hepatitis virus 5’-UTR possesses HCVlike IRES activity that is independent of eIF4F complex and modulated by downstream coding sequences. Virology Journal , 8 (147), 1-11
2. ^ Kim, M.-C., Kwon, Y.-K., Joh, S.-J., Kwon, J.-H., & Lindberg, A. M. (2008). Differential diagnosis between type-specific duck hepatitis virus type 1 (DHV-1) and recent Korean DHV-1-like isolates using a multiplex polymerase chain reaction. Avian Pathology , 37 (2), 171-177
3. ^ Wang, C.-Y. J., Giambrone, J. J., & Smith, B. F. (2002). Detection of Duck Hepatitis B Virus DNA on Filter Paper by PCR and SYBR Green Dye-Based Quantitative PCR. Journal of Clinical Microbiology , 40 (7), 2584-2590.
4. ^ Wang, C.-Y. J., Giambrone, J. J., & Smith, B. F. (2002). Detection of Duck Hepatitis B Virus DNA on Filter Paper by PCR and SYBR Green Dye-Based Quantitative PCR. Journal of Clinical Microbiology , 40 (7), 2584-2590.
5. ^ Pugh, J. C., Yaginuma, K., Koike, K., & Summers, J. (1988). Duck Hepatitis B Virus (DHBV) Particles Produced by Transient Expression of DHBV DNA in a Human Hepatoma Cell Line Are Infectious In Vitro. Journal of Virology , 62 (9), 3513-3516
6. ^ Kim, M.-C., Kwon, Y.-K., Joh, S.-J., Michael, L. A., Kwon, J.-H., & Kim, J.-H. K.-J. (2006). Molecular analysis of duck hepatitis virus type 1 reveals a novel lineage close to the genus Parechovirus in the family Picornaviridae. Journal of General Virology , 87, 3307-3316

• Duck Hepatitis Virus, expert reviewed and published by Wikivet at http://en.wikivet.net/Duck_Hepatitis_Virus, accessed 01/09/2011

This veterinary medicine–related article is a stub. You can help Wikipedia by expanding it.v · Categories: Poultry diseases Animal virology Virus stubs Veterinary medicine stubs Wikimedia Foundation. 2010. Игры ⚽ Поможем написать курсовую Duck decoy (structure) Lemnoideae Look at other dictionaries: Duck hepatitis B virus — Virus classification Group: Group VII (dsDNA RT) Order: Unassigned Family …   Wikipedia duck hepatitis B virus — a virus of the genus Avihepadnavirus that causes duck virus hepatitis …   Medical dictionary virus — viruslike, adj. /vuy reuhs/, n., pl. viruses. 1. an ultramicroscopic (20 to 300 nm in diameter), metabolically inert, infectious agent that replicates only within the cells of living hosts, mainly bacteria, plants, and animals: composed of an RNA …   Universalium Hepatitis B — Classification and external resources Electron micrograph of hepatitis B virus ICD 10 B …   Wikipedia Virus — A microorganism smaller than a bacteria, which cannot grow or reproduce apart from a living cell. A virus invades living cells and uses their chemical machinery to keep itself alive and to replicate itself. It may reproduce with fidelity or with… …   Medical dictionary Hepatitis B virus — For the disease, see Hepatitis B. Hepatitis B virus TEM micrograph showing hepatitis B viruses Virus classification Group …   Wikipedia duck virus hepatitis vaccine — a modified live virus vaccine of chick embryo origin, used for prevention of duck virus hepatitis …   Medical dictionary duck virus hepatitis yolk antibody — yolk antibody derived from chicken eggs, used for treatment of duck virus hepatitis …   Medical dictionary duck virus hepatitis — a highly fatal, rapidly spreading disease of waterfowl ducklings, caused by a virus of the genus Avihepadnavirus, characterized primarily by hepatitis marked by an enlarged, mottled, hemorrhagic liver …   Medical dictionary Duck HBV RNA encapsidation signal epsilon — The Duck HBV RNA encapsidation signal epsilon is an RNA structure that is shown to facilitate encapsidation of the pregenomic RNA required for replication.DHBV is used as a model to understand human HBV. DHBV epsilon consists of a stem structure …   Wikipedia 18+ © Academic, 2000-2024 Contact us: Technical Support, Advertising Dictionaries export, created on PHP, Joomla, Drupal, WordPress, MODx. Mark and share Search through all dictionaries Translate… Search Internet Share the article and excerpts Direct link … Do a right-click on the link above and select “Copy Link”