Sarna costrosa: revisión sobre aspectos clínicos de una ectoparasitosis desatendida y de presentación infrecuente / Crusty scabies: review of the clinical aspects of a neglected and infrequent ectoparasitosis

En esta revisión de la literatura se describen aspectos epidemiológicos, fisiopatológicos, clínicos y terapéuticos sobre una presentación atípica y grave de escabiosis, la sarna costrosa o noruega. Esta presentación de escabiosis destaca por afectar principalmente a personas con condiciones de inmunodepresión o sociales que las hacen susceptibles de una alta carga parasitaria, además se asocia a un peor pronóstico y a riesgo de complicaciones. Desde el punto de vista terapéutico, sus estrategias difieren del manejo de la escabiosis clásica.(AU)

This literature review describes epidemiological, pathophysiological, clinical and therapeutic aspects of an atypical and severe presentation of scabies, Norwegian or crusty scabies. This presentation of scabies stands out because it mainly affects people with immunosuppressive or social conditions that make them susceptibleto a high parasite load, it is also associated with a worse prognosis and risk of complications. From a therapeutic point of view, their strategies differ from the management of classic scabies.(AU)

First report of interspecific transmission of sarcoptic mange from Iberian ibex to wild boar.

BACKGROUND: Sarcoptic mange is a globally distributed parasitic disease caused by the burrowing mite Sarcoptes scabiei. This mite has a certain degree of host specificity, although interspecific transmission can occur among phylogenetically related species or through prey-predator mediated exposure. In 2018, a wild boar (Sus scrofa) with lesions compatible with sarcoptic mange was hunted in Ports de Tortosa i Beseit Natural Park (PTB, north-eastern Spain), where an active epizootic outbreak of sarcoptic mange is affecting Iberian ibexes (Capra pyrenaica) since 2014. METHODS: A complete necropsy, skin scrapings and skin digestions with hydroxide potassium were performed to confirm the diagnosis. Routine histopathological analysis, toluidine blue staining and immunohistochemistry were used to characterize the lesions and the inflammatory infiltrate. Finally, 10 specific S. scabiei microsatellites were molecularly genotyped through polymerase chain reactions in mites obtained from the affected wild boar. For phylogenetic comparison, mites obtained from sympatric Iberian ibexes and allopatric wild boars and Iberian ibexes from southern Spain were analysed. RESULTS: Sarcoptes scabiei was visually and molecularly identified in the infested wild boar from PTB, causing skin lesions with dermal inflammatory infiltrate rich in T and B cells, which indicate an adaptive immune response. Three S. scabiei genetic clusters were identified: one included mites from southern Iberian ibexes, another included mites from southern wild boars, and a third one distinctively grouped the wild boar from PTB with the sympatric ibexes. CONCLUSIONS: To the authors' knowledge, this is the first reported case of sarcoptic mange in wild boar in Spain and the first documented case of S. scabiei cross-transmission from a wild ruminant host to a wild boar. The wild boar presented an ordinary scabies type reaction, which is typical of the self-limiting infestations reported in other cases of interspecific transmission.

Development of a rapid scabies immunodiagnostic assay based on transcriptomic analysis of Sarcoptes scabiei var. nyctereutis.

Scabies is a highly contagious skin disease caused by the mite Sarcoptes scabiei that affects many mammals. However, the sensitivity of traditional tests for scabies diagnosis in humans is less than 50%. To simplify the diagnosis of scabies, methods that are simple, sensitive, specific, and cost-effective are required. We developed an immunodiagnostic test based on S. scabiei var. nyctereutis RNA-seq data collected from Japanese raccoon dogs with sarcoptic mange. Three candidate antigens-a highly expressed hypothetical protein "QR98_0091190," another mite allergen known as "SMIPP-Cc," and an abundant "vitellogenin-like protein"-were evaluated by western-blot analysis. A lateral flow immunoassay, using specific antibodies against the vitellogenin-like protein, successfully detected scabies in the skin flakes of S. scabiei-infected raccoon dogs. This assay can potentially diagnose scabies more accurately in wildlife, as well as in humans.

A biological model of scabies infection dynamics and treatment informs mass drug administration strategies to increase the likelihood of elimination.

Infections with Sarcoptes scabiei, or scabies, remain common in many disadvantaged populations. Mass drug administration (MDA) has been used in such settings to achieve a rapid reduction in infection and transmission, with the goal of eliminating the public health burden of scabies. While prevalence has been observed to fall substantially following such an intervention, in some instances resurgence of infection to baseline levels has occurred over several years. To explore the biology underpinning this phenomenon, we have developed a theoretical model of scabies life-cycle and transmission dynamics in a homogeneously mixing population, and simulate the impact of mass drug treatment strategies acting on egg and mite life cycle stages (ovicidal) or mites alone (non-ovicidal). In order to investigate the dynamics of the system, we first define and calculate the optimal interval between treatment doses. We calculate the probability of eradication as a function of the number of optimally-timed successive treatment doses and the number of years over which a program is run. For the non-ovicidal intervention, we first show that at least two optimally-timed doses are required to achieve eradication. We then demonstrate that while more doses over a small number of years provides the highest chance of eradication, a similar outcome can be achieved with fewer doses delivered annually over a longer period of time. For the ovicidal intervention, we find that doses should be delivered as close together as possible. This work provides a platform for further research into optimal treatment strategies which may incorporate heterogeneity of transmission, and the interplay between MDA and enhancement of continuing scabies surveillance and treatment strategies.

Impact of Ivermectin Mass Drug Administration for Lymphatic Filariasis on Scabies in Eight Villages in Kongwa District, Tanzania.

Scabies was recently added to the World Health Organization list of neglected tropical diseases. The ability to treat scabies with oral ivermectin makes a mass drug administration (MDA) campaign a feasible option for scabies control. Ivermectin MDA in communities endemic for lymphatic filariasis (LF) or onchocerciasis may already be having an impact on scabies. We examined the effect of ivermectin MDA for LF on scabies prevalence over 4 years in eight Tanzanian villages. At baseline, 4.4% (95% confidence interval [CI]: 3.7-5.4) of individuals tested positive for scabies, decreasing to 0.84% (95% CI: 0.51-1.4) after one round of ivermectin MDA but increased in Year 3 (2.5% [95% CI: 1.9-3.3]) and Year 4 (2.9% [95% CI: 2.2-3.8]). Most scabies cases were seen in children younger than 15 years. The data suggest that single-dose ivermectin MDA may not be effective in attaining long-term decreases when scabies prevalence is less than 5%.

Sarcoptic mange (Sarcoptes scabiei) in wild canids (Cerdocyon thous) / Sarna sarcóptica (Sarcoptes scabiei) em cachorro-do-mato (Cerdocyon thous)

Crab-eating foxes (Cerdocyon thous) are wild canids found in practically all Brazilian states. They usually live and hunt in pairs, but can be found in small groups, which favors the transmission of diseases such as sarcoptic mange. This study aims to describe the epidemiological, parasitological and pathological findings of two fatal cases of sarcoptic mange in C. thous. Two wild canids were necropsied and cytological examination of skin and crust samples and histologic evaluation of various tissue samples were performed. Gross findings included poor body condition and extensive alopecia with thick skin crusts interspersed by intensely reddened alopecic areas. The cytological examination revealed numerous mites with short gnathosoma and rounded idiosoma that were transversally striated and presented triangular spines on the dorsal surface, terminal anus, and short and thick legs, characteristic of Sarcoptes scabiei. Histologic examination of the skin revealed numerous tunnels into and under the stratum corneum of the epidermis containing high amounts of S. scabiei. The mites were associated with marked acanthosis and hyperkeratosis, and mild superficial dermatitis. The findings reveal that sarcoptic mange is an important disease in wild canids.(AU)

Cachorros-do-mato (Cerdocyon thous) são canídeos selvagens encontrados em praticamente todos os estados brasileiros. Geralmente vivem e caçam em pares, mas podem ser encontrados em pequenos grupos, o que favorece a transmissão de doenças, como a sarna sarcóptica. O presente trabalho tem como objetivo descrever os achados epidemiológicos, parasitológicos e patológicos de dois casos fatais de sarna sarcóptica em cachorros-do-mato. Foram realizados necropsia de dois cachorros do mato, exame citológico de amostras de pele e crostas e exame histológico de amostras dos órgãos e tecidos. Na necropsia foram observados mau estado corporal, extensas áreas de alopecia, crostas cutâneas espessas que se desprendiam e eram intercaladas por áreas alopécicas intensamente eritematosas. No exame citológico foi observada grande quantidade de ácaros com gnatossoma curto e largo, idiossoma globoso, transversalmente estriado e com espinhos triangulares na superfície dorsal, ânus terminal e pernas curtas e grossas, característicos de Sarcoptes scabiei. Ao exame histológico da pele havia muitos túneis no estrato córneo da epiderme e abaixo dele, contendo grande quantidade de S. scabiei. Essas estruturas parasitárias estavam associadas a acantose e hiperqueratose acentuadas e dermatite superficial discreta. Os achados revelam a sarna sarcóptica como uma doença importante em cachorros do mato.(AU)

SARCOPTIC MANGE IN ENDANGERED KIT FOXES (VULPES MACROTIS MUTICA): CASE HISTORIES, DIAGNOSES, AND IMPLICATIONS FOR CONSERVATION.

The San Joaquin kit fox ( Vulpes macrotis mutica) is a federally endangered small carnivore whose distribution is limited to the San Joaquin Valley in central California. Population decline is due to profound habitat loss, and conservation of all remaining populations is critical. A robust urban population occurs in the city of Bakersfield. In spring of 2013, putative cases of mange were reported in this population. Mites from affected animals were confirmed to be Sarcoptes scabiei morphologically and by DNA sequencing. By the end of 2014, 15 cases of kit foxes with mange had been confirmed. As with other species, sarcoptic mange in kit foxes is characterized by intense pruritus and dermatitis, caused by mites burrowing into the epidermal layers, as well as alopecia, hyperkeratosis, and encrustations, secondary bacterial infections, and finally extreme morbidity and death. Of the 15 cases, six foxes were found dead, six were captured but died during attempted rehabilitation, and three were successfully treated. We have no evidence that untreated kit foxes can recover from mange. Sarcoptic mange constitutes a significant threat to the Bakersfield kit fox population and could pose an even greater threat to this imperiled species if it spreads to populations in nearby natural lands.

The threatening but unpredictable Sarcoptes scabiei: first deadly outbreak in the Himalayan lynx, Lynx lynx isabellinus, from Pakistan.

Although neglected, the mite Sarcoptes scabiei is an unpredictable emerging parasite, threatening human and animal health globally. In this paper we report the first fatal outbreak of sarcoptic mange in the endangered Himalayan lynx (Lynx lynx isabellinus) from Pakistan. A 10-year-old male Himalayan lynx was found in a miserable condition with severe crusted lesions in Chitral District, and immediately died. Post-mortem examination determined high S. scabiei density (1309 mites/cm(2) skin). It is most probably a genuine emergence, resulting from a new incidence due to the host-taxon derived or prey-to-predator cross-infestation hypotheses, and less probable to be apparent emergence resulting from increased infection in the Himalayan lynx population. This is an alarming situation for the conservation of this already threatened population, which demands surveillance for early detection and eventually rescue and treatment of the affected Himalayan lynx.

Serie parasitosis en dermatología: escabiosis / Series parasitosis in dermatology: scabies

La escabiosis es una ectoparasitosis pruriginosa producida por el ácaro Sarcoptes scabiei, variedad hominis, específica del ser humano. Si bien su distribución es universal, con frecuencia es subdiagnosticada por asociarla únicamente a hacinamiento y malos hábitos de higiene. Se transmite por contacto directo con una persona afectada o a través de fómites, por lo que es muy común el contagio de los convivientes. Presentamos un caso de escabiosis en una paciente anciana evaluada por prurito generalizado. (AU)

Scabies is a human specific pruritic ectoparasitosis produced by the mite Sarcoptes scabiei var. hominis. Although it has a worldwide distribution, it is often underdiagnosed because it is only associated with overcrowding and poor hygiene. It is transmitted by a direct contact with an affected person or through fomites. The transmission to cohabitants is very common. We present a case of scabies in an elderly patient with generalized pruritus. (AU)

Bullous scabies: a case report and review of the literature.

BACKGROUND: Scabies is a common parasitic infection caused by the mite Sarcoptes Scabiei. About 300 million cases of scabies are reported annually. Scabies usually presents clinically with an erythematous excoriated papulovesicular rash, burrows, nodules and hyperkeratotic lesions in specific body areas. A rare presentation of scabies is the bullous pemphigoid-like bullous scabies. So far, to the best of our knowledge, only 32 cases of bullous scabies have been reported in medical literature, of which only 11 were under 60 years of age at the time of initial presentation. This is the first case of bullous scabies being reported from Pakistan. CASE PRESENTATION: Herein we discuss, with reference to the existing literature, the case of a 23-year-old Punjabi male who presented with a 3 day history of a tense, non-erythematous, non-tender bulla measuring approximately 0.5 cm x 0.8 cm on the right foot near the interdigital cleft. He was diagnosed to have bullous scabies. CONCLUSION: The diagnosis of scabies should be considered in all patients who present with tense bullous lesions accompanied by pruritus and a maculopapular rash. This is particularly relevant if these lesions do not resolve with steroid treatment. In such patients, in order to prevent a misdiagnosis of bullous pemphigoid, scrapings for Sarcoptes Scabiei mites and eggs should be taken.

Prevalence of Sarcoptes scabiei infection in pet dogs in southern China.

Little is known about the prevalence of Sarcoptes scabiei infection in pet dogs in China. In the present study, the prevalence of S. scabiei infection in pet dogs in Guangzhou, southern China, was investigated between January and December, 2009. A total of 3,977 pet dogs admitted to animal hospitals were examined for the presence of S. scabiei using a parasitological approach. The average prevalence of S. scabiei infection in pet dogs is 1.18% (95% confidence interval (CI): 0.85-1.52%). The prevalence of S. scabiei was higher in winter (1.42%; 95% CI: 0.29-2.55%), summer (1.39%; 95% CI: 0.83-1.96%), and autumn (1.1%; 95% CI: 0.53-1.68%) than in spring (0.63%; 95% CI: 0.02-1.25%). Furthermore, the prevalence of S. scabiei was the highest in Pekingese (21.88%; 95% CI: 7.55-36.2%), followed by Papillon (5.26%; 95% CI: 0-11.06%) and Bichon Frise (3.19%; 95% CI: 0-6.75%). The results of the present investigation indicate that S. scabiei infection is prevalent in pet dogs in Guangzhou, China, which provides relevant "baseline" data for conducting control strategies and measures against scabies in this region and elsewhere in China. To our knowledge, this is the first comprehensive report of S. scabiei prevalence in pet dogs in China.

Scabies.

Scabies infestation in humans is a complex interplay between mite, host, and host environment. New techniques for diagnosis, treatment, and eradication are constantly in flux due to varying presentations of scabetic eruptions, a dearth of especially sensitive and specific measures for diagnosis, resistances to pharmacologic therapy, and disparate regional resources. This review will provide an update on the clinical variations, detection methods, and management options.

Intense nocturnal itching should raise suspicion of scabies.

Scabies is caused by infestation with a parasitic mite Sarcoptes scabiei var hominis. The itch and rash appear to be largely the result of a delayed (type IV) allergic reaction to the mite, its eggs and excreta. Scabies is spread by a mite transferring to the skin surface of an unaffected person, usually by skin to skin contact with an infested person, but occasionally via contaminated bed linen, clothes or towels. In crusted scabies, mites are also dispersed within shed scales, enabling the condition to be contracted from contaminated surfaces. Patients with classical scabies usually present with an itchy non-specific rash. Often, the history alone can be 0032-6518 virtually diagnostic. An intense itch, affecting all body regions except the head, typically worse at night, appearing to be out of proportion to the physical evidence, with a close contact also itching, should prompt serious consideration of scabies. The generalised hypersensitivity rash consists of erythematous macules and papules with excoriation. Close inspection will reveal burrows usually up to 1 cm in length. The pathognomic sign of scabies is the presence of burrows. The crusted variant of scabies may not be itchy. It is characterised by areas of dry, scaly, hyperkeratotic and crusted skin, particularly on the extremities. Referral to secondary care should be considered in the following cases: diagnostic doubt; patient under two months of age; lack of response to two ourses of different insecticides; crusted scabies; or history suggests a isk of sexually transmitted infection. Outbreaks of scabies in institutions should be referred to the local health protection services.

Crusted scabies-associated immune reconstitution inflammatory syndrome.

BACKGROUND: Despite the widely accepted association between crusted scabies and human immunodeficiency virus (HIV)-infection, crusted scabies has not been included in the spectrum of infections associated with immune reconstitution inflammatory syndrome in HIV-infected patients initiating antiretroviral therapy. CASE PRESENTATION: We report a case of a 28-year-old Mexican individual with late HIV-infection, who had no apparent skin lesions but soon after initiation of antiretroviral therapy, he developed an aggressive form of crusted scabies with rapid progression of lesions. Severe infestation by Sarcoptes scabiei was confirmed by microscopic examination of the scale and skin biopsy. Due to the atypical presentation of scabies in a patient responding to antiretroviral therapy, preceded by no apparent skin lesions at initiation of antiretroviral therapy, the episode was interpreted for the first time as "unmasking crusted scabies-associated immune reconstitution inflammatory syndrome". CONCLUSION: This case illustrates that when crusted scabies is observed in HIV-infected patients responding to antiretroviral therapy, it might as well be considered as a possible manifestation of immune reconstitution inflammatory syndrome. Patient context should be considered for adequate diagnosis and treatment of conditions exacerbated by antiretroviral therapy-induced immune reconstitution.

Parasite invasion following host reintroduction: a case study of Yellowstone's wolves.

Wildlife reintroductions select or treat individuals for good health with the expectation that these individuals will fare better than infected animals. However, these individuals, new to their environment, may also be particularly susceptible to circulating infections and this may result in high morbidity and mortality, potentially jeopardizing the goals of recovery. Here, using the reintroduction of the grey wolf (Canis lupus) into Yellowstone National Park as a case study, we address the question of how parasites invade a reintroduced population and consider the impact of these invasions on population performance. We find that several viral parasites rapidly invaded the population inside the park, likely via spillover from resident canid species, and we contrast these with the slower invasion of sarcoptic mange, caused by the mite Sarcoptes scabiei. The spatio-temporal patterns of mange invasion were largely consistent with patterns of host connectivity and density, and we demonstrate that the area of highest resource quality, supporting the greatest density of wolves, is also the region that appears most susceptible to repeated disease invasion and parasite-induced declines. The success of wolf reintroduction appears not to have been jeopardized by infectious disease, but now shows signs of regulation or limitation modulated by parasites.