From Wikipedia, the free encyclopedia
Jump to: navigation, search
Virus classification
Group: Group IV ((+)ssRNA)
Order: Picornavirales
Family: Picornaviridae
Genus: Parechovirus
Type species
Parechovirus A

Parechovirus is a genus of viruses in the order Picornavirales, in the family Picornaviridae. Bank voles and humans serve as natural hosts. There are currently only two species in this genus including the type species Parechovirus A, also called human parechoviruses and Parechovirus B, more commonly known as the Ljungan virus.[1] Diseases associated with this genus include: human parechoviruses: mild, gastrointestinal or respiratory illness, have been implicated in cases of myocarditis and encephalitis; Ljungan virus: may be a zoonotic virus associated with diabetes and intrauterine fetal death in human.[2][3][4]


Group: ssRNA(+)


Six types of human parechovirus have been identified: human parechovirus 1 (HPeV1, formerly echovirus 22), human parechovirus 2 (formerly echovirus 23), and human parechoviruses 3, 4, 5 and 6.[5][6][7]

A total of 15 genotypes are currently recognised.[8]


Viruses in Parechovirus are non-enveloped, with icosahedral, spherical, and round geometries, and T=pseudo3 symmetry. The diameter is around 30 nm. Genomes are linear and non-segmented, around 7.3kb in length.[4]

Genus Structure Symmetry Capsid Genomic arrangement Genomic segmentation
Parechovirus Icosahedral[4] Pseudo T=3 Non-enveloped Linear Monopartite

Life cycle[edit]

Viral replication is cytoplasmic. Entry into the host cell is achieved by attachment of the virus to host receptors, which mediates endocytosis. Replication follows the positive stranded RNA virus replication model. Positive stranded RNA virus transcription is the method of transcription. The virus exits the host cell by lysis, and viroporins. Bank voles and human serve as the natural host.[2]

Genus Host details Tissue tropism Entry details Release details Replication site Assembly site Transmission
Parechovirus Humans Respiratory tract; gastrointestinal tract Cell receptor endocytosis Lysis Cytoplasm Cytoplasm Unknown


Infant with Parechovirus

Human parechoviruses cause mild, gastrointestinal or respiratory illness, but have been implicated in cases of myocarditis and encephalitis. Human parechoviruses are commonly spread and more than 95% of human cases are infected early in life, within two to five years of age.[9][10]

Parechovirus B has been proposed as a zoonotic virus, associated with diabetes and intrauterine fetal death in humans.[11][12] However, the data regarding these features are currently limited and need to be confirmed.

Parechovirus is a Biosafety Level 2 organism.


The first parechoviruses (E22 and E23) were isolated in 1956, and recognized as a new genus in 1996.[13][14] Parechovirus B was first isolated from bank voles (Myodes glareolus, formerly Clethrionomys glareolus) in the mid-1990s.[15]

Human parechovirus type 3 (HPeV3) was found in at least 20 U.S. young infants in 2014. Those numbers include a set of identical triplets from central Wisconsin, who contracted the virus and were diagnosed nearly two months later after a flurry of tests, as this was the first known case in those health systems.[16] The 2014 outbreak is a higher number than expected, and is thought to be linked to maternal-fetal transmission.[17]


  1. ^ "Parechovirus". Retrieved 2007-09-03. 
  2. ^ a b "Viral Zone". ExPASy. Retrieved 15 June 2015. 
  3. ^ a b ICTV. "Virus Taxonomy: 2014 Release". Retrieved 15 June 2015. 
  4. ^ a b c Shakeel, Shabih; Westerhuis, Brenda M.; Ora, Ari; Koen, Gerrit; Bakker, Arjen Q.; Claassen, Yvonne; Wagner, Koen; Beaumont, Tim; Wolthers, Katja C.; Butcher, Sarah J. (2015). "Structural Basis of Human Parechovirus Neutralization by Human Monoclonal Antibodies". Journal of Virology. 89 (18): 9571–9580. PMC 4542383Freely accessible. PMID 26157123. doi:10.1128/JVI.01429-15. 
  5. ^ Ito M, Yamashita T, Tsuzuki H, Takeda N, Sakae K (2004). "Isolation and identification of a novel human parechovirus". J. Gen. Virol. 85 (2): 391–398. PMID 14769896. doi:10.1099/vir.0.19456-0. 
  6. ^ Al-Sunaidi M, Williams CH, Hughes PJ, Schnurr DP, Stanway G (2007). "Analysis of a new human parechovirus allows the definition of parechovirus types and the identification of RNA structural domains". J. Virol. 81 (2): 1013–21. PMC 1797470Freely accessible. PMID 17005640. doi:10.1128/JVI.00584-06. 
  7. ^ Watanabe K, Oie M, Higuchi M, Nishikawa M, Fujii M (June 2007). "Isolation and characterization of novel human parechovirus from clinical samples". Emerg Infect Dis. 13 (6): 889–95. doi:10.3201/eid1306.060896. 
  8. ^ Chieochansin T, Vichiwattana P, Korkong S, Theamboonlers A, Poovorawan Y (2011) Molecular epidemiology, genome characterization, and recombination event of human parechovirus. Virology
  9. ^ Stanway G, Joki-Korpela P, Hyypiä T (2000). "Human parechoviruses--biology and clinical significance". Rev. Med. Virol. 10 (1): 57–69. PMID 10654005. doi:10.1002/(SICI)1099-1654(200001/02)10:1<57::AID-RMV266>3.0.CO;2-H. 
  10. ^ Joki-Korpela P, Hyypiä T (2001). "Parechoviruses, a novel group of human picornaviruses". Ann. Med. 33 (7): 466–71. PMID 11680794. doi:10.3109/07853890109002095. 
  11. ^ Niklasson B, Samsioe A, Papadogiannakis N, Kawecki A, Hörnfeldt B, Saade GR, Klitz W (2007). "Association of zoonotic Ljungan virus with intrauterine fetal deaths". Birth Defects Res. A Clin. Mol. Teratol. 79 (6): 488–93. PMID 17335057. doi:10.1002/bdra.20359. 
  12. ^ Niklasson B, Heller KE, Schonecker B, Bildsoe M, Daniels T, Hampe CS, Widlund P, Simonson WT, Schaefer JB, Rutledge E, Bekris L, Lindberg AM, Johansson S, Örtqvist E, Persson B, Lernmark Å (2003). "Development of type 1 diabetes in wild bank voles associated with islet autoantibodies and the novel ljungan virus". Int. J. Exp. Diabesity. Res. 4 (1): 35–44. PMC 2480497Freely accessible. PMID 12745669. doi:10.1080/15438600303733. 
  13. ^ Stanway, G., & Hyypiä, T. (1999). "Parechoviruses.". Journal of Virology. 73 (7): 5249–5254. 
  14. ^ Pringle, C.R. (1996). "Virus Taxonomy 1996". Archives of Virology. 141 (11): 2251–2256. doi:10.1007/BF01718231. 
  15. ^ Niklasson B, Kinnunen L, Hörnfeldt B, Hörling J, Benemar C, Hedlund KO, Matskova L, Hyypiä T, Winberg G (1999). "A new picornavirus isolated from bank voles (Clethrionomys glareolus)". Virology. 255 (1): 86–93. PMID 10049824. doi:10.1006/viro.1998.9557. 
  16. ^ "". Parechovirus Research. Retrieved 2016-01-15. 
  17. ^ "Viral meningitis in Kansas City-area babies probed". The Kansas City Star. The Associated Press. August 13, 2014. 

External links[edit]