Expanding the swimmer's itch pool of the Benelux: a first record of the neurotropic Trichobilharzia regenti and potential link to human infection.

BACKGROUND: Swimmer's itch, an allergic contact dermatitis caused by avian and mammalian blood flukes, is a parasitic infection affecting people worldwide. In particular, avian blood flukes of the genus Trichobilharzia are infamous for their role in swimmer's itch cases. These parasites infect waterfowl as a final host, but incidental infections by cercariae in humans are frequently reported. Upon accidental infections of humans, parasite larvae will be recognized by the immune system and destroyed, leading to painful itchy skin lesions. However, one species, Trichobilharzia regenti, can escape this response in experimental animals and reach the spinal cord, causing neuroinflammation. In the last few decades, there has been an increase in case reports across Europe, making it an emerging zoonosis. METHODS: Following a reported case of swimmer's itch in Kampenhout in 2022 (Belgium), the transmission site consisting of a private pond and an adjacent creek was investigated through a malacological and parasitological survey. RESULTS: Six snail species were collected, including the widespread Ampullaceana balthica, a well-known intermediate host for Trichobilharzia parasites. Shedding experiments followed by DNA barcoding revealed a single snail specimen to be infected with T. regenti, a new species record for Belgium and by extension the Benelux. Moreover, it is the most compelling case to date of the link between this neurotropic parasite and cercarial dermatitis. Additionally, an Echinostomatidae sp. and Notocotylus sp. were isolated from two other specimens of A. balthica. However, the lack of reference DNA sequences for these groups in the online repositories prevented genus- and species-level identification, respectively. CONCLUSIONS: The presence of T. regenti in Belgium might have severe clinical implications and its finding highlights the need for increased vigilance and diagnostic awareness among medical professionals. The lack of species-level identification of the other two parasite species showcases the barcoding void for trematodes. Overall, these findings demonstrate the need for a Belgian framework to rapidly detect and monitor zoonotic outbreaks of trematode parasites within the One Health context.

Infestação por piolhos Felicola subrostratus em felino domiciliado no município de Parnaíba, Piauí / Infestation by Felicola subrostratus in a feline domiciled in the municipality of Parnaíba, Piauí / Infestación de piojos Felicola subrostratus en felino domiciliado en el municipio de Parnaíba, Piauí

O piolho da espécie Felicola subrostratus é um inseto mastigador responsável por causar a pediculose em felinos e, apesar de ser cosmopolita, tem sua ocorrência pouco descrita na rotina clínica. A transmissão ocorre através do contato direto entre os animais ou por fômites contaminados. Os gatos parasitados podem ser assintomáticos quando em baixa parasitemia, porém em altas infestações podem apresentar prurido, alopecia, dermatites e possibilitar a ocorrência de infecções secundárias. O objetivo deste trabalho foi relatar a infestação por piolhos da espécie Felicola subrostratus em um felino domiciliado no município de Parnaíba, Piauí. O animal era um macho castrado, de dois anos de idade, sem raça definida (SRD), que foi atendido em uma clínica veterinária da cidade, apresentando como queixa principal uma dermatite por lambedura no membro posterior direito, além de prurido, alopecia, apatia, diminuição de apetite e perda de peso. No exame físico, observou-se a dermatite no membro, sendo realizado raspado cutâneo e coleta de pelos da região, verificando a presença de ectoparasitos. Os insetos foram colocados em recipientes com álcool 70ºGL e enviados ao Laboratório de Parasitologia da Universidade Federal do Piauí, que por meio da morfologia revelou ser piolhos da espécie Felicola subrostratus, confirmando o diagnóstico primário de pediculose felina, sendo essencial um diagnóstico precoce para direcionar a um tratamento adequado.(AU)

The lice from the Felicola subrostratus species is a chewing insect responsible for causing pediculosis in felines and, despite being cosmopolitan, its occurrence has been little described in the clinical routine. Transmission occurs through direct contact between animals or through contaminated fomites. The parasitized cats can be asymptomatic when in low parasitemia, but in high infestations, they can present pruritus, alopecia, dermatitis and allow the occurrence of secondary infections. The purpose of this study was to report the infestation by lice of the Felicola subrostratus species in a feline domiciled in the municipality of Parnaíba, in the state of Piauí, Brazil. The animal was a neutered male, two years old, of mixed breed, which was treated at a veterinary clinic in the city, presenting as main complaint a lick dermatitis on the right hind limb, in addition to pruritus, alopecia, apathy, decreased appetite and weight loss. On physical examination, dermatitis was observed on the limb. Skin scraping was performed and fur was collected from the region, verifying the presence of ectoparasites. The insects were placed in recipients with 70ºGL alcohol and sent to the Parasitology Laboratory at the Federal University of Piauí, which through morphology revealed to be lice of the Felicola subrostratus species, confirming the primary diagnosis of feline pediculosis, being essential an early diagnosis to guide the appropriate treatment.(AU)

El piojo de la especie Felicola subrostratus es un insecto masticador responsable de causar pediculosis en felinos y, a pesar de ser cosmopolita, su ocurrencia ha sido poco descrita en la rutina clínica. La transmisión ocurre a través del contacto directo entre animales o por fómites contaminados. Los gatos parasitados pueden ser asintomáticos cuando están en baja parasitemía, pero en altas infestaciones pueden presentar prurito, alopecia, dermatitis y permitir la aparición de infecciones secundarias. El objetivo de este trabajo fue relatar la infestación por piojos de la especie Felicola subrostratus en un felino domiciliado en el municipio de Parnaíba, Piauí. El animal era un macho castrado, de dos años de edad, sin raza definida (SRD), que fue atendido en una clínica veterinaria de la ciudad, presentando como principal síntoma una dermatitis por lamido en el miembro posterior derecho, además de prurito, alopecia, apatía. disminución del apetito y pérdida de peso. En el examen físico se observó dermatitis en la extremidad, se realizó raspado de piel y se recolectó cabello de la región, verificando la presencia de ectoparásitos. Los insectos fueron colocados en recipientes con alcohol 70ºGL y enviados al Laboratorio de Parasitología de la Universidad Federal de Piauí, que por morfología reveló ser piojos de la especie Felicola subrostratus, confirmando el diagnóstico primario de pediculosis felina, siendo fundamental un diagnóstico precoz para orientar el tratamiento adecuado.(AU)

Pelodera strongyloides in the critically endangered Apennine brown bear (Ursus arctos marsicanus).

Skin biopsies from 20 Apennine brown bears (Ursus arctos marsicanus), 17 of which displaying skin lesions, were investigated by histopathology. Different degrees of dermatitis characterized by folliculitis and furunculosis accompanied by epidermal hyperplasia and epidermal and follicular hyperkeratosis were detected. In the most severe lesions, the superimposition of traumatic wounds, probably self-induced by scratching, was observed. In 8 out of 17 (47.0%) affected bears, cross- and longitudinally-sectioned nematode larvae were present within the lumen of hair follicles, whose localization and morphological characteristics were consistent with Pelodera strongyloides. P. strongyloides is a free-living saprophytic nematode whose third-stage larvae can invade the skin causing pruritic dermatitis in several mammalian species. This is the first report of Pelodera infection in the brown bear. Although capable of causing primary dermatitis, the finding of Pelodera is not sufficient to conclude that it is the cause of the lesions observed in bears. Nevertheless, the high prevalence of the infection is indicative of a diffuse phenomenon that requires further specific investigations given the interest and conservational relevance of this relict bear population.

Severe deforming dermatitis in a kitten caused by Caryospora bigenetica.

BACKGROUND: Caryospora bigenetica is an intracellular protozoan parasite, which in its primary hosts, typically snakes, is found it the intestine. Extraintestinal multiplication with the development of tissue cysts takes place in secondary hosts, which are normally prey for snakes. Natural infection in domestic animals has been reported only in dogs; this is the first report of C. bigenetica infection in a cat. CASE PRESENTATION: A stray kitten developed nodular dermatitis after being adopted by a shelter. Firm swelling, nodules, and crusts were present mainly on the nasal bridge, eyelids, and pinnae. Histopathology and cytology revealed severe pyogranulomatous inflammation with abundant intracellular organisms suggestive of apicomplexan protozoa. Treatment with clindamycin 13 mg/kg twice daily was initiated, but the cat was euthanized because of the worsening condition. Transmission electron microscopy confirmed parasite's apicomplexan origin postmortem, and the causative agent was identified as C. bigenetica by polymerase chain reaction and DNA sequencing. CONCLUSIONS: We present the first case of a naturally occurring infection with C. bigenetica in a cat. Although the definitive etiological diagnosis relied on molecular identification, the abundance of unsporulated oocysts and caryocysts and the parasite's effective reproduction within macrophages and in several other cell types might have enabled differentiation from other protozoal infections and allowed a presumptive diagnosis through cytology and histopathology.

Evidence of a Putative Novel Species of Avian Schistosome Infecting Planorbella trivolvis.

Freshwater gastropods of the genera Lymnaea Lamarck, 1799, Physa Draparnaud, 1801, Gyraulus Charpentier, 1837, Radix Montfort, 1810, and Stagnicola Jeffreys, 1830 are considered suitable intermediate hosts for avian schistosomes. A large trematode biodiversity survey performed across 3 yr on 6 lakes in Alberta confirmed 3 already-reported snail hosts for 7 North American avian schistosomes; however, the cytochrome c oxidase subunit 1 (COI) nucleotide sequence from 1 cercarial sample (from a single specimen of Planorbella trivolvis) was distinct from all other COI schistosome sequences. As part of a simultaneous, comparable study of P. trivolvis by us in Michigan, we collected another cercarial type from 6 lakes that was 99% similar (COI) to the aforementioned cercarial type. Phylogenetic analyses of the COI and 28S rDNA genes recovered the former cercaria in a clade of avian schistosomes. In Michigan, the feces of a Canada goose (Branta canadensis Linnaeus, 1758) had a miracidium with an identical COI nucleotide sequence. Preliminary swimmer's itch and cercarial emergence studies were performed to determine if the cercariae could cause swimmer's itch and to study the emergence pattern as compared with species of Trichobilharzia Skrjabin and Zakharow, 1920.

Migratory routes, domesticated birds and cercarial dermatitis: the distribution of Trichobilharzia franki in Northern Iran.

BACKGROUND: One of the major migration routes for birds going between Europe and Asia is the Black Sea-Mediterranean route that converges on the Volga Delta, continuing into the area of the Caspian Sea. Cercarial dermatitis is a disorder in humans caused by schistosome trematodes that use aquatic birds and snails as hosts and is prevalent in areas of aquaculture in Northern Iran. Before the disorder can be addressed, it is necessary to determine the etiological agents and their host species. This study aimed to document whether domestic mallards are reservoir hosts and if so, to characterize the species of schistosomes. Previous work has shown that domestic mallards are reservoir hosts for a nasal schistosome. RESULTS: In 32 of 45 domestic mallards (Anas platyrhynchos domesticus) (71.1%), the schistosome Trichobilharzia franki, previously reported only from Europe, was found in visceral veins. Morphological and molecular phylogenetic analysis confirmed the species designation. These findings extend the range of T. franki from Europe to Eurasia. CONCLUSION: The occurrence of cercarial dermatitis in Iran is high in areas of aquaculture. Previous studies in the area have shown that domestic mallards are reservoir hosts of T. regenti, a nasal schistosome and T. franki, as shown in this study. The genetic results support the conclusion that populations of T. franki from Iran are not differentiated from populations in Europe. Therefore, the schistosomes are distributed with their migratory duck hosts, maintaining the gene flow across populations with compatible snail hosts in Iran.

TITLE: Routes migratoires, oiseaux domestiques et dermatite cercarienne : répartition de Trichobilharzia franki dans le nord de l'Iran. ABSTRACT: Contexte : L'une des principales voies de migration des oiseaux à destination et en provenance de l'Europe et de l'Asie est la route mer Noire-Méditerranée qui converge vers le delta de la Volga et se poursuit dans la région de la mer Caspienne. La dermatite cercarienne est une affection causée chez l'homme par des trématodes Schistosomatidae utilisant des oiseaux aquatiques et des mollusques comme hôtes, qui est répandue dans les zones d'aquaculture du nord de l'Iran. Avant de pouvoir lutter contre cette parasitose, il est nécessaire de connaître les agents étiologiques et leurs espèces hôtes. Ce travail vise à documenter si les canards domestiques sont des hôtes réservoirs et si oui, à caractériser les espèces de schistosomes. Des travaux antérieurs ont montré que les canards domestiques sont des hôtes réservoirs pour un schistosome nasal. Résultats : Chez 32 de 45 canards domestiques (Anas platyrhynchos domesticus) (71,1 %), le schistosome Trichobilharzia franki, précédemment signalé uniquement en Europe, a été trouvé dans les veines viscérales. L'identification de l'espèce a été vérifiée par une analyse morphologique et phylogénétique moléculaire. Cela étend l'aire de répartition de l'Europe à l'Eurasie. Conclusion : La dermatite cercarienne est répandue dans les zones d'aquaculture en Iran. Des travaux antérieurs dans la région ont montré que les canards domestiques sont des hôtes réservoirs de T. regenti, un schistosome nasal et de T. franki, comme le montre cette étude. Les résultats génétiques soutiennent que les populations de T. franki d'Iran ne sont pas différenciées des populations d'Europe. Par conséquent, les schistosomes se dispersent avec leur hôte canard lors de la migration, maintenant un flux génétique entre les populations avec des mollusques hôtes compatibles en Iran.

First case report of dermatitis associated with Leporacarus gibbus in cat.

BACKGROUND: Leporacarus gibbus is a highly specific acarian parasitizing in rabbits, with a proven zoonotic potential. While the majority of cases of L. gibbus infestation are asymptomatic, several cases of pruritic cutaneous condition in both laboratory and pet rabbits were reported. Up to date, L. gibbus has not been linked with clinical signs in any other species than rabbits and humans. CASE PRESENTATION: This case report described the clinical case of a 14-month-old cat with a dermatitis linked to L. gibbus. Mites specimens were collected by brushing, followed by light microscopy examination and species identification. To the best of our knowledge, this is the first report of L. gibbus-related dermatitis in cat. CONCLUSIONS: L. gibbus infestation should be considered as a possible differential diagnosis of pruritic skin conditions in cat.

First confirmed record of Trichobilharzia franki Müller & Kimmig, 1994, from Radix auricularia (Linnaeus, 1758) for Austria.

Avian schistosomes are of medical and veterinary importance as they are responsible for the annually occurring cercarial dermatitis outbreaks. For Austria, so far, only Trichobilharzia szidati Neuhaus 1952 was confirmed on species level as causative agent of cercarial dermatitis. Here we present the first record of Trichobilharzia franki Müller & Kimmig 1994 in Austria. The species was detected during a survey of digenean trematodes in Upper Austrian water bodies. Furthermore, we provide DNA barcodes of T. franki as well as measurements of several parasite individuals to indicate the intraspecific diversity. We also recommend the usage of an alternative primer pair, since the "standard COI primer pair" previously used for Schistosomatidae amplified an aberrant fragment in the sequence of T. franki. Overall, our study shows how limited our knowledge about occurrence and distribution of avian schistosomes in Austria is and how important it is to acquire such a knowledge to estimate ecological and epidemiological risks in the future.

Pyemotes ventricosus Dermatitis: Comet-Shaped Skin Lesions after Contact with Woodworm-Infested Furniture.

A 23-year-old woman presented to our dermatology clinic for the sudden onset of pruritic lesions on her forearms and legs for the past two days ago. She had been restoring used furniture infested with woodworm. We observed many oval "comet-shaped" erythematous maculopapules with a serpiginous track on the exposed parts of her forearms and legs (Figure 1). Considering the temporal relationship and the contact with woodworm, we were able to diagnose it as Pyemotes ventricosus. We prescribed topical corticosteroids twice daily. By the 8th day, the lesions had cleared.

Necroulcerative dermatitis associated with Myxobolus dermatoulcerans n. sp. (Cnidaria: Myxobolidae) in red-bellied piranha, Pygocentrus nattereri Kner (Characiformes: Serrasalmidae), from Peru.

A group of red-bellied piranha, Pygocentrus nattereri Kner, recently imported from Peru exhibited multifocal, cutaneous ulcerations with exposure of the underlying musculature. Skin scrapes yielded moderate numbers of myxospores morphologically consistent with Myxobolus Bütschli, 1882. Myxospores from these fish were morphologically and molecularly distinct from other myxobolids infecting piranha. Myxospores are pyriform to capsular with a rounded posterior and slightly rounded to tapering anterior aspect in valvular view. Myxospore bodies are 14.3-17.8 (mean 16.1) µm long and 7.6-10.3 (mean 8.9) µm wide. Polar capsules are symmetrical, slender, elongate, and measure 7.4-10.2 (mean 9.2) µm long and 2.1-3.7 (mean 3.0) µm wide. Sequence generated for the 18S rRNA gene had no direct matches to any sequence available on GenBank but demonstrated less than 89% nucleotide similarity to various published and unpublished Myxobolus spp. from Piaractus brachypomus (Cuvier) and Colossoma macropomum (Cuvier). This paper provides the morphological and molecular characterisation of Myxobolus dermatoulcerans n. sp. from red-bellied piranha and describes associated pathological lesions.

Disseminated Neospora caninum infection in a dog with severe colitis.

A 12-y-old spayed female Schipperke dog with a previous diagnosis of inflammatory bowel disease was presented with a 2-mo history of severe colitis. The patient's condition progressed to hepatopathy, pneumonia, and dermatitis following management with prednisolone and dexamethasone sodium phosphate. Colonic biopsies identified severe necrosuppurative colitis with free and intracellular parasitic zoites. Postmortem examination confirmed extensive chronic-active ulcerative colitis, severe acute necrotizing hepatitis and splenitis, interstitial pneumonia, ulcerative dermatitis, myelitis (bone marrow), and mild meningoencephalitis with variable numbers of intracellular and extracellular protozoal zoites. PCR on samples of fresh colon was positive for Neospora caninum. Immunohistochemistry identified N. caninum tachyzoites in sections of colon, and a single tissue cyst in sections of brain. Administration of immunosuppressive drugs may have allowed systemic dissemination of Neospora from the intestinal tract.

Confirmation of the presence of zoonotic Trichobilharzia franki following a human cercarial dermatitis outbreak in recreational water in Slovakia.

Human cercarial dermatitis is a parasitic disease that causes an allergic reaction in the skin (swimmer's itch) as a consequence of contact with cercariae of bird schistosomes present in water, mainly of the genus Trichobilharzia Skrjabin et Zakarow, 1920. The main objective of the study was to confirm the presence of the zoonotic disease agent following reports of human infections in recreational water in Slovakia. We identified two species of freshwater snails at Kosice Lake, Radix auricularia (Linnaeus, 1758) and Physa acuta (Draparnaud, 1805). Trematode infections were observed only in R. auricularia. Of the 62 snails collected, 11 (17.7%) were infected with 5 different species of larval stages of trematodes. The blood fluke Trichobilharzia franki was found in 2 (3.2%) of the examined snails. The present record provides the first evidence that T. franki from the pulmonate snail R. auricularia represents a source of human cercarial dermatitis in recreational water in Slovakia. Our finding complements the easternmost records of both swimmer's itch and the confirmed occurrence of a bird schistosome in a waterbody in Europe. The present work suggests that the health risks associated with trichobilharziasis need to be further studied by detailed monitoring of the occurrence of the major causative agent of human cercarial dermatitis, T. franki.

The peripheral immune response of mice infected with a neuropathogenic schistosome.

Trichobilharzia regenti (Schistosomatidae) percutaneously infects birds and mammals and invades their central nervous system (CNS). Here, we characterized the peripheral immune response of infected mice and showed how it was influenced by the parasite-induced inflammation in the skin and the CNS. As revealed by flow cytometry, T cells expanded in the spleen and the CNS-draining lymph nodes 7-14 days post-infection. Both T-bet+ and GATA-3+ T cells were markedly elevated suggesting a mixed type 1/2 immune response. However, it dropped after 7 dpi most likely being unaffected by the neuroinflammation. Splenocytes from infected mice produced a high amount of IFN-γ and, to a lesser extent, IL-10, IL-4 and IL-17 after in vitro stimulation by cercarial homogenate. Nevertheless, it had only a limited capacity to alter the maturation status of bone marrow-derived dendritic cells (BMDCs), contrary to the recombinant T. regenti cathepsin B2, which also strongly augmented expression of Ccl5, Cxcl10, Il12a, Il33 and Il10 by BMDCs. Taken together, mice infected with T. regenti developed the mixed type 1/2 immune response, which was driven by the early skin inflammation rather than the late neuroinflammation. Parasite peptidases might play an active role in triggering the host immune response.

Oral migration of Dirofilaria repens after creeping dermatitis.

We report an autochthonous case of oral dirofilariasis in a 46-year-old female patient exposed in South-Eastern France. The patient first presented eyelid creeping dermatitis of one-week duration, then a sub-mucosal nodule appeared in the cheek. The entire nodule was removed surgically. Histologically, the nodule appeared as inflammatory tissue in which a worm was seen. The molecular analysis, based on cox1 and 12S sequences, identified Dirofilaria repens. Ivermectin treatment was given prior to diagnosis, while taking into consideration the most common causes of creeping dermatitis, but treatment was ineffective. The oral form of dirofilariasis is uncommon and could lead to diagnostic wandering.

TITLE: Migration orale de Dirofilaria repens après une dermatite rampante. ABSTRACT: Nous rapportons un cas autochtone de dirofilariose buccale chez une patiente de 46 ans exposée dans le sud-est de la France. La patiente a d'abord présenté une dermatite rampante des paupières d'une durée d'une semaine, puis un nodule sous-muqueux est apparu dans la joue. Le nodule entier a été retiré chirurgicalement. Histologiquement, le nodule est apparu comme un tissu inflammatoire dans lequel un ver a été observé. L'analyse moléculaire, basée sur des séquences de cox1 et 12S, a identifié Dirofilaria repens. Le traitement à l'ivermectine a été administré avant le diagnostic tout en tenant compte des causes les plus courantes de la dermatite rampante, mais il était inefficace. La forme orale de la dirofilariose est rare et pourrait conduire à une errance diagnostique.

Diagnosis and treatment of demodicosis in dogs and cats: Clinical consensus guidelines of the World Association for Veterinary Dermatology.

BACKGROUND: Demodicosis is a common disease in small animal veterinary practice worldwide with a variety of diagnostic and therapeutic options. OBJECTIVES: To provide consensus recommendations on the diagnosis, prevention and treatment of demodicosis in dogs and cats. METHODS AND MATERIALS: The authors served as a Guideline Panel (GP) and reviewed the literature available before December 2018. The GP prepared a detailed literature review and made recommendations on selected topics. A draft of the document was presented at the North American Veterinary Dermatology Forum in Maui, HI, USA (May 2018) and at the European Veterinary Dermatology Congress in Dubrovnik, Croatia (September 2018) and was made available via the World Wide Web to the member organizations of the World Association for Veterinary Dermatology for a period of three months. Comments were solicited and responses were incorporated into the final document. CONCLUSIONS: In young dogs with generalized demodicosis, genetic and immunological factors seem to play a role in the pathogenesis and affected dogs should not be bred. In old dogs and cats, underlying immunosuppressive conditions contributing to demodicosis should be explored. Deep skin scrapings are the diagnostic gold standard for demodicosis, but trichograms and tape squeeze preparations may also be useful under certain circumstances. Amitraz, macrocyclic lactones and more recently isoxazolines have all demonstrated good efficacy in the treatment of canine demodicosis. Therapeutic selection should be guided by local drug legislation, drug availability and individual case parameters. Evidence for successful treatment of feline demodicosis is strongest for lime sulfur dips and amitraz baths.

Outbreak of Swimmer's Itch in Denmark.

Swimmer's itch, or cercarial dermatitis, is a waterborne non-communicable skin condition caused by schistosome cercariae released by aquatic snails. Cercarial dermatitis appears worldwide, but may be caused by different trematode species. The itchy maculopapular rash develops on exposed areas of the skin and typically resolves within 1-3 weeks. Shedding of infective larvae from snails is temperature dependent, and high temperatures and sunshine increase the risk of encountering the parasite and becoming infected. The unusually warm spring and summer of 2018 led to an increasing number of reports of the condition in Denmark and established a collaboration between the Department of Dermatology and the Faculty of Health and Medical Sciences, Department of Veterinary and Animal Sciences. This study explored the clinical picture of the disease, and demonstrated the occurrence of infected fresh water snail species in selected Danish water bodies. In conclusion, a risk of swimmer's itch in Denmark was confirmed.