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.

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.

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.

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.

A Case of Cutaneous Myiasis Caused by Cordylobia anthropophaga Larvae in a Korean Traveler Returning from Central Africa.

The cutaneous myiasis has been rarely reported in the Republic of Korea. We intended to describe here a case of furuncular cutaneous myiasis caused by Cordylobia anthropophaga larvae in a Korean traveler returned from Central Africa. A patient, 55-year-old man, had traveled to Equatorial Guinea, in Central Africa for a month and just returned to Korea. Physical examinations showed 2 tender erythematous nodules with small central ulceration on the left buttock and thigh. During skin biopsy, 2 larvae came out from the lesion. C. anthropophaga was identified by paired mouth hooks (toothed, spade-like, oral hooklets) and 2 posterior spiracles, which lack a distinct chitinous rim. Although rarely described in Korea until now, cutaneous myiasis may be encountered more frequently with increasing international travel and exchange workers to tropical areas.

Demodex canis regulates cholinergic system mediated immunosuppressive pathways in canine demodicosis.

Demodex canis infestation in dogs remains one of the main challenges in veterinary dermatology. The exact pathogenesis of canine demodicosis is unknown but an aberration in immune status is considered very significant. No studies have underpinned the nexus between induction of demodicosis and neural immunosuppressive pathways so far. We have evaluated the involvement of cholinergic pathways in association with cytokines regulation as an insight into the immuno-pathogenesis of canine demodicosis in the present study. Remarkable elevations in circulatory immunosuppressive cytokine interleukin-10 and cholinesterase activity were observed in dogs with demodicosis. Simultaneously, remarkable reduction in circulatory pro-inflammatory cytokine tumour necrosis factor-alpha level was observed in dogs with demodicosis. Findings of the present study evidently suggest that Demodex mites might be affecting the cholinergic pathways to induce immunosuppression in their host and then proliferate incessantly in skin microenvironment to cause demodicosis.

Subcutaneous dirofilariasis: a masquerade of a palisaded granulomatous dermatitis.

Dirofilaria species are roundworms responsible for "heartworm" in canines. On occasion, humans are an accidental host, resulting in pulmonary (Dirofilaria immitis) or extrapulmonary (Dirofilaria repens) manifestations. Of the extrapulmonary sites of involvement, subcutaneous involvement is particularly common. We report a case of a 49-year-old female who presented with an erythematous nodule on her shin, which closely resembled necrobiosis lipoidica on histopathologic examination. On closer examination, there were foci of necrosis that harbored segments of the nematode, diagnostic of dirofiliarisis. We present this case to highlight the histopathologic similarities and differences between palisaded necrobiotic conditions and this potentially underrecognized entity.

Parasitic outbreak of the copepod Balaenophilus manatorum in neonate loggerhead sea turtles (Caretta caretta) from a head-starting program.

BACKGROUND: Diseases associated to external parasitosis are scarcely reported in sea turtles. During the last decades several organism have been documented as a part of normal epibiont community connected to sea turtles. The copepod Balaenophilus manatorum has been cited as a part of epibiont fauna with some concern about its parasitic capacity. This study serves three purposes, i.e. (i) it sheds light on the type of life style that B. manatorum has developed with its hosts, particularly turtles; (ii) it makes a cautionary note of the potential health risks associated with B. manatorum in sea turtles under captivity conditions and in the wild, and (iii) it provides data on effective treatments against B. manatorum. RESULTS: We report for the first time a massive infestation of the copepod B. manatorum and subsequent acute mortality in a group of loggerhead sea turtle hatchlings. Four-month-old turtles from a head-starting program started exhibiting excitatory and fin rubbing behavior preceding an acute onset of lethargy, skin ulceration and death in some animals. All the individuals (n = 57) were affected by severe copepod load and presented different degrees of external macroscopic skin lesions. The ventral area of front flippers, axillar and pericloacal skin were mostly affected, and were the main parasite distribution regions. Copepods were also detected on plastron and carapace sutures. The gut contents of B. manatorum reacted positively for cytokeratin, indicating consumption of turtle skin. Severe ulcerative necrotic dermatitis and large amount of bacteria presence were the major histopathological findings. CONCLUSIONS: Individual fresh water immersion for 10 min and lufenuron administration (0.1 ppm) to the water system every 2 weeks proved effective for removing turtle parasites and to control re-infestation, respectively. The results from our study clearly indicated that B. manatorum individuals consume turtle skin. The pathological effects of this agent and the potential implications in sea turtle conservation and management are discussed.

Skin parasitism by Paratrichosoma recurvum in wild American crocodiles and its relation to environmental and biological factors.

Paratrichosma spp. are capillarid worms that parasitize the abdominal skin of crocodiles. They are likely not a threat to crocodiles' health, but they affect the skins' commercial value. No successful treatment exists against this parasite, and present knowledge of its life cycle is limited. Herein we report new information on Paratrichosoma recurvum occurrence in wild American crocodiles Crocodylus acutus from Mexican Caribbean islands and its relation to environmental (water salinity, temperature, climatic events) and biological (body condition) factors. The percentage of parasitized crocodiles (30.3%) is among the highest recorded in wild crocodilian populations. Small (<40.8 cm total length [TL]) and large (>270 cm TL) crocodiles are less parasitized, probably due to the characteristics of their skin or of the parasite life cycle. Two individuals appeared to have eliminated worms naturally between their capture and recapture. The thorax-abdomen is the most parasitized area of the body of crocodiles. The risk of infection is not associated with the sex of the crocodile, but there was a difference in the proportion of parasitized crocodiles between sites, which could be related to different environmental conditions. The body condition of a crocodile does not seem to be affected by the parasite. Climatic events and water temperature show no effect on the parasitism of crocodiles, but salinity could have an effect. The infection of crocodiles by P. recurvum could depend more on an individual's behavior than on environmental conditions.

Cercopithifilaria sp. II in Vulpes vulpes: new host affiliation for an enigmatic canine filarioid.

Cercopithifilaria bainae and Cercopithifilaria grassii (Spirurida, Onchocercidae) are filarioids inhabiting the skin of dogs worldwide. The microfilariae of a third species namely, Cercopithifilaria sp. II sensu Otranto et al. 2013, have been morphologically and molecularly characterized but scientific knowledge of this parasite is minimal. The first case of infection of a red fox (Vulpes vulpes) with the filarioid Cercopithifilaria sp. II is herein described in Castro Marim, Portugal. Microfilariae from skin sediment of the fox's ear were morphological characterized, and the identification was confirmed molecularly in samples from skin sediment, skin samples, and from Rhipicephalus sanguineus group ticks collected from the animal (99% homology with Cercopithifilaria sp. II). Studies should evaluate if red foxes might play a role in the maintenance and distribution of Cercopithifilaria sp. II infection in dog populations.

Clinical Manifestation of a Patient With Forehead Sparganosis.

Human sparganosis is a parasite infection caused by the larva of a tapeworm of the genus Spirometra. Ocular, central nervous system, auricular, pulmonary, intraosseous, intraperitoneal, and subcutaneous manifestations of this infection in the neck or inguinal region have been described.The authors report the rare occurrence of cutaneous forehead sparganosis of a 19-year-old male who presented with a soft subcutaneous mass in the forehead, along with a related literature review.

Avian schistosomes and outbreaks of cercarial dermatitis.

Cercarial dermatitis (swimmer's itch) is a condition caused by infective larvae (cercariae) of a species-rich group of mammalian and avian schistosomes. Over the last decade, it has been reported in areas that previously had few or no cases of dermatitis and is thus considered an emerging disease. It is obvious that avian schistosomes are responsible for the majority of reported dermatitis outbreaks around the world, and thus they are the primary focus of this review. Although they infect humans, they do not mature and usually die in the skin. Experimental infections of avian schistosomes in mice show that in previously exposed hosts, there is a strong skin immune reaction that kills the schistosome. However, penetration of larvae into naive mice can result in temporary migration from the skin. This is of particular interest because the worms are able to migrate to different organs, for example, the lungs in the case of visceral schistosomes and the central nervous system in the case of nasal schistosomes. The risk of such migration and accompanying disorders needs to be clarified for humans and animals of interest (e.g., dogs). Herein we compiled the most comprehensive review of the diversity, immunology, and epidemiology of avian schistosomes causing cercarial dermatitis.

Recognizing common parasitic infestations.

Parasitic infestations commonly are seen in patients in primary care, urgent care, and EDs. These infestations are a common cause of pruritus and may lead to secondary infestations. This article reviews the signs and symptoms of pinworms, lice, bedbug, and scabies infestations, as well as diagnosis and appropriate treatment.

Tick Bite Alopecia: A Report and Review.

Tick bites can cause a number of local inflammatory reactions, which are often difficult to differentiate from those induced by other arthropod bites or stings. These include erythematous nodular or pustular lesions, erosive plaques, annular lesions of erythema chronicum migrans, and both scarring and nonscarring inflammatory alopecia. We report a case of nonscarring alopecia in a 21-year-old male who reported a recent history of tick bite to the scalp. The biopsy demonstrated a dense pseudolymphomatous inflammatory infiltrate with numerous eosinophils associated with hair follicle miniaturization and an elevated catagen-telogen count. Signs of external rubbing, including lichen simplex chronicus and the "hamburger sign", were also visualized and are indicative of the associated pruritus. To the authors' knowledge, this is the fifth report of nonscarring tick bite alopecia in the literature and the first in an adult patient. This text will review the classic clinical presentation, histologic findings, and proposed mechanism of tick bite alopecia.

Reflectance confocal microscopy for cutaneous infections and infestations.

Reflectance confocal microscopy (RCM) is a high-resolution emerging imaging technique that allows non-invasive diagnosis of several cutaneous disorders. A systematic review of the literature on the use of RCM for the study of infections and infestations has been performed to evaluate the current use of this technique and its possible future applications in this field. RCM is particularly suitable for the identification of Sarcoptes scabies, Demodex folliculorum, Ixodes, Dermatophytes and Candida species in the clinical practice and for the follow-up after treatment. The cytopathic effect of herpes simplex virus, varicella zoster virus and molluscipoxvirus is also detectable by this imaging technique even in a pre-vesicular stage. In addition, thanks to its non-invasiveness, RCM allows pathophysiological studies.

External injuries of Morelet's crocodile Crocodylus moreletii in Campeche, Mexico.

Analysis of external injuries in captive and free-ranging Morelet's crocodiles Crocodylus moreletii was performed in the northern wetlands of Campeche, Mexico. From March to September of 2007, a total of 52 free-ranging and 51 captive Morelet's crocodiles were studied. Captive crocodiles presented significantly more injuries. Sixteen free-ranging crocodiles presented some type of lesion, mostly superficial abrasions. Nineteen captive crocodiles presented lesions, mostly incisions from agonistic interactions. Overall, the injuries with highest prevalence were the incisions. The tail was the most frequently injured body region. Injuries were more common in adults than in other size classes. Conversely, the presence of lesions caused by the parasite Paratrichosoma spp. was greater in crocodiles captured in the coastal channels (mangrove habitat). The information presented here is important to understand some of the effects of individual interactions and to foresee and manage the consequences of conservation and management activities of crocodile populations.

The real threat of swimmers' itch in anthropogenic recreational water body of the Polish Lowland.

After numerous reports the local press about the "stinging water" in created on the Dzierzecinka River-Water Valley reservoir and recognizing in bathers the symptoms of swimmers' itch, environmental study on the presence of bird schistosome larvae in snail hosts was conducted. Snails belonging to Lymnaeidae and Planorbidae were collected at two sites: (i) part of anthropogenic reservoir (192 individuals) and (ii) the river part (37 individuals). Higher prevalence of Digenea was observed in snail populations living in Water Valley (29.8 %) compared to Dzierzecinka River (21.3 %). The larvae of bird schistosomes were recorded in both localities in 1.8 % of collected snails. The prevalence of bird schistosomes reached 2.9 % in Planorbarius corneus, 2.8 % in Radix auricularia, and 5.9 % in Radix balthica/labiata. Laboratory tests have shown that at 19 °C the number of bird schistosome cercariae released from snail hosts significantly exceeded the number of cercariae of other identified Digenea species. It is worth underlining that despite the low prevalence of bird schistosomes, the high number of released cercariae was sufficient to create a real threat of swimmers' itch in bathers. As indicated by the example presented, anthropogenic reservoirs create excellent conditions for Digenea species including bird schistosomes. In view of the real risk of people using the waters, tests on presence of the parasites in snail hosts should be included to the standard procedure of security control in bathing places.