Enterovirus

Enterovirus
Virus classification
Group: Group IV ((+)ssRNA)
Order: Picornavirales
Family: Picornaviridae
Genus: Enterovirus
Type species
Enterovirus C
Species

Enterovirus A
Enterovirus B
Enterovirus C
Enterovirus D
Enterovirus E
Enterovirus F
Enterovirus G
Enterovirus H
Enterovirus J
Rhinovirus A
Rhinovirus B
Rhinovirus C

Enteroviruses are a genus of positive-sense single-stranded RNA viruses associated with several human and mammalian diseases.

Enteroviruses are named by their transmission-route through the intestine (enteric meaning intestinal).

Serologic studies have distinguished 71 human enterovirus serotypes on the basis of antibody neutralization tests. Additional antigenic variants have been defined within several of the serotypes on the basis of reduced or nonreciprocal cross-neutralization between variant strains. On the basis of their pathogenesis in humans and animals, the enteroviruses were originally classified into four groups, polioviruses, Coxsackie A viruses (CA), Coxsackie B viruses (CB), and echoviruses, but it was quickly realized that there were significant overlaps in the biological properties of viruses in the different groups. Enteroviruses isolated more recently are named with a system of consecutive numbers: EV68, EV69, EV70, EV71, etc.[1]

Enteroviruses affect millions of people worldwide each year, and are often found in the respiratory secretions (e.g., saliva, sputum, or nasal mucus) and stool of an infected person. Historically, poliomyelitis was the most significant disease caused by an enterovirus, poliovirus. There are 64 non-polio enteroviruses that can cause disease in humans: 23 Coxsackie A viruses, 6 Coxsackie B viruses, 28 echoviruses, and 5 other enteroviruses.[2] Poliovirus, as well as coxsackie and echovirus are spread through the fecal-oral route. Infection can result in a wide variety of symptoms ranging from mild respiratory illness (common cold), hand, foot and mouth disease, acute hemorrhagic conjunctivitis, aseptic meningitis, myocarditis, severe neonatal sepsis-like disease, and acute flaccid paralysis.[2]

Species and genetics

Maximum likelihood phylogenetic trees of enterovirus species A, B, C, D and rhinovirus A, B, C isolates from Latin America. The 5'UTR region is much more affected by recombination events than the VP4/VP2 coding sequence.[3]

Enteroviruses are members of the picornavirus family, a large and diverse group of small RNA viruses characterized by a single positive-strand genomic RNA. All enteroviruses contain a genome of approximately 7,500 bases and are known to have a high mutation rate due to low-fidelity replication and frequent recombination.[4] After infection of the host cell, the genome is translated in a cap-independent manner into a single polyprotein, which is subsequently processed by virus-encoded proteases into the structural capsid proteins and the nonstructural proteins, which are mainly involved in the replication of the virus.[5]

The enterovirus genus includes the following twelve species:[6]

Within these twelve species are the serotypes:

Coxsackie and echovirus

Coxsackie viruses are a non-phylogenetic group.[8] Coxsackie A viruses are mainly associated with human hand, foot and mouth disease. Coxsackie B viruses can cause signs and symptoms, similar to a "cold," but these viruses also can lead to more serious diseases, including myocarditis (inflammation of the heart); pericarditis (inflammation of the sac lining the heart); meningitis (inflammation of the membranes that line the brain and spinal cord); and pancreatitis (inflammation of the pancreas).

Echoviruses are a cause of many of the nonspecific viral infections. It is mainly found in the intestine, and can cause nervous disorders. The usual symptoms of Coxsackie and echovirus are fever, mild rash, and mild upper respiratory tract (URT) illness.

Enterovirus 68

Main article: Enterovirus 68

EV-D68 first was identified in California in 1962. Compared with other enteroviruses, it has been rarely reported in the U.S. in the past 40 years. Most people who get infected are infants, children and teens. EV-D68 usually causes mild to severe respiratory illness; however, the full spectrum of EV-D68 illness is not well-defined. Most start with common cold symptoms of runny nose and cough. Some, but not all, may also have fever. For more severe cases, difficulty breathing, wheezing or problems catching your breath may occur. As of October 4, 2014, there has been one death in New Jersey directly linked to EV-D68,[9] as well as one death in Rhode Island[10] attributed to a combination of EV-D68 and sepsis caused by an infection of staphylococcus aureus.[11][12]

Enterovirus 71

Main article: Enterovirus 71

Enterovirus 71 (EV-71) is notable as one of the major causative agents for hand, foot and mouth disease (HFMD), and is sometimes associated with severe central nervous system diseases.[13] EV71 was first isolated and characterized from cases of neurological disease in California in 1969.[14][15] To date, little is known about the molecular mechanisms of host response to EV71 infection, but increases in the level of mRNAs encoding chemokines, proteins involved in protein degradation, complement proteins, and proapoptotis proteins have been implicated.[16]

Poliovirus

Main article: Poliovirus

There are three serotypes of poliovirus, PV1, PV2, and PV3; each with a slightly different capsid protein. Capsid proteins define cellular receptor specificity and virus antigenicity. PV1 is the most common form encountered in nature; however, all three forms are extremely infectious.[17] Poliovirus can affect the spinal cord and cause poliomyelitis.

Polioviruses were formerly classified as a species belonging to the genus Enterovirus in the family Picornaviridae. The Poliovirus species has been eliminated from the genus Enterovirus. The following serotypes, Human poliovirus 1, Human poliovirus 2, and Human poliovirus 3, were assigned to the species Human enterovirus C, in the genus Enterovirus in the family Picornaviridae. The type species of the genus Enterovirus was changed from Poliovirus to Human enterovirus C. This has been ratified in April 2008.[18] The 39th Executive Committee (EC39) of the International Committee on Taxonomy of Viruses (ICTV) met in Canada during June 2007 with new taxonomic proposals.[19]
Two of the proposals with three changes were:

Proposals approved at the (EC39) meeting of 2007, were sent to members of ICTV via email for ratification and have become official taxonomy. There have been a total of 215 taxonomic proposals, which have been approved and ratified since the 8th ICTV Report of 2005.[22]
The ratification process was performed by email. The proposals were sent electronically via email on March 18, 2008 to ICTV members with a request to vote on whether to ratify the taxonomic proposals, with a 1-month deadline. The following are two of the taxonomic proposals with three changes that were ratified by ICTV members in April 2008:
Picornaviruses

The ICTVdb, International Committee on Taxonomy of Viruses data base, based on the ICTV Master Species List, 8th Report, June 2005 is obsolete.[6]

Diseases caused by enterovirus infection

Treatment

Treatment for enteroviral infection is mainly supportive. In cases of pleurodynia, treatment consists of analgesics to relieve the severe pain that occurs in patients with the disease; in some severe cases, opiates may be needed. Treatment for aseptic meningitis caused by enteroviruses is also mainly symptomatic. In patients with enteroviral carditis, treatment consists of the prevention and treatment of complications, such as arrhythmias, pericardial effusion, and cardiac failure. Other treatments that have been investigated for enteroviral carditis include intravenous immunoglobulin.[29]

References

  1. ↑ Oberste MS, Maher K, Kilpatrick DR, Pallansch MA (1999). "Molecular Evolution of the Human Enteroviruses: Correlation of Serotype with VP1 Sequence and Application to Picornavirus Classification". J. Virol. 73 (3): 1941–8. PMC 104435Freely accessible. PMID 9971773.
  2. 1 2 3 "Non-Polio Enterovirus Infections". CDC. 8 September 2014. Retrieved 9 September 2014.
  3. ↑ Josefina Garcia; et al. (2013). "Human rhinoviruses and enteroviruses in influenza-like illness in Latin America". Virol J. 10: 305. doi:10.1186/1743-422x-10-305. PMC 3854537Freely accessible. PMID 24119298.
  4. ↑ Li L, He Y, Yang H, et al. (2005). "Genetic Characteristics of Human Enterovirus 71 and Coxsackievirus A16 Circulating from 1999 to 2004 in Shenzhen, People's Republic of China". J. Clin. Microbiol. 43 (8): 3835–9. doi:10.1128/JCM.43.8.3835-3839.2005. PMC 1233905Freely accessible. PMID 16081920.
  5. ↑ Merkle I, van Ooij MJ, van Kuppeveld FJ, et al. (2002). "Biological Significance of a Human Enterovirus B-Specific RNA Element in the 3′ Nontranslated Region". J. Virol. 76 (19): 9900–9. doi:10.1128/JVI.76.19.9900-9909.2002. PMC 136489Freely accessible. PMID 12208967.
  6. 1 2
  7. ↑ "ICTV Master Species List 2009 - v10 (9th Report) - Master Species Lists - Master Species Lists - ICTV Collaboration". Talk.ictvonline.org. 2009-10-21. Retrieved 2016-04-14.
  8. ↑ Santti, Juhana; Heli Harvala; Leena Kinnunen; Timo Hyypia (2000). "Molecular epidemiology and evolution of coxsackievirus A9" (PDF). Journal of General Virology. 81 (Pt 5): 1361–1372. PMID 10769080. Retrieved 2009-08-09.
  9. ↑ Mohney, Gillian (4 October 2014). "Medical Examiner Finds NJ Preschooler Died Due to Enterovirus 68". ABCNews. Retrieved 6 October 2014.
  10. ↑ WDRI.com
  11. ↑ "The facts about enterovirus D68". Childrensmn.org. Children's Hospitals and Clinics of Minnesota.
  12. ↑ Malone, Scott (1 October 2014). "Rhode Island child with Enterovirus dies after infection: officials". Reuters. Retrieved 6 October 2014.
  13. ↑ Lin TY, Chu C, Chiu CH (2002). "Lactoferrin inhibits enterovirus 71 infection of human embryonal rhabdomyosarcoma cells in vitro". J. Infect. Dis. 186 (8): 1161–4. doi:10.1086/343809. PMID 12355368.
  14. ↑ Wang JR, Tuan YC, Tsai HP, Yan JJ, Liu CC, Su IJ (2002). "Change of Major Genotype of Enterovirus 71 in Outbreaks of Hand-Foot-and-Mouth Disease in Taiwan between 1998 and 2000". J. Clin. Microbiol. 40 (1): 10–5. doi:10.1128/JCM.40.1.10-15.2002. PMC 120096Freely accessible. PMID 11773085.
  15. ↑ Laboratory Investigation of a Suspected Enterovirus 71 Outbreak
  16. ↑ Shih SR, Stollar V, Lin JY, Chang SC, Chen GW, Li ML (2004). "Identification of genes involved in the host response to enterovirus 71 infection". J. Neurovirol. 10 (5): 293–304. doi:10.1080/13550280490499551. PMID 15385252.
  17. ↑ Paul JR (1971). A History of Poliomyelitis. (Yale studies in the history of science and medicine). New Haven, Conn: Yale University Press. ISBN 0-300-01324-8.
  18. ↑ "ICTV Newsletter #6 2008" (PDF). ICTV. February 2008. p. 1.
  19. ↑ "2005.261-262V.04.Polio.pdf - Vertebrate (through 2014) - Approved Proposals since the 8th Report - ICTV Collaboration". Talk.ictvonline.org. 2008-03-05. Retrieved 2016-04-14.
  20. ↑ "2005.263V.04.TypeSpEntero.pdf - Vertebrate (through 2014) - Approved Proposals since the 8th Report - ICTV Collaboration". Talk.ictvonline.org. 2008-03-05. Retrieved 2016-04-14.
  21. ↑ "ICTV Newsletter #7 2009" (PDF). ICTV. October 2009. p. 1.
  22. ↑ Seroka, Rachel (23 February 2014). "Mysterious polio-like illness found in 5 California children". American Academy of Neurology. Retrieved 24 February 2014.
  23. ↑ "Mysterious Polio-Like Illness Found in California Children". Voice of America. February 24, 2014. Retrieved 24 February 2014.
  24. ↑ Chia, JKS; et al. (2007). "Chronic fatigue syndrome is associated with chronic enterovirus infection of the stomach". J Clin Pathol. 61: 43–48. doi:10.1136/jcp.2007.050054.
  25. ↑ Fairweather, D; Rose, NR (2002). "Type 1 diabetes: virus infection or autoimmune disease?". Nat. Immunol. 3: 338–340. doi:10.1038/ni0402-338. PMID 11919574.
  26. ↑ "Finnish team makes diabetes vaccine breakthrough | Yle Uutiset". Yle.fi. Retrieved 2016-04-14.
  27. ↑ Laitinen, OH; et al. (2014). "Coxsackievirus B1 is associated with induction of β-cell autoimmunity that portends type 1 diabetes". Diabetes. 63: 446–455. doi:10.2337/db13-0619. PMID 23974921.
  28. ↑ Schwartz, R.A. "Enteroviruses Treatment & Management". Medscape.
This article is issued from Wikipedia - version of the 10/15/2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.