View source for B virus

{{Short description|Species of virus}}
{{Virusbox
| image = 5248420.fig.004-crop2.png
| image_alt = 
| image_caption = B virus spread in murine cells with time at 24 and 48-hours post infection (PI)
| parent = Simplexvirus
| species = Macacine alphaherpesvirus 1
| synonyms = 
*''Cercopithecine herpesvirus 1''<ref name=HerProp>{{cite web |last1=Davison |first1=Andrew |title=TAXONOMIC PROPOSALS FROM THE ''HERPESVIRIDAE'' STUDY GROUP |url=https://ictv.global/ictv/proposals/2005.020-72.04.Herpes.pdf |website=International Committee on Taxonomy of Viruses (ICTV) |access-date=13 March 2019 |page=3 |language=en |quote=2005.061V.04 To rename ''Cercopithecine herpesvirus 1'' in the genus ''Simplexvirus'' of the family ''Herpesviridae'' as ''Macacine herpesvirus 1''}}</ref>
*''Herpes virus B''<ref name=ICTV7>ICTV 7th Report van Regenmortel, M.H.V., Fauquet, C.M., Bishop, D.H.L., Carstens, E.B., Estes, M.K., Lemon, S.M., Maniloff, J., Mayo, M.A., McGeoch, D.J., Pringle, C.R. and Wickner, R.B. (2000). Virus taxonomy. Seventh report of the International Committee on Taxonomy of Viruses. Academic Press, San Diego. p210 https://ictv.global/ictv/proposals/ICTV%207th%20Report.pdf</ref>
*''Macacine 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=13 March 2019 |language=en |date=27 January 2016}}</ref>
| synonyms_ref = 
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'''B-virus''' (''Macacine alphaherpesvirus 1''; McHV-1; formerly ''Macacine herpesvirus 1'',<ref name="2015.010aD"/> ''Cercopithecine herpesvirus 1'',<ref name=HerProp/> CHV-1<ref>{{Cite web | url=http://cdc.gov/herpesbvirus | title=B Virus &#124; Home &#124; Herpes B &#124; CDC| date=2019-02-04}}</ref>), ''Herpesvirus simiae'', or ''Herpes virus B''<ref name=ICTV7/> is the ''[[Simplexvirus]]'' infecting [[macaque]] monkeys. B virus is very similar to HSV-1, and as such, this [[neurotropic virus]] is not found in the blood.

In the natural host, the [[virus]] exhibits [[pathogenesis]] similar to that of [[Herpes labialis|cold sores]] in humans. There have been a number of accidental infections and fatalities of researchers working with rhesus monkeys (''[[Rhesus macaque]]''). When humans are [[zoonotic]]ally infected with B virus, they can present with a severe [[encephalitis]], resulting in permanent neurological dysfunction or death. Severity of the disease increases for untreated patients, with a [[case fatality rate]] of approximately 80%. Early diagnosis and subsequent treatment are crucial to human survival of the infection.

[[Personal protective equipment]] is necessary when working with macaques, especially with animals that have tested positive for the virus. Bites, scratches, and exposures to [[mucous membrane]]s, including the eye, have led to infection when not cleaned immediately.

==History==
[[File:2014_Suchum,_Małpiarnia,_Makak_rezus_(12).jpg|thumb|[[Rhesus macaque|Rhesus monkeys]] are a [[natural reservoir|natural host]] of B virus and have on occasion caused fatal [[List of laboratory biosecurity incidents|infections in researchers]]]]
''Macacine alphaherpesvirus 1'' was first identified in 1932 following the death of William Brebner, a young physician who was bitten by a [[Rhesus macaque|rhesus monkey]] while doing research on [[polio]].<ref name=Pimentel08>{{Cite journal|last=Pimentel|first=Jason D.|date=2008-03-11|title=Herpes B virus — "B" is for Brebner: Dr. William Bartlet Brebner (1903–1932)|pmc=2263097 |journal=CMAJ: Canadian Medical Association Journal|volume=178|issue=6|pages=734|doi=10.1503/cmaj.071098}}</ref> He had healed from the bite but later developed a [[Fever|febrile]] illness,<ref>{{cite book |last=Hilliard|first=Julia|title=Monkey B virus|date=2007 |id=NBK47426 |url=http://www.ncbi.nlm.nih.gov/books/NBK47426/|work=Human Herpesviruses: Biology, Therapy, and Immunoprophylaxis|editor-last=Arvin|editor-first=Ann |publisher=Cambridge University Press|isbn=978-0-521-82714-0|pmid=21348110|access-date=2021-02-05|editor2-last=Campadelli-Fiume|editor2-first=Gabriella|editor3-last=Mocarski|editor3-first=Edward|editor4-last=Moore|editor4-first=Patrick S.}}</ref> resulting in localized [[erythema]], [[lymphangitis]], [[lymphadenitis]] and, ultimately, [[transverse myelitis]]. Neurologic tissues obtained during autopsy revealed the presence of an [[Virus|ultrafilterable agent]] that appeared similar to [[Herpes simplex virus 1|HSV-1]].<ref>{{cite journal|vauthors=Gay PP, Holden M|year=1933|title=Isolation of herpesvirus from several cases of epidemic encephalitis|journal=Proc Soc Exp Biol Med|volume=30|issue=8|pages=1051–3|doi=10.3181/00379727-30-6788|s2cid=88005854}}</ref> This isolate was originally termed "W virus."<ref name=Pimentel08 />

Within a year of Brebner's death, [[Albert Sabin]] identified a novel virus from the same samples,<ref name="Sabin1934">{{cite journal |vauthors=Sabin AB, Wright WM |title=Acute ascending myelitis following a monkey bite, with the isolation of a virus capable of reproducing the disease |journal=J Exp Med |issue=2 |pages=115–36 |year=1934 |pmid=19870235 |volume=59 |pmc=2132353| doi=10.1084/jem.59.2.115 }}</ref> which he later named B virus.<ref>{{Cite web|last=Norris|first=Melissa Cox|date=2012-09-07|title=The Albert B. Sabin Digitization Project: The Case of William Brebner {{!}} LiBlog|url=https://libapps.libraries.uc.edu/liblog/2012/09/the-albert-b-sabin-digitization-project-the-case-of-william-brebner/|access-date=2021-08-01|language=en-US}}</ref> Sabin further described the lethality of ''Macacine alphaherpesvirus 1'' by showing that infectivity was independent of the route of inoculation.<ref name="Sabin1934"/> Additionally, it was observed that ''Macacine alphaherpesvirus 1'' induced immunologic responses similar to HSV-1<ref name="Sabin1934a">{{cite journal |author=Sabin AB |title=Studies on the B virus I: The immunological identity of a virus isolated from a human case of ascending myelitis associated with visceral necrosis |journal=Br J Exp Pathol |issue=15 |pages=248–68 |year=1934 |volume=15 |pmc=2065030}}</ref> and shared similarities to [[Herpesvirus papio|HVP]]-2 and Langur herpesvirus, two other nonhuman primate alphaherpesviruses.<ref name="Sabin1934a"/><ref name="PMID7613729">{{cite journal |vauthors=Eberle R, Hilliard J |title=The simian herpesviruses |journal=Infectious Agents and Disease |volume=4 |issue=2 |pages=55–70 |year=1995 |pmid=7613729}}</ref><ref name="Sabin1934b">{{cite journal |author=Sabin AB |title=Studies on the B virus II: Properties of the virus and pathogenesis of the experimental disease in rabbits |journal=Br J Exp Pathol |issue=15 |pages=269–79 |year=1934 |volume=15 |pmc=2065027}}</ref><ref name="Sabin1934c">{{cite journal |author=Sabin AB |title=Studies on the B virus III: The experimental disease in macacus rhesus monkeys |journal=Br J Exp Pathol |issue=15 |pages=321–34 |year=1934 |volume=15 |pmc=2065017}}</ref><ref name="Burnet1939">{{cite journal |vauthors=Burnet FM, Lush D, Jackson AV |title=The properties of herps B and pseudorabies viruses on the choriollantois |journal=Aust J Exp Biol Med Sci |volume=17 |issue=17 |pages=35–52 |year=1939|doi=10.1038/icb.1939.4 }}</ref><ref name="Burnet1939a">{{cite journal |vauthors=Burnet FM, Lush D, Jackson AV |title=The relationship of herpse and B viruses: immunological and epidemiological considerations |journal=Aust J Exp Biol Med Sci |volume=17 |issue=17 |pages=41–51 |year=1939|doi=10.1038/icb.1939.5 }}</ref>

By 1959, ''Macacine alphaherpesvirus 1'' was identified as the causative agent in 17 human cases, 12 of which resulted in death.<ref name="Breen1958">{{cite journal |vauthors=Breen GE, Lamb SG, Otaki AT |title=Monkey bite encephalomyelitis: report of a case with recovery |journal=Br Med J |issue=5087 |pages=22–3 |year=1958 |pmid=13546633 |volume=2 |pmc=2025841 |doi=10.1136/bmj.2.5087.22}}</ref><ref name="Hummeler1959">{{cite journal  |vauthors=Hummeler K, Davidson WL, Henle W, etal |title=Encephalomyelitis due to infection with herpesvirus simiae (herpes B virus): a report of two fatal, laboratory acquired cases |journal=New England Journal of Medicine |issue=2 |pages=64–8 |year=1959 |doi=10.1056/NEJM195907092610203 |volume=261 |pmid=13666979}}</ref><ref name="Pierce1958">{{cite journal |vauthors=Pierce EC, Pierce JD, Hull RN |title=B virus: its current significance, description and diagnosis of a fatal human infection |journal=Am J Hyg |issue=68 |pages=242–50 |year=1958 |volume=68 |pmid=13594926}}</ref> Approximately 50 cases had been identified by 2002, although only 26 were well documented. Improvements in handling human cases have been made in the past several decades. Between 1987 and 2004, the mortality rate decreased, largely due to the addition of new forms of treatment and improved diagnosis. There have been a total of five fatalities related to ''Macacine alphaherpesvirus 1'' in this period.<ref name="wwwnc">{{Cite web | url=http://wwwnc.cdc.gov/travel/page/yellowbook-2012-home.htm | title=2018 Yellow Book Home &#124; Travelers' Health &#124; CDC}}</ref>

In 1997 researcher Elizabeth Griffin was splashed in the eye by an infected rhesus monkey while working at the [[Yerkes National Primate Research Center]] and she subsequently died.<ref>{{cite web|title=Welcome ergriffinresearch.org - BlueHost.com|url=http://www.ergriffinresearch.org/about-elizabeth/|url-status=dead|archive-url=https://web.archive.org/web/20121101233505/http://www.ergriffinresearch.org/about-elizabeth/|archive-date=1 November 2012|access-date=13 March 2019|website=www.ergriffinresearch.org}}</ref><ref name=":2" />
In 2019, a researcher working with monkeys at a Japanese pharmaceutical company became infected and critically ill.<ref name=":1" /> In 2021, a veterinarian in China became infected while performing two [[dissection]]s on rhesus monkeys and subsequently died.<ref name=":0" /> 

==Virology==
===Structure===
''Macacine alphaherpesvirus 1'' is approximately 200&nbsp;nm in diameter and has a structure almost identical to that of [[HSV1]] and [[Herpes simplex virus 2|HSV2]]. It has an [[icosahedron|icosahedral]] capsid (T=16) consisting of 150 [[Hexon protein|hexon]]s and 12 pentons formed from 6 proteins. The envelope is loose around the viral capsid and contains at least 10 glycoproteins critical for [[virus life cycle#Adsorption|adsorption]] and [[virus life cycle#Penetration|penetration]] into host cells. The [[Viral tegument|tegument]], containing at least 14 proteins, lies between the capsid and the envelope. The tegument proteins are involved in [[nucleic acid metabolism]], [[DNA synthesis]], and [[post-translational processing|protein processing]]. The proteins in the tegument are [[thymidine kinase]], [[thymidylate synthetase]], [[dUTPase]], [[ribonucleotide reductase]], [[DNA polymerase]], [[DNA helicase]], [[DNA primase]], and [[protein kinase]]s.<ref>{{cite book |last1=Knipe |first1=D.M. |author-link=David M. Knipe |last2=Howley |first2=P.M. |author2-link=Peter Howley |title=Fields virology |publisher=Wolters Kluwer Health |edition=6th |date=2013 |isbn=9781469830667 }}</ref><ref>{{cite book |first=N.H. |last=Acheson |title=Fundamentals of molecular virology |publisher=Wiley |edition=2nd |date=2011 |isbn=9780470900598 }}</ref>

===Genome===
The B virus [[genome]] was fully sequenced in 2003 from an isolate found in a [[rhesus macaque]].<ref name="Perelygina2003">{{cite journal  |vauthors=Perelygina L, Zhu L, Zurkuhlen H, etal |title=Complete sequence and comparative analysis of the genome of herpes b virus (Cercopithecine herpesvirus 1) from a rhesus monkey |journal=Journal of Virology |volume=77 |issue=11 |pages=6167–77 |year=2003 |pmid=12743273 |pmc=155011 |doi=10.1128/JVI.77.11.6167-6177.2003}}</ref> Like all herpes viruses, the B virus genome contains double-stranded [[DNA]] and is approximately 157 [[Base pair#Length measurements|kbp]] in length. Two unique regions (UL and US) are flanked by a pair of inverted repeats, two of which are found at the termini, with the other two internally located. This arrangement, which is identical in nature to HSV, results in four sequence-oriented isomers. [[Cytosine]] and [[guanine]] nucleotides represent 75% of the sequence.

Sequence analyses suggest that B virus and HSV types 1 and 2 most likely diverged from a common ancestor during the evolution of these pathogens. Each gene-encoded [[glycoprotein]], including gB, gC, gD, gE and gG, has approximately 50% homology with HSV, with a slightly higher predilection towards HSV-2 over HSV-1.<ref name="Perelygina2003"/> Additionally, glycoprotein sequences have demonstrated that all cysteine residues are conserved, as are most [[glycosylation]] sites.  One key difference between the B virus and the HSVs is that B virus does not have a homolog of the HSV γ<sub>1</sub>34.5 gene, which codes for a neurovirulence factor.<ref name="Perelygina2003"/>  This indicates that B virus has different mechanisms from HSV for replicating inside [[nerve cell]]s, which could explain the drastically different effects of these viruses on humans.

==Infection==
In the natural host, the [[virus]] exhibits [[pathogenesis]] similar to that of [[Herpes labialis|cold sores]] in humans.<ref name=Liu>{{cite book |first=D. |last=Liu |chapter=4. Cercopithecine herpesvirus1 (B Virus) |chapter-url=https://books.google.com/books?id=liUyAwAAQBAJ&pg=PA36 |title=Manual of Security Sensitive Microbes and Toxins |publisher=Taylor & Francis |date=2014 |isbn=9781466553965 |pages=31–36 |url=}}</ref>  
===Humans===

B virus infection of humans is extremely rare. People typically get infected with B virus if they are bitten or scratched by an infected macaque monkey, or have contact with the monkey's eyes, nose, or mouth. Only one case has been documented of an infected person spreading B virus to another person.<ref name=CDC>{{Cite web|date=2021-03-18|title=Herpes B Virus|url=https://www.cdc.gov/herpesbvirus/index.html|access-date=2021-07-19|website=www.cdc.gov|language=en-us}}</ref>
Traveling to an area where macaques are known carriers of the virus and interacting in close contact in areas such as temples poses a risk of exposure. However, even in endemic areas, human cases are rare. There have been no known cases of ''Macacine alphaherpesvirus 1'' in travelers.<ref name="wwwnc" />

When humans are [[zoonotic]]ally infected with B virus, they can develop [[encephalitis]], resulting in permanent neurological dysfunction or death. The severity of the disease increases for untreated patients. As of 2014, there was a [[case fatality rate]] of approximately 80%.<ref name=Liu/>

As of 2020, there have been 50 documented cases of human B virus infection since the identification of the virus in 1932, 21 of which led to death.<ref>{{Cite web|url = https://www.cdc.gov/herpesbvirus/cause-incidence.html|title = <nowiki>B Virus | Cause and Incidence</nowiki>|date =  January 28, 2019|access-date = April 6, 2020|publisher = CDC}}</ref> At least 20 of the patients developed some degree of [[encephalitis]].<ref name="wustl_factsheet">{{Cite web|url=https://research.wustl.edu/offices/dcm/|archiveurl=https://web.archive.org/web/20080106224228/http://dcminfo.wustl.edu/occhealth/factsheet_herpesb.html |url-status=dead|title=Division of Comparative Medicine (DCM) &#124; Research &#124; Washington University in St. Louis|archivedate=January 6, 2008|website=Research}}</ref><ref name="PMID1313312">{{cite journal
|title=Biology of B virus in macaque and human hosts: a review
|journal=Clinical Infectious Diseases
|year=1992
|author=Weigler BJ
|volume=14
|issue=2
|pages=555–67
|pmid=1313312
|doi=10.1093/clinids/14.2.555}}</ref>

B virus is the only identified [[Old World monkey|old-world-monkey]] herpesvirus that displays severe pathogenicity in humans.{{cn|date=March 2024}}

==Prevention==
[[Personal protective equipment]] is necessary when working with macaques, especially with animals that have tested positive for the virus. Bites, scratches, and exposures to [[mucous membrane]]s, including the eye, have led to infection when not cleaned immediately.<ref>{{Cite journal|last1=Cohen|first1=Jeffrey&nbsp;I.|last2=Davenport|first2=David&nbsp;S.|last3=Stewart|first3=John&nbsp;A.|last4=Deitchman|first4=Scott|last5=Hilliard|first5=Julia&nbsp;K.|last6=Chapman|first6=Louisa&nbsp;E.|date=2002-11-15|title=Recommendations for Prevention of and Therapy for Exposure to B Virus (Cercopithecine Herpesvirus1)|journal=Clinical Infectious Diseases|volume=35|issue=10|pages=1191–1203|doi=10.1086/344754|pmid=12410479|issn=1058-4838|doi-access=free}}</ref><ref name=":0">{{Cite web|date=2021-07-18|title=China reports first human death from Monkey B Virus. All you need to know|url=https://www.hindustantimes.com/world-news/china-reports-first-human-death-from-monkey-b-virus-all-you-need-to-know-101626613612420.html|access-date=2021-07-20|website=Hindustan Times|language=en}}</ref><ref name=":1">{{Cite web|title=Japan's first human infection with B virus {{!}} NHK WORLD-JAPAN News|url=https://www3.nhk.or.jp/nhkworld/en/news/20191128_40/|url-status=dead|archive-url=https://web.archive.org/web/20191129123549/https://www3.nhk.or.jp/nhkworld/en/news/20191128_40/|archive-date=2019-11-29|access-date=2019-11-30|website=NHK WORLD|language=en}}</ref><ref name=":2">{{Cite news|last=Bragg|first=Rick|date=December 14, 1997|title=A Drop of Virus From a Monkey Kills a Researcher in 6 Weeks|work=[[The New York Times]]|url=https://www.nytimes.com/1997/12/14/us/a-drop-of-virus-from-a-monkey-kills-a-researcher-in-6-weeks.html}}</ref>

==Treatment==
Early diagnosis and subsequent treatment are crucial to human survival of the infection. Upon potential infection, samples from both the human and, when possible, the macaque should be sent for B virus diagnostic testing.<ref>{{Cite web|url = https://www.cdc.gov/herpesbvirus/specimen-collect.html|title = <nowiki>B Virus | Specimen Collection and B virus Detection</nowiki>|date = July 18, 2014|access-date = October 6, 2014|publisher = CDC}}</ref>

[[Acyclovir]] has prevented progression of the disease in some patients and may be lifesaving, though it is thought to be only one-tenth as effective against B virus as against HSV1.<ref>{{cite journal |vauthors=Elmore D, Eberle R |title=Monkey B virus (Cercopithecine herpesvirus 1) |journal=Comp Med |volume=58 |issue=1 |pages=11–21 |date=2008 |pmid=19793452 |pmc=2703160}}
</ref> Prompt treatment is essential to prevent permanent neurological impairment.<ref name="Ostrowski">{{cite journal
|title=B-virus from Pet Macaque Monkeys: An Emerging Threat in the United States?
|journal=Emerging Infectious Diseases
|date=January–March 1998
 |vauthors=Ostrowski Stephanie R, etal |volume=4
|issue=1
|pages=117–121
|doi=10.3201/eid0401.980117 
|pmid=9452406
 |pmc=2627675}}</ref>

==References==
{{Reflist|30em}}

==External links==
{{Wikispecies}}
* [https://www.cdc.gov/herpesbvirus/index.html CDC/NCID B Virus Page]
* [http://www.gsu.edu/bvirus B Virus Resource Laboratory]
* {{cite journal |vauthors=Pimentel JD |doi=10.1503/cmaj.071098 |journal=CMAJ |date=2008 |volume=178 |issue=6 |page=734 |title=Herpes B virus — "B" is for Brebner: Dr. William Bartlet Brebner (1903–1932)|pmc=2263097 }}

{{Herpesvirales}}
{{Viral cutaneous conditions}}
{{Zoonotic viral diseases}}
{{Taxonbar|from=Q24808672|from2=Q1330599|from3=Q30009625}}

{{DEFAULTSORT:Herpes B Virus}}
[[Category:Simplexviruses]]
[[Category:Viral encephalitis]]