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| {{DiseaseDisorder infobox | | | __NOTOC__ |
| Name = Hepatitis D|
| | {{About1|Hepatitis D Virus}} |
| 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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| {{CMG}}
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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 |
| | ==[[Hepatitis D overview|Overview]]== |
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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%.
| | ==[[Hepatitis D historical perspective|Historical Perspective]]== |
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| ==Incidence== | | ==[[Hepatitis D pathophysiology|Pathophysiology]]== |
| HDV is rare in most [[developed country|developed countries]], and is mostly associated with [[Intravenous drug use (recreational)|intravenous drug abuse]]. However HDV is much more common in Mediterranean countries, sub-Saharan Africa, the Middle East, and countries in the northern part of South America.<ref>{{cite journal |author=Radjef N, Gordien E, Ivaniushina V, ''et al'' |title=Molecular phylogenetic analyses indicate a wide and ancient radiation of African hepatitis delta virus, suggesting a deltavirus genus of at least seven major clades |journal=J. Virol. |volume=78 |issue=5 |pages=2537–44 |year=2004 |month=March |pmid=14963156 |pmc=369207 |url=http://jvi.asm.org/cgi/pmidlookup?view=long&pmid=14963156 |doi=10.1128/JVI.78.5.2537-2544.2004}}</ref> In all, about 20 million people may be infected with HDV.<ref>{{cite journal |author=Taylor JM |title=Hepatitis delta virus |journal=Virology |volume=344 |issue=1 |pages=71–6 |year=2006 |month=January |pmid=16364738 |doi=10.1016/j.virol.2005.09.033}}</ref>
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| == Genome structure and similarities to viroids == | | ==[[Hepatitis D causes|Causes]]== |
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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.<ref>{{cite journal |author=Saldanha JA, Thomas HC, Monjardino JP |title=Cloning and sequencing of RNA of hepatitis delta virus isolated from human serum |journal=J. Gen. Virol. |volume=71 ( Pt 7) |issue= |pages=1603–6 |year=1990 |month=July |pmid=2374010 |url=http://vir.sgmjournals.org/cgi/pmidlookup?view=long&pmid=2374010 |doi=10.1099/0022-1317-71-7-1603}}</ref> With a genome of approximately 1700 nucleotides, HDV is the smallest "virus" known to infect animals.
| | ==[[Hepatitis D differential diagnosis|Differentiating Hepatitis D from other Diseases]]== |
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| It has been proposed that HDV may have originated from a class of plant viruses called [[viroids]].<ref>{{cite journal |author=Elena SF, Dopazo J, Flores R, Diener TO, Moya A |title=Phylogeny of viroids, viroidlike satellite RNAs, and the viroidlike domain of hepatitis delta virus RNA |journal=Proc. Natl. Acad. Sci. U.S.A. |volume=88 |issue=13 |pages=5631–4 |year=1991 |month=July |pmid=1712103 |pmc=51931 |url=http://www.pnas.org/cgi/pmidlookup?view=long&pmid=1712103 |doi=10.1073/pnas.88.13.5631}}</ref> Evidence in support of this hypothesis stems from the fact that both HDV and viroids exist as single-stranded, closed circular RNAs that have rod-like structures. Likewise, both HDV and viroids contain RNA sequences that can assume catalytically active structures called ribozymes. During viral replication, these catalytic RNAs 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.<ref>{{cite journal |author=Taylor JM |title=Replication of human hepatitis delta virus: recent developments |journal=Trends Microbiol. |volume=11 |issue=4 |pages=185–90 |year=2003 |month=April |pmid=12706997 |doi=10.1016/S0966-842X(03)00045-3}}</ref> RNA polymerase II has been implicated as the polymerase responsible for the replication of HDV.<ref>{{cite journal |author=Lehmann E, Brueckner F, Cramer P |title=Molecular basis of RNA-dependent RNA polymerase II activity |journal=Nature |volume=450 |issue=7168 |pages=445–9 |year=2007 |month=November |pmid=18004386 |doi=10.1038/nature06290}}</ref><ref>{{cite journal |author=Filipovska J, Konarska MM |title=Specific HDV RNA-templated transcription by pol II in vitro |journal=RNA |volume=6 |issue=1 |pages=41–54 |year=2000 |month=January |pmid=10668797 |pmc=1369892 |url=http://www.rnajournal.org/cgi/pmidlookup?view=long&pmid=10668797 |doi=10.1017/S1355838200991167}}</ref> 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 using a DNA-dependent polymerase as an RNA-dependent polymerase.
| | ==[[Hepatitis D epidemiology and demographics|Epidemiology and Demographics]]== |
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| == The Delta Antigens == | | ==[[Hepatitis D risk factors|Risk Factors]]== |
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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 screening|Screening]]== |
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| == Risk Factors == | | ==[[Hepatitis D natural history|Natural History, Complications and Prognosis]]== |
| *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== | | ==Diagnosis== |
| 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. | | [[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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| *Occurs when blood from an infected person enters the body of a person who is not immune.
| | ==Treatment== |
| *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);
| | [[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]] |
| *By sharing drugs, needles, or "works" when "shooting" drugs;
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| *Through needlesticks or sharps exposures on the job; or
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| *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]
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| ==References== | | ==Related Chapters== |
| {{reflist|2}}
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| == See also ==
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| * [[Hepatitis A]] | | * [[Hepatitis A]] |
| * [[Hepatitis B]] | | * [[Hepatitis B]] |
| * [[Hepatitis B in China]]
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| * [[Hepatitis C]] | | * [[Hepatitis C]] |
| * [[Hepatitis E]] | | * [[Hepatitis E]] |
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| <br> | | <br> |
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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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