Spreading of Thelazia callipaeda in Greece

Abstract

Summary Thelazia callipaeda (Spirurida, Thelaziidae), the so‐called oriental eyeworm, has been increasingly reported as an agent of infection in animals and humans from many European countries. Clinical signs range from subclinical to moderate or severe ocular disorders (e.g., epiphora, photophobia, conjunctivitis, keratitis, ulcers). The disease has been also diagnosed in animals from countries of the Balkan area (e.g., Croatia, Bosnia and Herzegovina and Serbia), but only a single case of canine thelaziosis, presumably autochthonous, was reported in Northern Greece. In this study, we provide robust information of the occurrence of thelaziosis in Greece by reporting autochthonous cases of thelaziosis in dogs (n = 46), cats (n = 3) and in one rabbit (Oryctolagus cuniculus) living in Northern and Central regions of Greece. The occurrence of a single haplotype of the cytochrome oxidase subunit 1 gene confirms that the same zoonotic haplotype of the parasite circulating in Europe is also spreading in Greece. The increased awareness of this parasitosis is crucial to limit the risk of further infections in both humans and animals in European countries.

Population structure analysis of the neglected parasite Thelazia callipaeda revealed high genetic diversity in Eastern Asia isolates

“…callipaeda in Anhui of China was transmitted by P . okadai [ 9 , 12 ]. Although it is still unknown whether other vector species exist in Asian countries, considering the high genetic diversity of T .…”

“…The first human case was described in Beijing, China in 1917 [ 8 ]. Although sporadic human thelaziosis has been reported in several European countries, human infections are mainly documented in people living in China, Japan, Korea and India [ 9 ]. China is most likely to have the largest number of cases of thelaziasis in the world with more than 600 cases reported to date [ 10 ].…”

“…Consequently, T . callipaeda poses a serious threat to public health and thelaziosis has even been termed as an emerging enzootic disease [ 1 , 6 , 9 ]. Understanding the host specificity, transmission pattern and population genetic characteristics of the parasite are valuable for the prevention and control of thelaziasis in animals and humans [ 12 ].…”

The new cases of thelaziosis on the Balkan Peninsula

“…The first autochthonous case of thelaziosis O n L i n e F i r s t in Greece was described in a dog living in a northern area of the country (Diakou et al, 2015). Later, additional cases have been reported in animals from north-central Greece (Papadopoulos et al, 2018). Although to date there have been no further reports of cases in Greece, anecdotal reports from vets (through personal communication or in social media) indicate that the infection is more common than previously evidenced (Diakou, unpublished data).…”

Systematic review on infection and disease caused byThelazia callipaedain Europe: 2001–2020

“…Nevertheless, at the end of the 20th century, autochthonous cases were reported in Italy [50,52] and, since then, T. callipaeda has increasingly been reported in some European countries both in animals and humans [75]. In Europe, the intermediate host of this eyeworm is the male drosophilid fruit fly Phortica variegata Fallén, 1823 (Drosophilidae, Steganinae), which feeds on lachrymal secretions of mammals [53,55,58,60].…”