First report of human Thelazia callipaeda infection in Portugal.

The zoonotic parasitic nematode Thelazia callipaeda, also known as the oriental eye worm, is endemic in several European countries, including Portugal. Infections may result in ocular disease in domestic and wild animals as well as humans, with more or less severe manifestations. We report the first human case of ocular thelaziosis by T. callipaeda in Portugal, a country where the parasite had already been found to infect dogs, cats, red foxes, wild rabbits and a beech marten. An 80-year-old patient from east-central Portugal, who had been suffering from tearing for a few years, had whitish filiform fragments removed from the left eye. Polymerase chain reaction of partial cytochrome c oxidase subunit 1 and 18S small subunit rRNA genes followed by bidirectional sequencing and BLAST analysis confirmed T. callipaeda haplotype 1, the only haplotype previously reported in Europe. The endemicity of T. callipaeda in domestic and wild animals in east-central Portugal makes it very likely that infection of the human patient had occurred locally. In east-central and other geographical areas of Portugal, veterinarians and physicians, especially ophthalmologists, should regard T. callipaeda as a cause of ocular pathology in animals and humans.

Thelazia callipaeda in Slovakia - From sporadic cases to endemic areas.

Spirurid nematode Thelazia callipaeda, transmitted by the fruit fly Phortica variegata, is a causative agent of an ocular parasitic disease called also canine thelaziosis. Dogs, cats, and wild canids are considered the primary definitive hosts for the parasite, but humans may also serve as aberrant definitive hosts. For long decades the geographic range of T. callipaeda was strictly limited to the territory of Asia, but after the year 2000, the parasite began to spread rapidly through Europe. The first autochthonous infections of dogs and foxes in Slovakia were recorded in 2016. In the present study, the results of a whole-area surveillance for canine thelaziosis are reported. Altogether, 142 cases of infection caused by T. callipaeda were diagnosed by veterinarians in dogs between 2016 and the first quarter of 2021, and two cases of feline thelaziosis were recorded. The majority of the dogs showed mild ocular signs manifested by conjunctivitis; 8.5% of them suffered from more serious mucopurulent discharge, and in two dogs corneal ulceration was recorded. The screening revealed increasing trends in the occurrence of canine thelaziosis from both a temporal and spatial point of view and unambiguously confirms the endemic status of T. callipaeda in Slovakia with the prospect of its further expansion.

Morphological and molecular characterization of Spirocerca lupi (Nematoda: Spirocercidae) from domestic dogs in Vietnam with reference to Spirocerca vulpis.

Spirocerca lupi is a common parasitic nematode associated with esophageal cancer of canids. Recent surveys have revealed an increasing number of canids infected with Spirocerca spp. in Africa, the Americas, Europe and Western Asia, and described a new species, Spirocerca vulpis, from red foxes (Vulpes vulpes). However, in Southeast Asia, research on Spirocerca spp. is scarce. Therefore, the aim of this study is to explore Spirocerca infection in domestic dogs in Vietnam and to identify the Spirocerca species by analyzing their morphometric and molecular data. We found Spirocerca spp. specimens in 51 (17.7%) out of 287 dogs examined with the intensity of infection ranging from one to 29 nematodes per dog. These nematodes were morphologically and molecularly identified as S. lupi. For morphology, the presence/absence of teeth, the ratio of glandular to muscular esophagus lengths, and the position of the vulva opening of S. lupi and S. vulpis varied between reports, suggesting caution in identification of Spirocerca species based exclusively on morphological characteristics. The molecular analysis based on a partial cox1 sequence revealed that S. lupi from Vietnam is genetically close to those from India and China, but far different from those of Israel, South Africa, Peru and Hungary. Given high genetic and morphological variations, more extensive surveys on Spirocerca spp. from various mammalian hosts at a greater scale are necessary to elucidate the divergence of this nematode.

A Helminth Survey of Northern Bobwhite Quail (Colinus virginianus) and Passerines in the Rolling Plains Ecoregion of Texas.

The Northern bobwhite quail (Colinus virginianus) is a popular game bird that has been experiencing a well-documented decline throughout Texas since the 1960s. While much of this decline has been attributed to habitat loss and fragmentation, recent studies have identified other factors that may also contribute to decreasing quail populations. Parasites, in particular, have become increasingly recognized as possible stressors of quail, and some species, particularly the eyeworm (Oxyspirura petrowi) and cecal worm (Aulonocephalus pennula) are highly prevalent in Texas quails. Eyeworm infection has also been documented in some passerines, suggesting helminth infection may be shared between bird species. However, the lack of comprehensive helminth surveys has rendered the extent of shared infection between quail and passerines in the ecoregion unclear. Thus, helminth surveys were conducted on bobwhite, scaled quail (Callipepla squamata), Northern mockingbirds (Mimus polyglottos), curve-billed thrashers (Toxistoma curvirostre), and Northern cardinals (Cardinalis cardinalis) to contribute data to existing parasitological gaps for birds in the Rolling Plains ecoregion of Texas. Birds were trapped across 3 counties in the Texas Rolling Plains from March to October 2019. Necropsies were conducted on 54 individuals (36 quail and 18 passerines), and extracted helminths were microscopically identified. Nematode, cestode, and acanthocephalan helminths representing at least 10 helminth species were found. Specifically, A. pennula and O. petrowi had the highest prevalence, and O. petrowi was documented in all of the study species. This research adds to the body of knowledge regarding parasitic infections in quail and passerines of the Rolling Plains ecoregion and highlights the potential consequences of shared infection of eyeworms among these bird species.

[Ocular thelaziosis in a dog in Germany - an autochthonous case?] / Okuläre Thelaziose bei einem Hund in Deutschland ­ ein autochthoner Fall?

Thelazia callipaeda is a vector-borne nematode transmitted by Phortica spp. (fruit flies) and one of the causes of mild to severe conjunctivitis and keratitis in dogs, cats, rabbits and humans. It has been formerly known as the oriental eye worm based on its geographic occurrence. By now, it has been shown to be endemic in several southern and eastern European countries as well as extending its geographic distribution further throughout Europe. In the present case report, T. callipaeda infection was diagnosed in a female dog from Germany. The dog was referred by a local veterinarian due to a treatment-resistant conjunctivitis. A comprehensive ophthalmologic examination revealed 3 adult eye worms in the conjunctival sac as well as on the bulbar side of the nictitating membrane of the left eye. These were identified by morphological features and molecular techniques as T. callipaeda and represented the primary cause of the dog's unilateral blepharospasm, hyperemic conjunctiva and epiphora. Treatment consisted of manual collection of the adult worms and the administration of moxidectin/imidacloprid as spot on (Advocate®, Bayer). All clinical signs resolved within one week after treatment. In Germany, ocular thelaziosis still represents a rare disease. Usually, it is diagnosed in cats and dogs either imported from abroad or accompanying the owners on holiday travels to endemic countries. The dog presented in this case report was born in Germany. Except for a one-week stay in the Netherlands 11 months before the symptoms began, it had never traveled abroad. Considering the prepatency of T. callipaeda, an autochthonous transmission in this case is highly probable.

A first report of Thelazia callipaeda infection in Phortica okadai and wildlife in national nature reserves in China.

BACKGROUND: Thelazia callipaeda is a zoonotic parasitic nematode of the family Thelaziidae, with Phortica okadai as its intermediate host and only confirmed vector in China. China has the largest number of human cases of thelaziosis in the world. It is generally believed that infected domestic animals (dogs and cats) are the most important reservoir hosts of T. callipaeda, and thus pose a direct threat to humans. At present, there is little research or attention focused on the role of wildlife in the transmission cycle of thelaziosis in nature reserves. METHODS: We selected locations in four national nature reserves across China to monitor P. okadai and wildlife. We used a fly-trap method to monitor P. okadai density. Morphological analysis of the parasites collected from the conjunctival sac of the infected wildlife was undertaken as the first step in species identification, and polymerase chain reaction (PCR) was used for species confirmation. RESULTS: In 2019, the density of P. okadai in Foping National Nature Reserve in China increased sharply, and infected P. okadai were newly found in the reserve. Giant panda, wild boar, leopard cat, and black bear were found to be newly infected with T. callipaeda (one individual of each species). A total of four worms were collected, one from each species of wildlife. The four worms were identified as T. callipaeda by their morphological characteristics; species identification was confirmed by PCR amplification. CONCLUSIONS: To the best of our knowledge, this is the first report of T. callipaeda infection in P. okadai as well as in a variety of wildlife, including giant panda, in nature reserves in China. These results indicate that there is a transmission cycle of T. callipaeda among wildlife in these nature reserves. The increasing number of case reports of thelaziosis in wildlife suggest a likely risk of T. callipaeda infection for the inhabitants of villages situated around nature reserves.

Threat of exotic worms in dogs imported from Romania.

More and more dogs are legally entering the UK from overseas, bringing with them the risk of importing unusual parasites, some of which are zoonotic. Here, Ian Wright and colleagues describe three cases of parasitic worms found in Romanian dogs.

Suspected autochthonous Thelazia callipaeda infection in a dog in northern Germany.

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.

A human corneal ulcer caused by Thelazia callipaeda in Southwest China: case report.

In this study, we describe a rare human case with corneal ulcer caused by thelaziosis in a 69-year-old man in Southwest China. A male nematode was discovered and removed from the patient's right eye with a long spicule and further identified by sequencing mitochondrial cox1 gene. The ophthalmologic and molecular biological evidence demonstrates the corneal ulcer caused by T. callipaeda infection, which is mainly distributed in Asian and European countries. Most T. callipaeda infections are emerged in the conjunctiva, leading to conjunctivitis. To the best knowledge of the authors, corneal ulcers caused by T. callipaeda have not been reported yet.

First report of Spirocerca vulpis in red foxes (Vulpes vulpes) in Portugal.

Recent studies have described Spirocerca lupi-like nematodes in the stomach of red foxes (Vulpes vulpes) in Europe. A phylogenetic analysis of those specimens using mitochondrial DNA and their morphological reexamination allowed their characterization as a different species, Spirocerca vulpis. Between the years of 2010 and 2017, roundworms were collected from seven red foxes of northeastern Portugal found at necropsy with nodular lesions on their stomach wall. Histopathological analysis of four foxes revealed granulomatous lesions of the gastric nodules. On morphological assessment, by light microscopy, nematodes revealed the presence of six triangular teeth-like buccal capsule structures, which are absent in S. lupi. Polymerase chain reaction was run to amplify a 551 bp partial fragment of the cytochrome c oxidase subunit 1 gene. Sequences were 99% similar to S. vulpis (85% coverage) of red foxes from Spain and Bosnia and Herzegovina, 99% similar (99% coverage) to sequences of Spirocerca sp. of red foxes from Denmark and 93% similar (99% coverage) to S. lupi from South Africa. This is the first report of S. vulpis in foxes or any other host from Portugal.

Ophthalmic Thelazia callipaeda infections: first feline and new canine imported cases in Germany.

The first case of feline ocular Thelazia callipaeda infection and two new canine imported infections in West Germany are here described. The three animals had a history of recent travel to/from other countries. The young adult cat imported from Spain presented an intermittent unilateral ocular discharge. During in-depth ophthalmic examination, a single alive nematode was removed from the conjunctival compartment of the affected eye. Referring to the canine cases, an adult female dog originated from Kenya presented epiphora and mucous whitish-grey discharge of the right eye. During flushing of the nasolacrimal duct two small, thin and long nematodes were removed. Furthermore, a male Borzoi racing dog with regular visit to racing tracks in different countries presented ocular mucous discharge. At ophthalmologic examination, two transparent-whitish vital nematodes were removed. All nematode specimens of the three cases were morphologically identified as adult T. callipaeda parasites. The animals were treated orally with milbemycin oxime (2.0 mg/kg; cat) or milbemycin oxime/praziquantel (0.5 mg/kg and 5.0 mg/kg; dogs) twice with 1-week interval resulting in complete resolution of symptoms. The repeated introduction of patent T. callipaeda-infected animals, especially from southern and eastern endemic countries, will ease the establishment of ophthalmic thelaziosis in Northern Europe. The male fruit fly, Phortica variegata, an intermediate host of T. callipaeda, is endemic within European countries. Considering the clinical and zoonotic relevance of ophthalmic thelaziosis, enhanced disease awareness of European medical and veterinarian doctors and in-depth eye examination for proper detection of T. callipaeda are crucial for appropriate anthelmintic treatments and to limit spreading of the infection.

Unravelling Spirocerca vulpis from red foxes from Switzerland: a 20-year-old record.

Spirocerca vulpis is a parasitic nematode of red foxes associated with gastric nodule formation. Since its description in 2018, this species has been reported in red foxes from Spain, Bosnia and Herzegovina, Italy, and Portugal. We present here the analysis of uncharacterized nematodes obtained from gastric nodules of a red fox from Switzerland in 1999. The specimens were identified as S. vulpis based on the observation of teeth-like structures in the buccal capsule and a 99.4% sequence identity to S. vulpis DNA from Spain. Phylogenetic analysis demonstrated the clustering of the Swiss sequences in a different group from specimens of other geographical locations. Altogether, this study constitutes the first report of S. vulpis in Switzerland and a report of the oldest specimen of this species in the world. Our findings highlight the widespread distribution of S. vulpis in Europe which may be facilitated by the free-roaming nature of red foxes.

First report of Thelazia callipaeda in a free-ranging Iberian wolf (Canis lupus signatus) from Spain.

Thelazia callipaeda (Spirurida, Thelaziidae) is a vector-borne zoonotic eyeworm able to infect a broad spectrum of carnivores. Here, we describe the first case of bilateral infection by T. callipaeda in the eyes of an adult female Iberian wolf (Canis lupus signatus) in central Spain. Nematodes collected were morphologically identified (n = 42), and two specimens were molecularly characterized. At the sequence analysis of the partial mitochondrial cytochrome c oxidase subunit 1 gene, T. callipaeda haplotype 1 (the only haplotype circulating in Europe) was detected. The role of the Iberian wolf as a natural reservoir for T. callipaeda in the life cycle of this emerging zoonosis and the implications in conservation are discussed.

Canine thelaziosis in the Czech Republic: the northernmost autochthonous occurrence of the eye nematode Thelazia callipaeda Railliet et Henry, 1910 in Europe.

The eye nematode Thelazia callipaeda Railliet et Henry, 1910 (Spirurida: Thelaziidae) is a vector-borne zoonotic nematode infecting a range of wild and domestic carnivores as well as humans. It is considered to be a causative agent of emerging and neglected disease and currently invades central part of Europe. Nematodes were collected from the eye of a dog living in Prague, which never travelled outside the Czech Republic. The nematodes were identified based on their morphology and partial sequence of the cox1 gene as T. callipaeda haplotype 1. This finding represents the northernmost record of autochthonous canine thelaziosis in Europe. The insufficient control of imported animals as well as free movement of dogs and wild carnivores within Europe probably facilitates spreading of T. callipaeda throughout the continent. To better understand the spreading of T. callipaeda and to prevent its zoonotic transmissions, information about the risk of this infection in newly invaded countries should be disseminated not only among veterinarians and physicians, but also within the community of pet owners and hunters.

A Case of Human Thelaziasis and Review of Chinese Cases.

PURPOSE: Human cases of thelaziasis caused by Thelazia callipaeda have increased in China in recent years. Although this species is of medical importance, our knowledge about the epidemiology of thelaziasis is still fragmentary. This study first reports a case of thelaziasis in central China. Then, the epidemiology of thelaziasis in China in the past 100 years (1917-2018) is reviewed. METHODS: A 5-year-old girl experienced discomfort in her left eye. Four thread-like worms were seen in the nasal upper eyelid of the left eye. The symptoms disappeared after these parasites were removed. In addition, we reviewed studies of Chinese human thelaziasis cited in articles or book chapters in all languages from inception to 31 Dec 2019. RESULTS: China is the nation with the most reports of thelaziasis (653 cases) in the world. More human cases were reported in central and eastern China than in other areas, and the majority of cases were from rural areas in poor socioeconomic settings. CONCLUSION: Special attention should be paid to this neglected disease in China. The use of a One Health approach is imperative for preventing eyeworm infections in humans.

Molecular Identification of Oxyspirura Petrowi Intermediate Hosts by Nested PCR Using Internal Transcribed Spacer 1 (ITS1).

Recently, the heteroxenous eyeworm, Oxyspirura petrowi, has gained attention due to its prevalence in the declining game bird, Northern bobwhite (Colinus virginianus), but the intermediate hosts of many nematodes remain unknown. However, identifying the intermediate host of O. petrowi with traditional techniques would be difficult and time-consuming, especially considering there are more than 80 potential orthopteran hosts just in Texas. To screen a large number of samples quickly and effectively, primers for nested PCR (nPCR) were developed using the internal transcribed spacer 1 (ITS1) region. Then the nPCR was used to identify which of the 35 species collected from the Order Orthoptera were potential intermediate hosts of O. petrowi. With this technique, 18 potential intermediate hosts were identified. Later, we collected live specimens of species that tested positive to confirm the presence of larvae, but larvae were not found in the live specimens, nor in the extra tissue of the species that had tested positive for O. petrowi DNA. Despite this, this study demonstrated that nPCR is more sensitive than traditional techniques and can be a valuable tool in determining the intermediate hosts of parasites.

Case Report: Thelazia callipaeda Eye Infection: The First Human Case in Germany.

Thelazia callipaeda eye worm is a nematode transmitted by drosophilid flies not only primarily to carnivores and lagomorphs but also to humans. Only a few cases have been reported in Europe (Italy, France, and Portugal). Here, we report the first eye infection in a German patient.

Occurrence, prevalence, and explanatory environmental variables of Spirocerca vulpis infestation in the foxes of western Spain.

The main aim of this study was to not only establish the prevalence of the recently described Spirocerca vulpis parasite in the wild-life cycle of carnivores in western Spain but to also elaborate a model to explain the risk of infestation based on 16 topo-climatic and habitat variables. During the period from June 2016 to November 2017, 1644 carcasses of red foxes (Vulpes vulpes) and another 105 wild mammals, legally hunted or killed in car accidents, were analyzed. Parasitic nodules of Spirocerca were found in 6% of the foxes, and the molecular analyses established a homology of our samples with the species S. vulpis. There were no differences in the occurrence of the infestation between sexes, but there were differences in terms of age, such that infestation was proportionally more frequent among young individuals. In terms of temporality, a higher percentage of positive cases was observed during the late-autumn and winter months, especially between December and February. This study provides new data on the factors that predispose S. vulpis infection in the red fox. Model results indicate that a spatial pattern exists in the occurrence and prevalence of this species in the studied area (higher probabilities to the west), and that this pattern seems to mainly be associated with topo-climatic variables.

Aberrant Mesenteric Migration of Spirocerca lupi Larvae Causing Necrotizing Eosinophilic Arteritis, Thrombosis, and Intestinal Infarction in Dogs.

This report presents a novel canine condition in 32 dogs in which aberrant migration of Spirocerca lupi larvae through mesenteric arteries, instead of gastric arteries, led to small or large intestinal infarction. This form of spirocercosis was first recognized in Israel in 2013 and is currently ongoing. Typical clinical signs were anorexia and weakness of 3 to 4 days and, less frequently, vomiting and diarrhea, followed by collapse, bloody diarrhea, and severe vomiting. Exploratory laparotomy showed 1 or more infarcted and often perforated intestinal segments in all cases. Microscopically, there was intestinal mucosal to transmural coagulative necrosis and mesenteric multifocal necrotizing eosinophilic arteritis, thrombosis, hemorrhage, and early fibroplasia. Third-stage S. lupi larvae were identified by morphologic features in 9 of 32 (28%) cases, and the species was confirmed by polymerase chain reaction in 4 cases. Nearly 50% of the dogs had been receiving prophylactic therapy, which did not prevent this form of spirocercosis.

First report of canine ocular thelaziosis in the Republic of Moldova.

BACKGROUND: Countries of eastern Europe are considered, due to several risk factors, more vulnerable to infections with newly (re)emerging pathogens. During the last decade, in several European countries, reports of autochthonous cases of ocular thelaziosis due to Thelazia callipaeda have been published, posing a great concern from both veterinary and public health perspective. However, in the Republic of Moldova only limited epidemiological data are available regarding zoonotic vector-borne pathogens and, until now, no data exist on the zoonotic nematode T. callipaeda. METHODS: In September 2018, an 11-year-old dog, mixed-breed, intact male was referred to a private veterinary clinic from Chișinau, Republic of Moldova, with a history of 2 weeks of an ocular condition affecting the right eye. The ophthalmological exam revealed the presence of nematode parasites in the conjunctival sac and under the third eyelid. The collected parasites were identified by morphological techniques and molecular analysis. RESULTS: A total of 7 nematodes were collected, and 5 females and 2 males of T. callipaeda were identified morphologically. The BLAST analysis confirmed the low genetic variability of this parasite in Europe. The travel history of the patient allowed us to confirm the autochthonous character of the case. CONCLUSIONS: To the best of our knowledge, this is the first report of thelaziosis in dogs from the Republic of Moldova, which confirms the spreading trend of T. callipaeda and the existence of an autochthonous transmission cycle of this zoonotic parasite in the country.