Hyalomma

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Hyalomma
Hyalomma marginatum

Hyalomma marginatum

Systematics
Superordinate : Parasitiformes
Order : Ticks (ixodida)
Subordination : Ixodina
Family : Amblyommidae
Subfamily : Rhipicephalinae
Genre : Hyalomma
Scientific name
Hyalomma
CL Koch , 1844

Hyalomma (from ancient Greek ὕαλος hýalos "glass" and ὄμμα OMMA "eye") is a genus of ticks with about 27 species , many of them as carriers of disease - especially for the Crimean-Congo hemorrhagic fever and tick typhus be held responsible - .

Occurrence

The genus is widespread in the arid and semi- arid regions of Africa, Asia and Europe, it did not occur in Northern and Central Europe for a long time, in particular it was not able to survive cold winters there.

Ticks of this genus were observed in Switzerland in 1975. It was assumed that they were introduced by migratory birds, as the Hyalomma can cling to their host for up to four weeks. There is no systematic recording in Switzerland; According to the University of Zurich , a specific search would lead to specimens of this genus.

In 2015, a specimen of Hyalomma rufipes sucking on a horse was detected for the first time in Germany . After two individual finds in 2015 and 2017, seven specimens were found in Germany in 2018 that were presumably introduced by birds. Scientists attribute their occurrence to the hot, dry summer in Germany, as Hyalomma needs a low level of humidity. Rickettsia bacteria, which cause tick spotted fever , were found in one animal . It was detected in North Rhine-Westphalia in October 2018, and in December 2018 it was also found in Schleswig-Holstein . New tick finds in June 2019 - five animals were discovered on a horse farm in North Rhine-Westphalia, another in Lower Saxony - suggest that the tropical tick was able to overwinter in Germany for the first time. Researchers at the University of Hohenheim and the University of the Federal Armed Forces in Munich concluded this from the age of the animals. In August 2019, a Hyalomma tick was the first official carrier of typhus in Germany.

description

The genus Hyalomma includes at least 27 species that are difficult to differentiate morphologically. The representatives are two, some also three host. Eyes are present. Festons can be present or absent. The capitulum and palps are long. The back shield ( scutum ) is without ornaments. Male adults have protruding adanal shields on the underside and accessory shields adjoining them laterally. In comparison to the common wood tick , which is common in Central Europe , the Hyalomma is significantly larger. The Hyalomma tick actively hunts, has good eyesight, and runs fast so it can track its prey for several hundred meters.

Relevance as a disease vector

It is known that ticks of the genus Hyalomma can be the vector and reservoir of the Crimean-Congo virus . In addition, they are potentially also vectors for other viruses, some of which have not been well characterized in terms of their human pathogenicity ( Bhanja , Togoto , Dori or Batken virus ) and a number of bacteria. In a statement from February 2019, the Robert Koch Institute (RKI) rated the Crimean-Congo virus as the most relevant pathogen that can be transmitted by Hyalomma . The tick specimens found at the RKI, molecularly characterized in more detail, belonged to the species H. rufipes and H. marginatum , which are known to parasitize on birds, which speaks for an introduction by migratory birds. The example of Turkey shows that such introductions can develop very dynamically. From the first recorded cases in 2002 to 2019, more than 10,000 cases of Crimean-Congo fever have been recorded in Turkey with a mortality rate of almost 5 percent. Close contact with farm animals was the main risk factor.

Systematics

The genus is divided into at least three sub-genera:

  • Euhyalomma
  • Hyalomma Koch , 1844
  • Hyalommasta Schulze , 1930

The species:

Web links

Commons : Hyalomma  - collection of images, videos and audio files

Individual evidence

  1. ^ A b Peter Deplazes, Johannes Eckert , Georg von Samson-Himmelstjerna, Horst Zahner: Textbook of Parasitology for Veterinary Medicine . 3. Edition. Georg Thieme, Stuttgart 2012, ISBN 978-3-8304-1205-2 , p. 391 ( limited preview in Google Book search).
  2. ↑ Celine Müller: New type of tick: What pharmacists need to know about the Hyalomma tick. In: Deutsche Apothekerzeitung . August 15, 2018, accessed August 16, 2018 .
  3. ↑ Birds bring super ticks from Africa to Switzerland . In: 20 minutes . ( 20min.ch [accessed on August 15, 2018]).
  4. ↑ Heat and drought favor tropical tick species . In: Neue Zürcher Zeitung . August 15, 2018, ISSN  0376-6829 ( nzz.ch [accessed August 15, 2018]).
  5. ↑ G. Dobler, L. Zöller: Bundeswehr researchers discover tropical ticks in Germany. Institute for Microbiology of the Bundeswehr, March 28, 2017, accessed on June 11, 2019.
  6. ↑ Tropical ticks found in Germany. orf.at, August 14, 2018, accessed August 14, 2018.
  7. ↑ Experts alert: Tropical tick reaches Germany. tagesschau.de, August 14, 2018, accessed August 15, 2018.
  8. ↑ Tick ​​alert! Service time, WDR television, April 22nd. 2019.
  9. ↑ Dangerous tick first discovered in Schleswig-Holstein. In: welt.de . January 29, 2019, accessed June 11, 2019.
  10. ↑ Tropical ticks overwintered in Germany for the first time. In: Spiegel Online. June 11, 2019, accessed June 11, 2019.
  11. ↑ Introduced Hyalomma tick: Giant tick transmits typhus for the first time in Germany . In: Spiegel Online . August 14, 2019 ( spiegel.de [accessed August 14, 2019]).
  12. ^ A b Peter Hagedorn: Find of ticks of the genus Hyalomma in Germany . In: Robert Koch Institute (Ed.): Epidemiologisches Bulletin . No. 7 , February 14, 2019, doi : 10.25646 / 5893 .
  13. ↑ Johannes Kaufmann: Parasitic Infections of Domestic Animals: A Diagnostic Manual . ILRI, 1996, ISBN 978-3-7643-5115-1 , pp. 119 .
  14. ^ Daniel E. Sonenshine, R. Michael Roe: Biology of Ticks, Volume 1 . Oxford University Press, 2013, ISBN 978-0-19-974405-3 , pp. 38 .
  15. ^ Tropical tick species: Several finds in Germany worry experts. Press release from the University of Hohenheim with a comparison photo. August 14, 2018, accessed June 11, 2019.
  16. ↑ Tropical tick species overwinters for the first time in Germany. In: Zeit Online . June 11, 2019, accessed June 11, 2019 .
  17. ↑ Tropical tick: How dangerous is Hyalomma? In: Norddeutscher Rundfunk . August 20, 2018, accessed June 11, 2019 .
  18. ↑ genus Hyalomma . www.biolib.cz. Accessed January 30, 2019.
  19. ^ Hyalomma at Fauna Europaea. Accessed January 30, 2019
  20. ↑ M. Gharbi & MA Darghouth: A review of Hyalomma scupense (Acari, Ixodidae) in the Maghreb region: from biology to control . In: Parasite . tape 21 , 2014, doi : 10.1051 / parasite / 2014002 , PMC 3917376 (free full text).