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| {{CMG}} | | __NOTOC__ |
| | {{About1|Hepatitis D Virus}} |
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| {{EH}} | | '''For patient information click [[Hepatitis D(patient information)|here]]''' |
| | {{Hepatitis D}} |
| | {{CMG}}; {{AOEIC}} {{VK}}; {{JS}}; {{JM}} |
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| ==Overview==
| | {{SK}} Hepatitis delta virus; hepatitis D virus; HDV; Delta Hepatitis; HDV infection; Hep D; Hep d |
| {{DiseaseDisorder infobox | | | ==[[Hepatitis D overview|Overview]]== |
| Name = Hepatitis D|
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| MeshID = D003699
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| {{Taxobox
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| | virus_group = v
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| | genus = '''''Deltavirus'''''
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| | species = '''''Hepatitis delta virus'''''
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| }}
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| {{Search infobox}}
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| '''Hepatitis D''' is a [[disease]] caused by a small circular [[RNA virus]] ('''Hepatitis delta virus''' or '''hepatitis D virus''', '''HDV'''). HDV is considered to be a [[Satellite (biology)|subviral satellite]] because it can propagate only in the presence of another virus, the [[Hepatitis B|hepatitis B virus (HBV)]]. Transmission of HDV can occur either via simultaneous infection with HBV ([[coinfection]]) or via infection of an individual previously infected with HBV ([[superinfection]]). Both superinfection and coinfection with HDV results in more severe complications compared to infection with HBV alone. These complications include a greater likelihood of experiencing liver failure in acute infections and a greater likelihood of developing liver cancer in chronic infections. In combination with hepatitis B virus, hepatitis D has the highest mortality rate of all the hepatitis infections of 20%.
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| == Genome structure and similarities to viroids ==
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| The HDV genome exists as a negative sense, single-stranded, closed circular [[RNA]]. Because of a nucleotide sequence that is 70% self-complementary, the HDV genome forms a partially double stranded RNA structure that is described as rod-like. With a genome of approximately 1700 nucleotides, HDV is the smallest "virus" known to infect animals. However, it has been proposed that HDV may have originated from a class of plant viruses called [[viroids]]. Evidence in support of this hypothesis stems from the fact that both HDV and viroids exist as single-stranded, closed circular [[RNA]]s that have rod-like structures. Likewise, both HDV and viroids contain [[RNA]] sequences that can assume catalytically active structures called [[ribozyme]]s. During viral replication, these catalytic [[RNA]]s are required in order to produce unit length copies of the genome from longer [[RNA]] concatamers. Finally, neither HDV nor viroids encode their own polymerase. Instead, replication of HDV and viroids requires a host polymerase that can utilize [[RNA]] as a template. Based on indirect evidence, [[RNA]] polymerase II has been implicated in the replication of HDV. Normally [[RNA]] polymerase II utilizes [[DNA]] as a template and produces [[mRNA]]. Consequently, if HDV indeed utilizes [[RNA]] polymerase II during replication, it would be the only known pathogen capable of converting a [[DNA]] dependent polymerase into an [[RNA]] dependent polymerase.
| | ==[[Hepatitis D historical perspective|Historical Perspective]]== |
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| [[Image:Liver 1.jpg|thumbnail|center|400px|[[cirrhosis|Cirrhosis of the liver]] and [[hepatocellular carcinoma|liver cancer]] may ensue from Hepatitis D.]] | | ==[[Hepatitis D pathophysiology|Pathophysiology]]== |
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| == The Delta Antigens == | | ==[[Hepatitis D causes|Causes]]== |
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| A significant difference between viroids and HDV is that, while viroids produce no proteins, HDV produces two proteins called the small and large delta antigens (HDAg-S and HDAg-L, respectively). These two proteins are produced from a single open reading frame. They are identical for 195 amino acids and differ only by the presence of an additional 19 amino acids at the C-terminus of HDAg-L. Despite having 90% identical sequences, these two proteins play diverging roles during the course of an infection. HDAg-S is produced in the early stages of an infection and is required for viral replication. HDAg-L, in contrast, is produced during the later stages of an infection, acts as an inhibitor of viral replication, and is required for assembly of viral particles.
| | ==[[Hepatitis D differential diagnosis|Differentiating Hepatitis D from other Diseases]]== |
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| == Risk Factors == | | ==[[Hepatitis D epidemiology and demographics|Epidemiology and Demographics]]== |
| *Injection drug users
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| *Men who have sex with men
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| *Hemodialysis patients
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| *Sex contacts of infected persons
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| Health care and public safety workers
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| Infants born to infected mothers (very rare) [http://www.cdc.gov/ncidod/diseases/hepatitis/d/fact.htm]
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| == Pathophysiology & Etiology== | | ==[[Hepatitis D risk factors|Risk Factors]]== |
| Hepatitis D is a liver disease caused by the hepatitis D virus (HDV), a defective virus that needs the hepatitis B virus to exist. Hepatitis D virus (HDV) is found in the blood of persons infected with the virus.
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| *Occurs when blood from an infected person enters the body of a person who is not immune. | | ==[[Hepatitis D screening|Screening]]== |
| *HBV is spread through having sex with an infected person without using a condom (the efficacy of latex condoms in preventing infection with HBV is unknown, but their proper use may reduce transmission); | | |
| *By sharing drugs, needles, or "works" when "shooting" drugs; | | ==[[Hepatitis D natural history|Natural History, Complications and Prognosis]]== |
| *Through needlesticks or sharps exposures on the job; or | | |
| *From an infected mother to her baby during birth.[http://www.cdc.gov/ncidod/diseases/hepatitis/] [http://www.cdc.gov/ncidod/diseases/hepatitis/d/fact.htm] | | ==Diagnosis== |
| | [[Hepatitis D history and symptoms|History and Symptoms]] | [[Hepatitis D physical examination|Physical Examination]] | [[Hepatitis D laboratory findings|Laboratory Findings]] | [[Hepatitis D CT|CT]] | [[Hepatitis D MRI|MRI]] | [[Hepatitis D ultrasound|Ultrasound]] | [[Hepatitis D other diagnostic studies|Other Diagnostic Studies]] |
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| | ==Treatment== |
| | [[Hepatitis D medical therapy|Medical Therapy]] | [[Hepatitis D surgery|Surgery]] | [[Hepatitis D prevention|Prevention]] | [[Hepatitis D cost-effectiveness of therapy|Cost-Effectiveness of Therapy]] | [[Hepatitis D future or investigational therapies|Future or Investigational Therapies]] |
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| | ==Related Chapters== |
| | * [[Hepatitis A]] |
| | * [[Hepatitis B]] |
| | * [[Hepatitis C]] |
| | * [[Hepatitis E]] |
| | * [[Hepatitis F]] |
| | * [[Hepatitis G]] |
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| ==External links== | | ==External links== |
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| {{SIB}}
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| {{viruses}} | | {{viruses}} |
| | {{WH}} |
| | {{WS}} |
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| [[Category:Hepatitis|D]] | | [[Category:Hepatitis|D]] |
| [[Category:Viruses]] | | [[Category:Viruses]] |
| | | [[Category:Mature chapter]] |
| [[de:Hepatitis D]] | | [[Category:Disease]] |
| [[es:Hepatitis D]] | | [[Category:Gastroenterology]] |
| [[it:Epatite virale D]] | | [[Category:Emergency mdicine]] |
| [[ja:D型肝炎]] | | [[Category:Up-To-Date]] |
| [[pl:Wirus zapalenia wątroby typu D]] | | [[Category:Infectious disease]] |
| [[ru:Гепатит D]] | | [[Category:Hepatology]] |
| [[zh:丁型肝炎]] | |
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| {{WH}}
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| {{WS}}
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