Figure - available from: Parasites & Vectors
This content is subject to copyright. Terms and conditions apply.
Thelazia callipaeda nematodes recovered from the European badger, Meles meles. a Anterior extremity, buccal capsule and mouth opening with a hexagonal profile, transversally serrated cuticle. b Posterior extremity of male. c Gravid female, vulva located anterior to the oesophago-intestinal junction. d Gravid female, larvae inside the uterus
Source publication
Background:
Thelazia callipaeda (Spirurida, Thelaziidae) is a vector-borne zoonotic eye worm with a broad host spectrum. In Europe, it is an emerging threat, having greatly expanded its geographical distribution during the past two decades. In Romania, T. callipaeda has been previously reported in domestic and wild canids and felids. The aim of th...
Similar publications
Citations
... Thelazia callipaeda Railliet & Henry, 1910, or the oriental eye worm, is the causative agent of an important emerging zoonosis reported mainly in Asia, Central and southern Europe (do Vale et al. 2020), and more recently also in the USA (Schwartz et al. 2021). The main definitive hosts are considered to be the wild and domestic canids, although the species was identified also in wild and domestic felids (Mihalca et al. 2016;do Vale et al. 2020;Jin et al. 2021), mustelids (Otranto et al. 2009;Ionică et al. 2019), ursids (Jin et al. 2021;Papadopoulos et al. 2022), wild boars (Jin case of T. callipaeda infection in a lion (Panthera leo) from a zoo in Romania. ...
... database. For Thelazia positive locations, one symbol for each animal species from each county was placed based on previous reports reviewed in Ionică et al. (2019)and Cotuțiu et al. (2022). ...
Thelazia callipaeda, the zoonotic “oriental eye worm”, is an emerging nematode known to infect a wide range of hosts, particularly carnivores (wild and domestic canids and felids, mustelids, and ursids), but also other mammal groups (suids, lagomorphs, monkeys, and humans), across a wide geographical area. New host-parasite associations and human cases have mostly been reported in endemic areas. A less studied group of hosts is represented by zoo animals that may harbor T. callipaeda.
A 23-year old male lion (Panthera leo) that was born in a public zoo in Reșița (Caraș-Severin County, Romania) was submitted to the University of Agricultural Sciences and Veterinary Medicine of Cluj-Napoca for investigations after death from unknown reasons in November 2022. Four nematodes were collected from the right eye during the necropsy and submitted to morphological and molecular characterization.
Collected nematodes were morphologically identified as three females and one male T. callipaeda. The BLAST analysis revealed 100% nucleotide identity to numerous isolates of T. callipaeda haplotype 1.
The present paper presents a new host-parasite association between T. callipaeda and P. leo from a zoo in Romania.
... Not surprisingly, canine thelaziosis is considered an emerging vector borne helminth with significant zoonotic potential. The reason why it has emerged, and continues to do so, in Europe is not clear but may be associated with the increasing importance of wildlife, such as the fox, but also animals such as bears and wolves (Papadopoulos et al., 2021) and mustelids (Ionică et al., 2019) in maintaining infection in their natural habitats which increasingly encroach into domestic environments. Another zoonotic filarial nematode, Brugia malayi, has re-emerged in Sri Lanka after a quiescent period of four decades with dogs and cats the potential reservoirs for human infections (Mallawarachchi et al., 2018). ...
Helminth zoonoses remain a global problem to public health and the economy of many countries. Polymerase chain reaction-based techniques and sequencing have resolved many taxonomic issues and are now essential to understanding the epidemiology of helminth zoonotic infections and the ecology of the causative agents. This is clearly demonstrated from research on Echinococcus (echinococcosis) and Trichinella (trichinosis). Unfortunately, a variety of anthropogenic factors are worsening the problems caused by helminth zoonoses. These include cultural factors, urbanization and climate change. Wildlife plays an increasingly important role in the maintenance of many helminth zoonoses making surveillance and control increasingly difficult. The emergence or re-emergence of helminth zoonoses such as Ancylostoma ceylanicum, Toxocara, Dracunculus and Thelazia exacerbate an already discouraging scenario compounding the control of a group of long neglected diseases.
... Although mustelids have a wide distribution in Europe and are in close contact with domestic animals, parasitological studies of these animals are limited and most of the time include incidental findings. In the last decade, some zoonotic and emerging diseases were detected for the first time in mustelid species [280,281], including the invasive species Neogale vison [282]. The absence of relevant studies in some countries could be related to a low research interest in this animal family or to the legally protected status of many mustelids. ...
... Badgers are mostly nocturnal animals, thus not regularly exposed to the fruit fly vector of the eye worm T. callipaeda [79]. Nevertheless, the parasite was found in 1.8% of the examined badgers in Romania, confirming this animal species as a suitable host [280]. However, given the rarity of T. callipaeda in mustelids evidenced so far, the infection can be considered opportunistic in these animals in endemic areas. ...
... Thelazia callipaeda, Capillaria aerophila and Trichinella spp.: Beech Martens are Additional Hosts of These Important Parasites Studies on T. callipaeda in the abundant group of mustelids are still limited with scarce information on their role as reservoir hosts for this parasite [280,333]. In Europe, infection with T. callipaeda in beech martens was documented in Italy (13.60%) [79], Portugal (one case report) [334], and Romania (7.69%) [280]. ...
Mesocarnivores are small-or mid-sized carnivore species that display a variety of ecologies and behaviours. In Europe, wild mesocarnivores are represented by the red fox (Vulpes vulpes), the golden jackal (Canis aureus), the European wildcat (Felis silvestris), the Mustelidae of the genera Meles, Martes, Mustela, Lutra, the invasive species of raccoon dog (Nyctereutes procyonoides), raccoons (Procyon lotor), and American mink (Neomustela vison). These abundant animals thrive in various habitats and often develop their activity close to human settlements. Thus, they may play an important role in the introduction, maintenance, and transmission of major parasitic zoonoses and promote bridging infections with domestic animals. Against this background, this article reports and discusses some of the most important endoparasites of wild mesocarnivores living in Europe, on the basis of their actual role as reservoirs, spreaders, or sentinels. The data derived from epizo-otiological studies in different European countries, and the proven or speculated implications of the detected endoparasites in human and domestic animals' health, are discussed. Through older and recent literature review, the state-of-the-art knowledge on the occurrence and prevalence of the parasites under consideration is presented, showing further, warranted investigations and the need for surveillance and vigilance.
... In Romania, Thelazia spp. were so far found in domestic and wild carnivores [7][8][9][10] and cattle [6,11]. ...
Background
Equine thelaziosis is a neglected vector-borne parasitic disease in modern veterinary medicine, lacking recent reports. It is transmitted by Musca autumnalis, and potentially other Muscidae species, by ingesting the lachrymal secretions of its equine host. The distribution of both Thelazia lacrymalis and its intermediate hosts remains largely unknown throughout Europe, with most studies dating back 20 years. The aim of this study was to assess the presence, prevalence and distribution of T. lacrymalis in horses from Romania.
Methods
The eyes of 273 horses, slaughtered at two abattoirs from the Northwestern and Western regions of Romania, were examined for the presence of T. lacrymalis between March and November 2021. Upon detection, the nematodes were collected and morphologically identified using the keys from literature. Following identification, one specimen from each animal was selected for molecular analysis while the rest underwent detailed morphometric measurements. Mapping and distribution, according to ecoregions, was done using the QGis 3.20 software, while sequences obtained were compared to those available in GenBank through BLAST analysis using the MEGA X software.
Results
Of the 273 animals sampled, 12 (4.39%) were positive for Thelazia spp. infection. Eighty-seven nematodes were recovered, all morphologically identified as T. lacrymalis. The intensity of infestation varied between one and 33 nematodes/animal while five animals presented a bilateral infestation and seven a unilateral one. The highest prevalence was encountered in Pannonian ecoregion (12.12%) while the lowest was in the Alpine ecoregion (0%). Seventy-five intact specimens underwent detailed morphometric analysis, of the 18–20 parameters, resulting in notable differences in striation lengths compared to the data available in other reports. BLAST analysis identified a 96.46–98.60% similarity to the only other COI gene sequence available for T. lacrymalis.
Conclusions
The current study represents the first report of T. lacrymalis in horses in Romania. The low prevalence rates are probably linked to the wide use of macrocyclic lactones.
Graphic Abstract
... In Romania, the disease was first diagnosed in 2014 [10], in a domestic dog from the western part of the country. Subsequent surveillance documented the spread across most of Romania's territory, in a wide variety of hosts: domestic dogs [11][12][13], domestic cats [13], jackals, wolves, wildcats [14], foxes [15], and mustelids [16]. However, despite its wide distribution in animals, no human cases have been documented in Romania, so far. ...
Thelaziosis caused by Thelazia callipaeda is an emerging disease in Europe. Only two reports of naturally infected lagomorphs have been published so far. The aim of this study was to evaluate the status of the Romanian populations of European brown hares, Lepus europaeus as reservoir hosts for T. callipaeda. Between November 2019 and November 2021, the eyes of 326 L. europaeus carcasses were examined for the presence of ocular parasites. Nematodes were stored in plastic vials with physiological saline, followed by morphological and molecular identification. QGis 3.20 and EpiInfoTM 7 were used for mapping and statistical analysis. Four (1.23%) hares harbored T. callipaeda infection, with a total of 84 nematodes collected (mean intensity 21 nematodes/host), with 45 males, 39 females (two sexually immature, seven with only eggs, and 30 with eggs and larvae). One specimen from each host was successfully sequenced resulting in a 100% similarity with several other sequences of T. callipaeda haplotype 1. Statistical analysis revealed no significant results. The current study represents a first report of T. callipaeda in the European brown hare in Romania, and the second in Europe, also reiterating the role of lagomorphs as reservoir hosts for this zoonotic ocular nematode.
... The tail of the female was straight and that of the male was ventrally curved with several pairs of papillae in front of the anus ( Figure 5D). According to Rolbiecki [22,23], the worms were identified as T. callipaeda based on key morphological features. Four male and seven female T. callipaeda specimens were collected. ...
Human thelaziasis caused by Thelazia callipaeda is being increasingly reported worldwide. Notably, an epidemic trend is observed in Southwest China. Whether Phortica okadai found in Southwest China can act as a vector of T. callipaeda and human-derived T. callipaeda animal infections has not been widely reported. Here, P. okadai was maintained in a laboratory and experimentally infected with first-stage larvae collected from adult T. callipaeda that were isolated from infected human subjects. Dead P. okadai were subjected to PCR assay and dissected every two days to detect T. callipaeda. Subsequently, live flies were used to infect a rabbit. The infection procedures were performed once a day (20 min) for two weeks. The results show that L1 collected from the adult T. callipaeda could successfully parasitize P. okadai captured in Zunyi, a city in Southwest China, and developed into L3, and a rabbit was successfully infected with T. callipaeda using P. okadai as the intermediate host. The present study demonstrates a human-derived T. callipaeda infection in rabbits, through P. okadai, under laboratory conditions for the first time. These results provide insights into the transmission cycle of T. callipaeda and constitute a foundation to develop an effective treatment protocol for T. callipaeda infection.
... In Europe, the badger is spread over all areas, from forested regions to intensely urbanized areas [4,5]. In regards to their interaction with other species, the European badger is considered a reservoir for Mycobacterium bovis in the UK, Ireland, Spain and France [6] and they can play a role as a host for the Trichinella species [3] or Thelazia callipaeda [7]. The tympanic cavity is described as an air-filled osseous cavity carved into the temporal bone placed between the external ear and the internal ear [8,9]. ...
Given the scarce morphological data regarding the middle ear anatomy of this species, the paper attempts to describe the morphological and morphometrical data of the auditory ossicles in the badger. The study was performed using the standard morphological investigations and provides a complete morphological description of the ossicular assembly (malleus, incus and stapes) with some comparative features and attempts to provide a complete set of standardized metrical data for each ossicle. A more-detailed attempt to compare some functional aspects in the light of combined metrical ratios is also implied.
... The tail of the female was straight and that of the male was ventrally curved with several pairs of papillae in front of the anus (Fig. 5d). The worms were identi ed as T. callipaeda based on the key morphological features described by Rolbiecki [22,23]. Four male and seven female T. callipaeda specimens were collected. ...
Background: Human thelaziasis caused by Thelazia callipaeda (Spirurida, Thelaziidae) is being increasingly reported worldwide. Notably, it shows an epidemic trend in Guizhou Province, Southwest China. Whether Phortica okadai distributed in Southwest China can act as a vector of T. callipaeda and human-derived T. callipaeda animal infections have not been widely reported, there is also limited literature on animal models with T. callipaeda infection.
Methods: T. callipaeda was isolated from cases of human infection and identified by morphological and molecular analyses. P. okadai was cultured in a laboratory and experimentally infected with first-stage larvae (L1) collected from adult worms. Dead P. okadai were subjected to PCR assay and dissected every two days to detect T. callipaeda. Live flies were then used to infect a rabbit using a special device. The infection procedures were performed once a day (20 min) for two weeks. The infected rabbit was examined every two days for worms in the eyes.
Results: The nematode causing parasitic infection in the patient's eyes was identified as T. callipaeda. L1 collected from adult T. callipaeda successfully parasitized P. okadai captured in Zunyi, a city in Southwest China, and developed into L3. Experimentally infected P. okadai, as a vector of T. callipaeda, could then be used to transmit L3 to rabbits. A rabbit was successfully infected with T. callipaeda using P. okadai as the intermediate host.
Conclusions: The present study demonstrates a human-derived T. callipaeda infection in rabbits, through P. okadai, under laboratory conditions for the first time. These results indicate that there is a transmission cycle of T. callipaeda and suggest a likely epidemic risk due to an increasing trend of this zoonotic nematode in southwest China.
... red foxes, beech martens, wolves and badgers) and lagomorphs (e.g. hares and wild rabbits) (Dumitrache et al., 2018;Gama et al., 2016;Ionicȃ et al., 2019;Mihalca et al., 2016;Otranto et al., 2007Otranto et al., , 2009Otranto & Dantas-Torres, 2015). This is further supported by the cases in areas with no reports of infested domestic animals, where the role of wild carnivores in introducing, maintaining and spreading this nematode was crucial (Otranto & Dantas-Torres, 2015). ...
Thelazia callipaeda (Spirurida, Thelaziidae) eyeworm, a zoonotic parasite transmitted by lachryphagus drosophilids, causes subclinical to clinical ocular disease in a wide range of animal species, including humans. In the past 20 years, the infection spread where the vector thrives, being endemic in many European countries. Recently, the infestation has been reported also in the United States. Here, we describe the first records of the brown bear (Ursus arctos) as a host of T. callipaeda. Eight (26.7%) out of 30 bears were found to be infested with T. callipaeda adult worms. In addition, the parasite was detected in 13 wolves (Canis lupus) sharing the same environment with the brown bears. At the molecular characterization all nematodes belonged to the haplotype 1, which is the only one recorded in Europe, as yet. This finding demonstrates that brown bears may act as hosts for this parasite suggesting its potential role in the maintenance of the cycle not only in the wild, but also in captivity. Under the above circumstances, brown bears may represent potential zoonotic risks for humans both in rural and in urban areas where other reservoirs may be infected.
This article is protected by copyright. All rights reserved
... [Baron] Cuvier, 1823 [21][22][23][24][25][26]. However, T. callipaeda has been reported also in other mammals, including the European rabbit Oryctolagus cuniculus (Linnaeus, 1758), the brown hare Lepus europaeus Pallas, 1778 [27,28] and, above all, in humans [1,3,4,11,14]. ...
Thelazia callipaeda is a zoonotic nematode transmitted by drosophilid flies. It causes ocular thelaziosis, a disease of carnivores, such as dogs, cats, and foxes, and also humans. The parasite has thus far been observed in various areas of Eurasia, including 20 countries within Europe. The present study documents its presence in the south-east region of Poland, near the Ukraine border. An adult nematode was removed from the conjunctival sac of a dog showing ocular inflammation and purulent discharge. The dog’s precise origin is unknown. Based on its localization and morphometrical features, the nematode was identified as a Thelazia callipaeda adult male. The present study is the first report of T. callipaeda in a dog in Poland.
