Diversity of Trichobilharzia in New Zealand with a new species and a redescription, and their likely contribution to cercarial dermatitis.

In response to annual outbreaks of human cercarial dermatitis (HCD) in Lake Wanaka, New Zealand, ducks and snails were collected and screened for avian schistosomes. During the survey from 2009 to 2017, four species of Trichobilharzia were recovered. Specimens were examined both morphologically and genetically. Trichobilharzia querquedulae, a species known from four continents, was found in the visceral veins of the duck Spatula rhynchotis but the snail host remains unknown. Cercaria longicauda [i.e. Trichobilharzia longicauda (Macfarlane, 1944) Davis, 2006], considered the major aetiological agent of HCD in Lake Wanaka, was discovered, and redescribed from adults in the visceral veins of the duck Aythya novaeseelandiae and cercariae from the snail Austropeplea tomentosa. Recovered from the nasal mucosa of Ay. novaeseelandiae is a new species of Trichobilharzia that was also found to cycle naturally through Au. tomentosa. Cercariae of a fourth species of Trichobilharzia were found in Au. tomentosa but the species remains unidentified.

Dermoscopy of skin parasitoses, bites and stings: a systematic review of the literature.

Besides classic applications, dermoscopy has gained significant appreciation also for non-tumoral dermatoses (general dermatology). In this field, skin parasitoses (infestations), bites and stings have been reported among the conditions that may benefit most from dermoscopic examination. However, published data on this topic are sparse and often lack a standardized analytical approach. In this systematic review of the literature, we sought to summarize available data on dermoscopy of cutaneous parasitoses, bites and stings, analysing dermoscopic features and used setting (polarization or not/magnification), pathological correlation and level of evidence of published studies as well as trying to align dermoscopic terminology of reported findings following a standardized methodology. A total of 150 publications addressing 29 different dermatoses and reporting 96 different dermoscopic findings were included in the analysis. Most of them displayed a level of evidence of V (113 single case reports and 36 case series), with only one study featuring a level of evidence of IV (case-control study). Additionally, our analysis also displayed poor uniformity in the terminology used in published articles (even for the same dermatosis). Therefore, albeit promising, dermoscopy of cutaneous parasitoses, bites and stings needs future systematized studies for a better characterization.

A report of Bilharziella polonica cercariae in Knowsley Safari, Prescot, United Kingdom, with notes on other trematodes implicated in human cercarial dermatitis.

As part of surveillance of snail-borne trematodiasis in Knowsley Safari (KS), Prescot, United Kingdom, a collection was made in July 2021 of various planorbid (n = 173) and lymnaeid (n = 218) snails. These were taken from 15 purposely selected freshwater habitats. In the laboratory emergent trematode cercariae, often from single snails, were identified by morphology with a sub-set, of those most accessible, later characterized by cytochrome oxidase subunit 1 (cox1) DNA barcoding. Two schistosomatid cercariae were of special note in the context of human cercarial dermatitis (HCD), Bilharziella polonica emergent from Planorbarius corneus and Trichobilharzia spp. emergent from Ampullacaena balthica. The former schistosomatid was last reported in the United Kingdom over 50 years ago. From cox1 analyses, the latter likely consisted of two taxa, Trichobilharzia anseri, a first report in the United Kingdom, and a hitherto unnamed genetic lineage having some affiliation with Trichobilharzia longicauda. The chronobiology of emergent cercariae from P. corneus was assessed, with the vertical swimming rate of B. polonica measured. We provide a brief risk appraisal of HCD for public activities typically undertaken within KS educational and recreational programmes.

Chronic demodicosis in patients with immune dysregulation: An unexpected infectious manifestation of Signal transducer and activator of transcription (STAT)1 gain-of-function.

Signal transducer and activator of transcription (STAT)1 heterozygous gain-of-function (GOF) mutations are known to induce immune dysregulation and chronic mucocutaneous candidiasis (CMCC). Previous reports suggest an association between demodicosis and STAT1 GOF. However, immune characterization of these patients is lacking. Here, we present a retrospective analysis of patients with immune dysregulation and STAT1 GOF who presented with facial and ocular demodicosis. In-depth immune phenotyping and functional studies were used to characterize the patients. We identified five patients (three males) from two non-consanguineous Jewish families. The mean age at presentation was 11.11 (range = 0.58-24) years. Clinical presentation included CMCC, chronic demodicosis and immune dysregulation in all patients. Whole-exome and Sanger sequencing revealed a novel heterozygous c.1386C>A; p.S462R STAT1 GOF mutation in four of the five patients. Immunophenotyping demonstrated increased phosphorylated signal transducer and activator of transcription in response to interferon-α stimuli in all patients. The patients also exhibited decreased T cell proliferation capacity and low counts of interleukin-17-producing T cells, as well as low forkhead box protein 3+ regulatory T cells. Specific antibody deficiency was noted in one patient. Treatment for demodicosis included topical ivermectin and metronidazole. Demodicosis may indicate an underlying primary immune deficiency and can be found in patients with STAT1 GOF. Thus, the management of patients with chronic demodicosis should include an immunogenetic evaluation.

[Parasitic dermatoses from abroad]. / Parasitäre Reisedermatosen.

Increased migration, the omnipresent desire to travel, climate change and a globally more mobile population enhance the risk of spreading infectious, tropical pathogens across international borders. In addition to diarrhea and fever, skin diseases present one of the most common reasons for a medical consultation upon return among travelers. These diseases are often caused by parasites. Detailed data on infectious travel diseases is scarce. However, demographic, endemic and travel-related information represent the basic requirements for physicians to choose appropriate diagnostics and adequate treatment for affected patients. This article gives an overview of common parasitic travel dermatoses, their specific diagnostic workup, treatment and preventive measures.

Parasitic skin infections: neglected diseases or just challenging for diagnosis?

PURPOSE OF REVIEW: The aim of the article is to review the most recent evidence concerning parasitic skin infections. RECENT FINDINGS: Parasitic skin infections are increasingly reported worldwide. Special at-risk categories are migrants, returning travelers, and immunocompromised individuals, who are at higher risk to present disseminated disease. The number of reported cases is growing even outside the endemic areas as a consequence of international travels, migration flows, increasing immunocompromised population, climate change, and natural disasters. SUMMARY: Skin parasitoses are neglected infections. Funding assigned to prevent and treat them is limited, even if they affect millions of persons worldwide. Diagnosis could be a challenge for clinicians of high-income countries who are facing an increasing number of such infections related to great epidemiological events.

Direct onshore wind predicts daily swimmer's itch (avian schistosome) incidence at a Michigan beach.

Swimmer's itch (SI) is a painful rash caused by skin penetration by free-swimming infectious cercariae of avian schistosomes, snail-borne helminth parasites related to the causative agents of human schistosomiasis. The goal of this study was to determine if commonly collected environmental data could be used to predict daily fluctuations in SI incidence at an inland beach in northwestern Michigan. Lifeguards collected daily data over four summers, including the number of self-reported SI cases, total swimmers, water temperature, wind speed and wind direction. Mixed-effects binomial regression revealed that wind direction, wind speed and time of day were the best predictors of daily SI risk. Swimmers entering the water in the morning or on days with direct onshore wind perpendicular to the shoreline had the greatest SI risk. However, there was a negative effect of wind speed after accounting for direction, where SI risk was greatest on days with a gentle breeze originating directly offshore. These results suggest that at this beach, direct onshore winds generate a surface-water current that causes SI cercariae to aggregate in the shallow waters used by swimmers. Data are needed from additional sites to confirm whether the onshore wind is a generally important driver of SI incidence.

A case of human Dirofilaria repens infection, causing an asymptomatic subcutaneous nodule.

We present a case of subcutaneous dirofilariasis, a vector-borne zoonotic disease, in a young woman from Austria. The diagnosis was confirmed by ultrasound and histology of the excised subcutaneous nodule. The parasite species was identified as Dirofilaria repens by polymerase chain reaction. We expect to see more cases of human dirofilariasis also due to climate change and associated increase of the spectrum of suitable mosquito vectors.

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.

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.

Mefenoxam, Itraconazole, and Terbinafine Combination Therapy for Management of Pythiosis in Dogs (Six Cases).

Pythium insidiosum is an oomycete that encysts in the skin or gastrointestinal tract, leading to pythiosis. Pythiosis is reported in tropical and subtropical climates, affecting dogs and rarely cats. Surgical resection is the treatment of choice; however, cases present late in the disease and lesions are often nonresectable. Medical management is typically unsuccessful, with uncommon exceptions; however, mefenoxam, an agricultural fungicide, has in vitro efficacy against P insidiosum. We describe the use of mefenoxam, itraconazole, and terbinafine (MIT) in five dogs with gastrointestinal pythiosis and one dog with cutaneous pythiosis. Two of the gastrointestinal cases had disease extending to surgical margins and received MIT: resolution of clinical signs and seronegativity occurred after 189-193 days. Another case underwent surgical resection and MIT. The dog improved but subsequently developed a rectal mass, which responded to addition of prednisone and immunotherapy. Two cases were treated with MIT alone, and response varied. Efficacy of MIT in cutaneous pythiosis could not be determined. MIT may result in improved survival and seronegativity in dogs with incompletely resected gastrointestinal pythiosis. Mefenoxam is EPA registered, and extralabel use under the Animal Medicinal Drug Use Clarification Act does not apply. Additional research is recommended before use.

Exploring Tropical Infections: A Focus on Cutaneous Larva Migrans.

GENERAL PURPOSE: To provide information about infection with cutaneous larva migrans (CLM). TARGET AUDIENCE: This continuing education activity is intended for physicians, physician assistants, NPs, and nurses with an interest in skin and wound care. LEARNING OBJECTIVES/OUTCOMES: After participating in this educational activity, the participant will:1. Distinguish the clinical features, diagnosis, and management of CLM.2. Explain the epidemiology of CLM. ABSTRACT: Cutaneous larva migrans is a hookworm infection and one of the most common skin diseases of tourists in tropical countries. Most commonly, the infection is transmitted by contact with feces of dogs and cats containing hookworm eggs. This case-based review explores the epidemiology, diagnosis, clinical features, and management of cutaneous larva migrans infection.

Cutaneous larva migrans is a hookworm infection and one of the most common skin diseases of tourists in tropical countries. Most commonly, the infection is transmitted by contact with feces of dogs and cats containing hookworm eggs. This case-based review explores the epidemiology, diagnosis, clinical features, and management of cutaneous larva migrans infection.

Reflectance confocal microscopy for the diagnosis of skin infections and infestations.

Reflectance confocal microscopy (RCM) is a noninvasive real-time imaging technique that has been widely used for the diagnosis of skin cancer. More recently, it has been reported as a useful tool for the diagnosis and management of several inflammatory and infectious skin disorders. This article provides an overview of the current available applications of RCM use in cutaneous infections and infestations. PubMed was used to search the following terms in various combinations: reflectance confocal microscopy, skin, hair, nail, infection, parasitosis, mycosis, virus, bacteria. All papers were accordingly reviewed. In most cutaneous infections or infestations, the main alterations are found in the epidermis and upper dermis, where the accuracy of confocal microscopy is nearly similar to that of histopathology. The high resolution of this technique allows the visualization of most skin parasites, fungi, and a few bacteria. Although viruses cannot be identified because of their small size, viral cytopathic effects can be observed on keratinocytes. In addition, RCM can be used to monitor the response to treatment, thereby reducing unnecessary treatments.

Mucosal Leishmaniasis in Travelers with Leishmania braziliensis Complex Returning to Israel.

Mucosal leishmaniasis (ML) is a complication of New World cutaneous leishmaniasis (CL) caused mainly by Leishmania (Viannia) braziliensis. This retrospective study investigated all cases of ML caused by L. (V.) braziliensis in a tertiary medical center in Israel, evaluating the risk factors, clinical presentations, diagnosis, treatment, and outcome of mucosal involvement in ML caused by L. (V.) braziliensis in travelers returning to Israel. During 1993-2015, a total of 145 New World CL cases were seen in travelers returning from Bolivia; among them, 17 (11.7%) developed ML. Nasopharyngeal symptoms developed 0-3 years (median 8 months) after exposure. The only significant risk factor for developing ML was the absence of previous systemic treatment. Among untreated patients, 41% developed ML, compared with only 3% of treated patients (p = 0.005). Systemic treatment for CL seems to be a protective factor against developing ML.

Quantitative proteomic profiling of immune responses to Ichthyophthirius multifiliis in common carp skin mucus.

Ichthyophthirius multifiliis, a ciliated protozoan parasite, causes ichthyophthiriasis and leads to considerable economic losses to the aquaculture industry. Understanding the fish immune response and host-parasite interactions could support developing novel strategies for better disease management and control. Fish skin mucus is the first line of defence against infections through the epidermis. Yet, the common carp, Cyprinus carpio, protein-based defence strategies against infection with I. multifiliis at this barrier remain elusive. The skin mucus proteome of common carp was investigated at 1 day and 9 days post-exposure with I. multifiliis. Using nano-LC ESI MS/MS and statistical analysis, the abundance of 19 immune related and signal transduction proteins was found to be differentially regulated in skin mucus of common carp in response to I. multifiliis. The analysis revealed increased abundance values of epithelial chloride channel protein, galactose-specific lectin nattection, high choriolytic enzyme 1 (nephrosin), lysozyme C, granulin and protein-glutamine gamma-glutamyltransferase 2 in I. multifiliis-exposed carp skin mucus. Multiple lectins and a diverse array of distinct serpins with protease inhibitor activity were identified likely implicated in lectin pathway activation and regulation of proteolysis, indicating that these proteins contribute to the carp innate immune system and the protective properties of skin mucus. The results obtained from this proteomic analysis enables a better understanding of fish host response to parasitic infection and gives insights into the key role skin mucus plays in protecting fish against deleterious effects of I. multifiliis.

Cutaneous myiasis in a traveler returning from Argentina.

Myiasis is a common travel-associated dermatosis. We describe a 52-year-old Italian man who acquired Dermatobia hominis when bitten by a mosquito during a visit to Argentina. He had a painful nodular lesion on the left cheek that had been present for about 3 weeks. The complete removal of the larva is the goal of medical treatment. Prescription of antibiotics to avoid secondary infections is not recommended. For psychological reasons and due to the failure of previous therapies, the lesion was excised. Travelers to endemic areas should be informed of preventive measures to reduce mosquito bites and transmission of the infestation.

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.

Cutaneous schistosomiasis and leishmaniasis coinfection: a case report.

BACKGROUND: The polymorphic clinical presentations of schistosomiasis and leishmaniasis allow their inclusion in the differential diagnoses of several conditions. Although an overlap in distribution of these diseases has been reported in endemic areas, coinfection with cutaneous schistosomiasis and cutaneous leishmaniasis in the same patient is rare. OBJECTIVES: We report an unusual case of concomitant cutaneous schistosomiasis and cutaneous leishmaniasis. Actions for the management and diagnosis were proposed. METHODS: A patient presented with cutaneous lesions on the abdomen and left elbow. The presence of degenerated ova of Schistosoma mansoni in the skin biopsy led to perform a complementary investigation with immunohistochemical techniques, rectal biopsy and abdominal ultrasonography. After the left elbow lesions had failed to improve after several weeks of standard treatment, a new biopsy was performed and led to diagnosis of another infection. RESULTS: The patient lived in an endemic area for two infectious diseases (schistosomiasis and leishmaniasis). Biopsies revealed chronic granulomatous dermatitis. Degenerated S. mansoni eggs were found in the abdominal lesion and in a rectal biopsy specimen. Ultrasonography revealed hepatic involvement. Despite combination treatment with oxamniquine and praziquantel, a cutaneous lesion persisted on the left elbow; a new biopsy revealed amastigote forms of Leishmania. The patient was successfully treated with intramuscular and intralesional meglumine antimoniate. CONCLUSIONS: The presence of a similar granulomatous infiltrate in lesions caused by the two different infectious agents led to a delay in the diagnosis of cutaneous leishmaniasis. This report serves as a warning of the unusual possibility of cutaneous schistosomiasis and leishmaniasis coinfection in an endemic area.

Evaluation of targeted copper sulfate (CuSO4) application for controlling swimmer's itch at a freshwater recreation site in Michigan.

Swimmer's itch has historically been controlled by applying copper sulfate (CuSO4) to lakes as a way to eliminate snails that serve as the intermediate hosts for swimmer's itch-causing parasites. CuSO4 is still sometimes applied specifically to areas of lakes where swimmer's itch severity is high. It is unclear whether targeted application of chemical molluscicides like CuSO4 is effective for controlling swimmer's itch. Previous research has found that the larval stage of the parasites responsible for swimmer's itch are released from infected snails and are concentrated by onshore and alongshore winds, and thus, may not be affected by such focused applications. In this study, we evaluated the impact of targeted CuSO4 application to a specific recreational swimming area in a lake in Michigan. We measured the effect on snail populations, as well as on the presence/abundance of swimmer's itch-causing parasites using qPCR. Ultimately, while CuSO4 was confirmed to significantly reduce populations of snails within the treatment area, it was found to have no significant impact on swimmer's itch-causing parasites in the water, likely due to the free-swimming larval stages (cercariae) moving into the treatment area from surrounding regions.

Parasitic Infections of the Skin and Subcutaneous Tissues.

A variety of arthropods, protozoa, and helminths infect the skin and subcutaneous tissues and may be identified by anatomic pathologists in standard cytology and histology preparations. The specific organisms seen vary greatly with the patient's exposure history, including travel to or residence in endemic countries. Arthropods are the most commonly encountered parasites in the skin and subcutaneous tissues and include Sarcoptes scabei, Demodex species, Tunga penetrans, and myiasis-causing fly larvae. Protozoal parasites such as Leishmania may also be common in some settings. Helminths are less often seen, and include round worms (eg, Dirofilaria spp.), tapeworms (eg, Taenia solium, Spirometra spp.), and flukes (eg, Schistosoma spp.). This review covers the epidemiologic and histopathologic features of common parasitic infections of the skin and subcutaneous tissues.