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News Article

Ocular thelaziosis continues to spread in Europe

First case of Thelazia callipaeda infection in an Austrian cat with no history of traveling abroad

Over the last 30 years, Thelazia callipaeda has increasingly been reported as an agent of ocular infections in animals and humans throughout Europe. The nematode, transmitted in Europe by a fruit fly (Phortica variegate), infects the conjunctival sac and associated ocular tissue of domestic and wild carnivores, rabbits and hares, and humans. An ocular infection caused by T. callipaeda can exhibit a variety of clinical signs ranging from mild to severe.

Following the first cases of ocular thelaziosis in dogs recorded recently in Austria, an article in Parasitology Research describes T. callipaeda infection in an Austrian cat with no history of travelling abroad.

The cat, from Deutschlandsberg in the southern state of Styria, showed serous ocular discharge, conjunctival hyperaemia and mild conjunctival oedema in the right eye. Mechanical removal of the parasite from the cat’s eye, in combination with milbemycin oxime/praziquantel oral treatment and topical use of tobramycin/dexamethasone eye drops, led to a complete resolution of the symptoms within two weeks.

The authors say the study is important, as the zoonotic parasite responsible for the infection is largely unknown in Austria. Co-author Georg Duscher, Vice Director of the Institute of Parasitology at Vetmeduni Vienna, said: “In view of the present data, increased awareness of medical and veterinary communities is imperative for preventing further infections in both animals and humans. As recently demonstrated in a study conducted in Spain, it is reasonable to expect more cases of ocular thelaziosis in the following years and its further expansion to new areas in Austria.”

Because the nematode originally occurred in the Far East, it has often been referred to as “oriental eye worm”. The first European case of ocular thelaziosis was described in Italy in 1989. T. callipaeda has since been reported in animals across Europe, including France (2007), Switzerland (2008), Germany (2010), Spain (2011), Portugal (2012), Bosnia and Herzegovina (2014), Croatia (2014), Serbia (2014), Romania (2015), Bulgaria (2016), Hungary (2016), Slovakia (2017) and Greece (2015).

How the parasite was introduced to Austria remains unknown. T. callipaeda may have arrived via pet travel, the illegal pet trade or the import of stray dogs from Eastern Europe. Another explanation links the spread of the parasite to the migration of infected wild carnivores, in particular foxes or the golden jackal.

Adnan Hodži, from the Institute of Parasitology at Vetmeduni Vienna, said: “The transmission by wild animals is a plausible scenario which could explain the introduction of the eye worm to Austria. Future studies should therefore focus on wild animals in order to assess the role they play in the ecoepidemiology of this zoonotic parasite.”

Read article: The first autochthonous case of feline ocular thelaziosis in Austria by Adnan Hodžić, Albert Payer and Georg Gerhard Duscher, published in Parasitology Research (2019) vol. 118, no. 4, pp. 1321-1324

Article details

  • Date
  • 01 May 2019
  • Source
  • Vetmeduni Vienna
  • Subject(s)
  • Dogs, Cats, and other Companion Animals