Getah virus is a mosquito-borne arbovirus in the Alphavirus genus. The virus was first isolated in Malaysia in 1955 from the Culex gelidus mosquito. It has been known to infect pigs but more commonly affects horses.[2] The virus was isolated near rubber plantations; the word Getah means rubber in Malay. The first outbreak among racehorses occurred in Japan September–November 1978.[2] Getah virus is widely distributed in South-east Asian countries and while previous studies have indicated the presence of Getah virus in Northern Australia[3] these have recently been brought into question.[4]
| Getah virus | |
|---|---|
Virus classification 
| |
| (unranked): | Virus |
| Realm: | Riboviria |
| Kingdom: | Orthornavirae |
| Phylum: | Kitrinoviricota |
| Class: | Alsuviricetes |
| Order: | Martellivirales |
| Family: | Togaviridae |
| Genus: | Alphavirus |
| Species: | Getah virus
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| Synonyms[1] | |
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Genome
editGetah virus has a positive-sense single stranded RNA genome. According to Baltimore Classification System, this virus is in Group IV.
The virus appears to have evolved about 1872 (95% range: 1773 - 1942) and has diverged into four lineages.[5]
Transmission & infection
editThe virus is transmitted by mosquitoes, specifically those in the Aedes and Culex genera. It is also transmitted between horses through aerosols or direct nasal contact, though this seems unlikely since a large portion of virus particles are necessary for transmission and are found in lower numbers in nasal secretions.[6]
In horses, the virus causes fever, rash, edema of the hind legs, and swelling of the lymph nodes. In inoculated horses, the symptoms manifested themselves beginning 2–4 days post infection.[7] In pigs, the virus causes miscarriage; symptoms occurred 1–3 days after experimental infection.[6] Though the virus does not produce illness in humans, neutralizing antibodies have been identified within humans.[3]
Treatment
editThere is an inactivated-virus vaccine for horses. Once the horse is infected, supportive therapy is the only treatment available. Horses usually make a full recovery after 1 to 2 weeks. No Getah virus deaths have been reported in horses in clinical settings, and deaths only occur in pigs in the fetal stage.[6]
References
edit- ^ https://ictv.global/report/chapter/togaviridae/togaviridae/alphavirus November 2023
- ^ a b Nemoto M, Bannai H, Tsujimura K, Kobayashi M, Kikuchi T, Yamanaka T, Kondo T (2015). "Getah Virus Infection among Racehorses, Japan, 2014". Emerging Infectious Diseases. 21 (5): 883–5. doi:10.3201/eid2105.141975. PMC 4412242. PMID 25898181.
- ^ a b Zhai, You-gang (2008). "Complete sequence characterization of isolates of Getah virus (genus Alphavirus, family Togaviridae) from China". Journal of General Virology. 89 (Pt 6): 1446–1456. doi:10.1099/vir.0.83607-0. PMID 18474561.
- ^ Rawle DJ, Nguyen W, Dumenil T, Parry R, Warrilow D, Tang B; et al. (2020). "Sequencing of Historical Isolates, K-mer Mining and High Serological Cross-Reactivity with Ross River Virus Argue against the Presence of Getah Virus in Australia". Pathogens. 9 (10): 848. doi:10.3390/pathogens9100848. PMC 7650646. PMID 33081269.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ Li YY, Liu H, Fu SH, Li XL, Guo XF, Li MH, Feng Y, Chen WX3, Wang LH, Lei WW, Gao XY, Lv Z, He Y, Wang HY, Zhou HN, Wang GQ, Liang GD (2017) From discovery to spread: The evolution and phylogeny of Getah virus. Infect Genet Evol 55:48-55
- ^ a b c "The Center for Food Security & Public Health - Iowa State University" (PDF). March 2017.
- ^ Nemoto, Manabu (2016). "Genomic, pathogenic, and antigenic comparisons of Getah virus strains isolated in 1978 and 2014 in Japan". Archives of Virology. 161 (6): 1691–1695. doi:10.1007/s00705-016-2840-9. PMID 27016932. S2CID 254051389.