Tilapia pond virus

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Tilapia pond virus
Systematics
Classification : Viruses
Area : Riboviria
Empire : Orthornavirae
Phylum : Negarnaviricota
Subphylum : Polyploviricotina
Class : Insthoviricetes
Order : Articulavirales
Family : Amnoonviridae
Genre : Tilapine virus
Type : Tilapia pond virus
Taxonomic characteristics
Genome : (-) ssRNA segmented
Baltimore : Group 5
Scientific name
Tilapia tilapinevirus
Short name
TiLV
Left
NCBI  Taxonomy: 2034996
ICTV Taxon History: 201855391

The tilapia pond virus ( Engl. Tilapia lake virus , officially tilapia tilapinevirus , TiLV) is as yet only genus Tilapinevirus the family of Amnoonviridae and is regarded as the cause of the tilapia pond virus disease (Tilapia lake virus disease), a disease of cichlids especially of the genera Sarotherodon and Oreochromis from the tilapia group . The virus was scientifically described for the first time in 2014 and characterized more precisely - but not yet conclusively - in 2016. The International Committee on Taxonomy of Viruses (ICTV) has set up a separate family Amnoonviridae for the genus (as of November 2018), which is closely related to the much more prominent family Orthomyxoviridae , for which the TiLV was proposed beforehand; both families belong to the class Articulavirales .

features

The genome of the virus consists of ten RNA -Abschnitten (segments) of negative polarity , whose largest segment indications of homology with the segment of the PB1 influenza virus C has. The remaining nine segments show no homologies with other scientifically described viruses, but their 5 'and 3' ends show characteristics of other orthomyxoviruses.

The virus only affects brackish and freshwater fish and is mainly transmitted from fish to fish, with young fish appearing to be the most susceptible; the incubation period is five to ten days, after which fish that survive the infection are immune . Virus detection comes in particular from the eyes, brain and liver of infected fish; the damage to the eyes can lead to clouding and, in severe cases, to the lens bursting . Other symptoms can include bleeding in the area of ​​the meninges and changes in the texture of the skin and spleen . In the laboratory, virus cultures succeed preferably in brain cells of the affected species.

The syncytial hepatitis of tilapia (SHT) pathogen, which was first described from Ecuador in 2014 , also has characteristics of the Orthomyxoviridae family and is partially genetically homologous with the tilapia pond virus; The visible symptom of this disease is ascites in particular , the histological findings are mainly the accumulation of lipoproteins in the liver cells and necrosis of the intestinal mucosa .

Economical meaning

Moving fish from pond to pond can spread the virus and cause great damage in aquaculture ; According to the World Organization for Animal Health (OIE), an epidemic spread of the virus led to the death of 100,000 individuals of the species Oreochromis niloticus in the Philippines in the summer of 2017 . Reports of fatal infections have also been received from Israel (where the first detected diseases occurred), Peru , Ecuador , Colombia , Egypt , Thailand , India , Malaysia and the Republic of China (Taiwan) . (As of February 2018).

The tilapine cichlids, which are usually sold as tilapia , comprise more than 100 species and, according to the Food and Agriculture Organization of the United Nations (FAO), form the world's largest group of farmed fish after carp with an annual production (2014) of 4.5 million tons . In Egypt alone, the economic damage caused by widespread infections amounted to around 100 million US dollars in the summer of 2015. Despite its economic importance, the viral disease has not yet been included in the OIE's Aquatic Animal Health Code .

See also

literature

  • Win Surachetpong et al .: Outbreaks of Tilapia Lake Virus Infection, Thailand, 2015-2016. In: Emerging Infectious Diseases. Volume 23, No. 6, 2017, pp. 1031-1033, doi: 10.3201 / eid2306.161278 .
  • Agustin Barría et al .: Genetic parameters for resistance to Tilapia Lake Virus (TiLV) in Nile tilapia (Oreochromis niloticus). In: Aquaculture. Volume 522, 2020, 735126, doi: 10.1016 / j.aquaculture.2020.735126 .

Web links

Individual evidence

  1. ↑ ICTV Master Species List 2018b v1 MSL # 34, Feb. 2019
  2. ↑ a b ICTV: ICTV Taxonomy history: Akabane orthobunyavirus , EC 51, Berlin, Germany, July 2019; Email ratification March 2020 (MSL # 35)
  3. ↑ Marina Eyngora et al .: Identification of a Novel RNA Virus Lethal to Tilapia. In: Journal of Clinical Microbiology. Volume 52, No. 12, 2014, pp. 4137-4146, doi: 10.1128 / JCM.00827-14
  4. ↑ Eran Bacharach et al .: Characterization of a Novel Orthomyxo-like Virus Causing Mass Die-Offs of Tilapia. In: mBio. Volume 7, No. 2, e00431-16, 2016, doi: 10.1128 / mBio.00431-16
  5. ↑ ICTV : Master Species List 2018a v1 , MSL including all taxa updates since the 2017 release. Fall 2018 (MSL # 33)
  6. ↑ a b World Organization for Animal Health: Tilapia Lake Virus (TiLV) - A Novel Orthomyxo-Like Virus. (Status: February 2018) On: oie.int , accessed on March 1, 2018 (PDF)
  7. ↑ Jorge del-Pozo et al .: Syncytial Hepatitis of Tilapia (Oreochromis niloticus L.) is Associated With Orthomyxovirus-Like Virions in Hepatocytes. In: Veterinary Pathology. Volume 54, No. 1, 2017, pp. 164-170, doi: 10.1177 / 0300985816658100
  8. ↑ World Organization for Animal Health: Immediate notification report. REF OIE 25278. On: oie.int of November 23, 2017
  9. ↑ World Organization for Animal Health: Immediate notification report. REF OIE 26027 . On: oie.int of February 27, 2018
  10. ↑ Saengchan Senapin et al .: Inapparent infection cases of tilapia lake virus (TiLV) in farmed tilapia. In: Aquaculture. Volume 487, 2018, pp. 51-55, doi: 10.1016 / j.aquaculture.2018.01.007
  11. ↑ Mohamed Fathi et al .: Identification of Tilapia Lake Virus in Egypt in Nile tilapia affected by 'summer mortality' syndrome. In: Aquaculture. Volume 473, pp. 430-432, 2017, doi: 10.1016 / j.aquaculture.2017.03.014
  12. ^ Aquatic Animal Health Code (2017). On: oie.int , as of June 2017