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

Abstract

Cases of thelaziosis by Thelazia callipaeda have been increasing considerably in Europe throughout the 21st century, with recent emphasis on Eastern Europe. A systematic review was conducted using defined search terms across three major databases and, additionally, with the examination of the references of the 56 articles selected. Available information about epidemiological and clinical features of all cases of thelaziosis by T. callipaeda in companion animals, wildlife and humans was extracted, evaluated and subjected to qualitative and quantitative analysis. In all cross-sectional studies about dogs, cats and red foxes, males were more frequently infected than females (dogs: p = 0.0365; cats: p = 0.0164; red foxes: p = 0.0082). Adult dogs seem to be more prone to infection (p < 0.0001), as well as large-sized dogs (p < 0.0001), and companion animals that live exclusively outdoors (p < 0.0001). Dogs and red foxes involved in these cross-sectional studies harboured significantly more female than male nematodes (p < 0.0001). Thelaziosis by T. callipaeda is far from controlled in Europe. Only through updated epidemiological data, knowledge improvement and awareness can correct diagnosis and appropriate treatment and prevention be ensured to tackle this zoonosis.

The Vector-Borne Zoonotic Nematode Thelazia callipaeda in the Eastern Part of Europe, with a Clinical Case Report in a Dog in Poland

“…Therefore, it has been predicted that Poland lies within the range of T. callipaeda [ 37 ]. Undoubtedly, an indication for this were the findings of T. callipaeda in the neighboring countries, i.e., Germany, the Czech Republic, and Slovakia [ 15 ] ( Figure 1 ). Out of four records from Germany, two describe cases that are probably introduced [ 15 ].…”

“…Undoubtedly, an indication for this were the findings of T. callipaeda in the neighboring countries, i.e., Germany, the Czech Republic, and Slovakia [ 15 ] ( Figure 1 ). Out of four records from Germany, two describe cases that are probably introduced [ 15 ]. However, cases described from Slovakia [ 38 , 39 ] and from the Czech Republic [ 40 ] are autochthonous.…”

“…In recent years, an increased number of T. callipaeda infection clinical cases have been observed throughout Europe ( Figure 1 ) [ 4 , 15 ]. Carnivores are considered the main definitive hosts of T. callipaeda , including domestic carnivores, such as domestic dogs or domestic cats [ 17 , 18 , 19 , 20 ], or wild carnivores, such as the red fox Vulpes vulpes (Linnaeus, 1758), the European badger Meles meles (Linnaeus, 1758), the beech marten Martes foina (Erxleben, 1777), the Eurasian lynx Lynx lynx (Linnaeus, 1758), the golden jackals Canis aureus Linnaeus, 1758, the gray wolf Canis lupus Linnaeus, 1758, the racoon dog Nyctereutes procyonoides (Gray, 1834), the sable Martes zibellina (Linnaeus, 1758), the wild cats Felis silvestris Schreber, 1777, and the Asiatic black bear Ursus thibetanus G. [Baron] Cuvier, 1823 [ 21 , 22 , 23 , 24 , 25 , 26 ].…”

“…The infection can manifest with conjunctivitis, epiphora, visual disturbances and even keratitis, and corneal ulceration (e.g., [ 3 , 4 ]). The parasite was first discovered over one hundred years ago in Punjab, India [ 5 ], and has been thus far observed in other areas of Asia, such as China, Myanmar, India, Indonesia, Thailand, Taiwan, South of Korea, Japan, Bangladesh, Nepal, Vietnam, and the former USSR [ 3 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 ], and in 20 countries in Europe [ 15 , 16 ]. Despite its wide area of distribution and significant pathogenic (including zoonotic) importance, the parasite has been identified only relatively rarely and in few localities; however, its distribution is potentially far greater, particularly since data obtained from veterinary practices are not always included in academic studies.…”

Development of Novel Management Tools for Phortica variegata (Diptera: Drosophilidae), Vector of the Oriental Eyeworm, Thelazia callipaeda (Spirurida: Thelaziidae), in Europe

“…Accordingly, the oriental eyeworm, Thelazia callipaeda Railliet & Henry, 1910, causal agent of the vector-borne zoonotic disease thelaziosis that causes different ocular lesions with variable degree of severity (including conjunctivitis, keratitis, corneal opacity, ulcers, and even blindness), has gained great attention in Europe over the last decades ( Do Vale et al 2020 , Otranto et al 2021 ). After the detection of the first case of canine thelaziosis in Italy in the late 1980s ( Rossi and Bertaglia 1989 ), as well as in foxes and cats ( Otranto et al 2003 ), the disease has spread throughout almost all mainland Europe, not only favored by pet trade ( Graham-Brown et al 2017 , Silva et al 2020 ), but also by the emergence of autochthonous foci with high infection rates ( Marino et al 2020 ).…”