Suspected autochthonous Thelazia callipaeda infection in a dog in northern Germany
- PDF / 298,335 Bytes
- 4 Pages / 595.276 x 790.866 pts Page_size
- 72 Downloads / 156 Views
HELMINTHOLOGY - SHORT COMMUNICATION
Suspected autochthonous Thelazia callipaeda infection in a dog in northern Germany Sophia L. Lebedewa 1 & Kevin Tkocz 2 & Peter-Henning Clausen 1 & Ard M. Nijhof 1 Received: 22 January 2020 / Accepted: 5 October 2020 # The Author(s) 2020
Abstract A 12-year old Elo dog was presented with recurring symptoms of conjunctivitis in November 2019. A single whitish nematode was found upon inspection of the eye and identified as a Thelazia callipaeda male. The morphological identification of the eye worm was supported by analysis of a partial cytochrome c oxidase I (cox1) gene sequence. The dog lived in Lower Saxony, northwestern Germany, and had not visited regions known to be endemic for T. callipaeda. This suggests that a local transmission cycle of this zoonotic nematode may exist in Germany. Keywords Thelazia callipaeda . Germany . Cytochrome c oxidase I . Zoonosis
Introduction Thelazia callipaeda (Spirurida, Thelaziidae) are nematodes that occur in the eyes of carnivores, particularly dogs and foxes, as well as lagomorphs and sometimes humans (Gama et al. 2016; Otranto and Deplazes 2019). The parasite was first described from Asia in 1910 (Railliet and Henry 1910), where it is widespread. The first case of canine thelaziosis in Europe was described in Italy in the late 1980s (Rossi and Bertaglia 1989), and the distribution of this ’oriental eye worm’ has since extended to larger parts of Europe, with enzootic areas in southern Europe (do Vale et al. 2019). Adult T. callipaeda lives in the orbital cavity of the definitive host, where they reach sexually maturity after about 3– 4 weeks post-infection and can survive for more than 1 year (Faust 1928; Kozlov 1962; Anderson 2000; Otranto et al. 2004). First-stage larvae (L1) produced by the larviparous female eye worm are released in the lachrymal secretions. The non-biting fruit fly Phortica variegata that feed on these secretions can become infected with the L1 and act as intermediate hosts and vector for this nematode in Europe (Otranto
and Dantas-Torres 2015). Under natural conditions, male P. variegata flies appear to be the main vectors for T. callipaeda, as female P. variegata flies prefer fruit as their food source, whereas males show a more zoophilic behaviour (Otranto et al. 2006). In male P. variegata, the L1 migrates from the crop to the testes where it develops to the infective L3 stage. The L3 migrates back to the proboscis from where it is transmitted to the definitive host when the fly feeds on ocular secretions again (Otranto et al. 2005). Further development to the adult stage takes place on the surface of the eye. Infections with T. callipaeda may be subclinical but can also cause symptoms of conjunctivitis such as lacrimation and pruritus and, in severe cases, keratitis and ulceration (Marino et al. 2020). Canine thelaziosis caused by T. callipaeda has previously been reported from Germany and was associated with travel to an endemic region in Italy (Hermosilla et al. 2004) or originated from a region close to the
Data Loading...
