Gotowa bibliografia na temat „Sarcoptic mange”

Sarcoptes scabiei is a parasitic astigmatid mite, which causes scabies in people and sarcoptic mange in mammals. Importantly, it is an emerging disease in wildlife throughout the world. The mite originates from a human ancestor and is thought to have spread to domestic and then free-living animals. Based on the recent emergence of sarcoptic mange in Australian wildlife and Aboriginal communities, it is thought that Sarcoptes scabiei was probably introduced to Australia by the Europeans and their animals. The mitochondrial genetic similarity of mites from Australian wildlife and domestic animals supports this. In Australian wildlife, sarcoptic mange has been reported in the common wombat Vombatus ursinus, southern hairy-nosed wombat Lasiorhinus latifrons, koala Phascolarctos cinereus, common ringtail possum Pseudocheirus peregrinus and in 2003 in the agile wallaby Macropus agilis. Compared with other native species, sarcoptic mange has by far its greatest impact on wombats, particularly common wombats, and is capable of causing high morbidity and mortality rates.

Five free-living common wombats were captured, implanted with radio-transmitters, experimentally infected with 4000, 6000 or 8000 Sarcoptes scabiei var. wombati, then released and later recaptured for assessment of severity of infection, pathology and effect of sarcoptic mange on their behaviour. At the end of the study wombats were treated with ivermectin and amitraz to eradicate infection. Three wombats infected with 6000–8000 mites on their lateral surfaces developed mild sarcoptic mange within 14 weeks of infection. Two wombats infected with 4000 and 8000 mites, respectively, on lateral surfaces developed moderate sarcoptic mange within 14 weeks of infection. Free-living common wombats that were experimentally infected with S. scabiei travelled significantly further at night than wombats without mange; however, they used areas of similar size. They changed burrows for diurnal shelter as frequently as wombats without sarcoptic mange. They investigated and entered burrows during their nocturnal activities. There was no evidence of spread of infection from the five experimentally infected wombats to other wombats within the population by 18 weeks after introduction of S. scabiei.

Sarcoptic mange caused by the mite Sarcoptes scabiei is a worldwide-distributed skin infestation with a wide range of hosts, among them several species within the Felidae family. Sarcoptes scabiei was diagnosed in a dead adult female European wildcat (Felis silvestris silvestris) from Spain, based on histological evaluation of skin biopsies and identification of the arthropod from skin scrapings and molecular methods. This is the first description of Sarcoptes scabiei in a European wildcat. Due to its critical demography in the southernmost population of the Iberian Peninsula, the impacts of infectious diseases, including sarcoptic mange, as a new potential threat should be considered during disease surveillance programs of the species’ populations.

ABSTRACT: 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.

La sarna sarcóptica es una enfermedad parasitaria causada por el ácaro Sarcoptes scabiei. Afecta a mamíferos de todo el mundo, incluyendo al ser humano. En la fauna salvaje se considera una enfermedad emergente, pudiendo causar graves consecuencias poblacionales. La cabra montés (Capra pyrenaica) es un ungulado de montaña endémico de la Península Ibérica. Desde finales de los años 80, las poblaciones de cabra montés del sur y del este peninsular se han visto afectadas por esta parasitosis, con mortalidades variables que han llegado a superar el 90%. La mayoría de los estudios sobre la sarna en la cabra montés se han centrado en la epidemiología y los efectos poblacionales, por lo que no se conoce totalmente la fisiopatología y la patogenia de esta enfermedad en esta especie. En los dos primeros estudios de esta tesis, se analizaron las proteínas de fase aguda (PFA) (Estudio I) y se validó una prueba para la detección de inmunoglobulinas G (IgG) frente S. scabiei (Estudio II) en cabras monteses en libertad, tanto sanas como afectadas por sarna sarcóptica. En el Estudio I, se observó el aumento de las concentraciones de la proteína amiloide sérica tipo A y de la alfa-1 glicoproteína ácida, aunque en menor medida, en función de la extensión de las lesiones causadas por la sarna sarcóptica. Por el contrario, la concentración de haptoglobina no varió entre las cabras monteses sanas y las infestadas. Debido a la falta de un método diagnóstico de laboratorio efectivo, en el Estudio II se evaluaron tres ensayos por inmunoabsorción ligada a enzimas (ELISAs) para detectar IgG frente a S. scabiei en cabra montés, validando uno de los tres ELISAs que mostró una elevada especificidad y sensibilidad, al emplear el sistema de avidina-biotina. Los Estudios III y IV se llevaron a cabo con cabras monteses que presentaban diferentes alelos del gen DRB1 del complejo mayor de histocompatibilidad (MHC) clase II, infestadas experimentalmente con S. scabiei. Aunque todas las cabras infestadas desarrollaron lesiones compatibles con sarna sarcóptica, la evolución clínica varió desde lesiones extensas que afectaron la mayor parte de la superficie corporal hasta lesiones leves y recuperación clínica de la enfermedad (Estudio III). Sin embargo, estas diferencias clínicas no parecieron estar relacionadas con diferencias en el MHC. En las cabras monteses que desarrollaron cuadros clínicos graves de sarna se observó anemia, posiblemente relacionada con la inflamación causada por el ácaro, así como neutrofilia y linfopenia, probablemente debidas a las infecciones secundarias facilitadas por la sarna sarcóptica. La concentración de IgG también aumentó en función de la gravedad de las lesiones. Finalmente, en el Estudio IV se estudió la respuesta genómica de las cabras monteses frente a la infestación experimental con S. scabiei. En las cabras monteses con cuadros clínicos graves se observó un aumento de la expresión génica de vías relacionadas con la inmunidad y la inflamación, reflejo de la respuesta inmune generalizada, exacerbada e ineficaz inducida por el ácaro y de la respuesta frente las infecciones secundarias. Asimismo, las cabras monteses que se recuperaron mostraron un aumento de la expresión de genes relacionados con la presentación de antígeno y de activación de linfocitos T en la piel. Como resumen, la sarna sarcóptica produce cambios tanto sistémicos como locales, causando un aumento de PFA y anticuerpos, así como alteraciones hematológicas y en la expresión génica local y sistémica. Aunque las causas de las diferencias encontradas en la evolución clínica no han podido ser completamente dilucidadas, la inmunidad celular local cutánea puede ser clave en el control de la infestación. La detección de IgG mediante ELISA puede ser útil como método diagnóstico efectivo de la sarna sarcóptica en cabra montés, mientras que las PFA son un indicador pronóstico.
Sarcoptic mange is a parasitic skin disease caused by the burrowing mite Sarcoptes scabiei. It affects mammals worldwide, including humans. Sarcoptic mange in wildlife is considered an emerging disease, and can cause severe population declines. Iberian ibex (Capra pyrenaica) is a medium-sized mountain ungulate endemic to the Iberian Peninsula. Since the end of the ‘80s, the Iberian Ibex populations of Southern and Eastern Spain have been affected by mange, suffering variables mortalities reported to reach up to 90%. Most of the studies on sarcoptic mange in Iberian ibex have focused on the epidemiology and the population consequences of the diseases, thus existing a lack of knowledge about the pathophysiology and pathogenesis of this disease in this species. The two first studies of this thesis analysed the acute phase proteins (APP) (Study I) and validated a test for the detection of immunoglobulins G (IgG) against S. scabiei (Study II) in free-ranging Iberian ibexes, both healthy and affected by sarcoptic mange. In the Study I, an increase of serum amyloid protein type A (SAA) and in lower magnitude of alpha-1 acid glicoprotein (AGP) concentrations was observed, in correlation with the extent of the skin lesions caused by sarcoptic mange. Conversely, haptoglobin (Hp) concentration was not different between the healthy and infested ibexes. Since there is not an effective laboratory diagnostic method, in the Study II three enzyme-linked immunosorbent assays were evaluated for IgG detection against S. scabiei in Iberian ibex, and one of the three showed high specificity and sensitivity by using the avidin-biotin system, which allowed it to be validated. The Studies III and IV were carried out on Iberian ibexes with different alleles of the DRB1 gen of the major histocompatibility complex (MHC) class II, experimentally infested with S. scabiei. Although all the infested ibexes developed lesions compatible with sarcoptic mange, the clinical evolution varied from extensive lesions affecting most of the body surface to mild lesions and clinical recovering of the disease (Study III). However, such clinical differences seemed unrelated to MHC differences. The severely affected ibexes showed anaemia, possibly related to the inflammation caused by the mite, as well as neutrophilia and lymphopenia, probably due to secondary infections favoured by sarcoptic mange. Immunoglobulin G concentration also increased in agreement with the severity of the lesions. Finally, the Study IV addressed the genomic response of Iberian ibexes to the experimental infestation with S. scabiei. The severely affected Iberian ibexes showed an increase in the gene expression of pathways related to immunity and inflammation, agreeing with the exacerbated and non-effective generalized immune response induced by the mite and the response to secondary infections. Moreover, the Iberian ibexes that recovered showed an increase in the local skin expression of genes related with antigen presentation and T-lymphocytes activation. To summarize, sarcoptic mange induces both systemic and local changes in the Iberian Ibex, causing an increase in APP and antibodies, as well as haematological and local and systemic gene expression disorders. Although the causes of the differences found in the clinical evolution have not been completely elucidated, local skin cellular immunity may be key in controlling the infestation. Immunoglobulin G detection by ELISA can be a useful and effective diagnostic tool for sarcoptic mange in Iberian Ibex, while APP are a prognostic indicator.

Sarcoptic mange affects the common wombat (Vombatus ursinus) throughout its range. Prevalence of the disease is generally low, with less than 5% of wombats in a population affected. However, epizootics occur sporadically. Sarcoptic mange is less prevalent in southern hairy-nosed wombats (Lasiorhinus latifrons) but may be widespread. Sarcoptic mange has not been reported in the sole remaining population of northern hairy-nosed wombats (Lasiorhinus krefftii) at Epping Forest, Queensland. Whilst mange epizootics are sporadic, they have the potential to threaten the survival of small, remnant populations of wombats.

Vertebrate species are managed for many reasons, including their role as economically important predators or as carriers of disease. Successful management depends on the ability to predict the outcome of management actions on a species’ population dynamics. However, uncertainty in the models used to make such predictions can arise from multiple sources, including sampling error in vital rates, intraspecific demographic variation and unknown interspecific interactions. The red fox Vulpes vulpes provides a useful model organism for exploring such uncertainty, because management of this important predator and disease host is often ineffective, despite substantial sampling effort. By explicitly accounting for sampling error in survival and fecundity, confidence intervals for population growth rates were derived from published point estimates of red fox demographic data. Uncertainty in population growth rates was found to be high, requiring a quadrupling of sampling effort to halve the confidence intervals. Given the often poor justification for the choice of distribution used to model litter size, the influence of probability distributions on population model outcomes was tested. In this first comprehensive evaluation, estimates of quasi-extinction and disease control probabilities for three Canid species were found to be robust to litter size distribution choice. Demographic analyses of the red fox revealed a medium to fast life history speed and significant survival and fecundity contributions from juveniles to population growth. Intraspecific variation was detected within these spectra of demographic metrics: the first such demonstration for carnivores. Simulated data substitution between fox populations revealed that geographic proximity and similar levels of anthropogenic disturbance did not infer demographic similarity. Considering the sampling effort expended on the red fox, the species appears well-studied; yet, substantial limitations in data collection were identified. Compartment modelling of a sarcoptic mange outbreak in an urban fox population in Bristol, UK, revealed that disease transmission was frequency-dependent, consistent with contact rates being determined by social interactions rather than by population density. Individual-based modelling suggested that indirect transmission, genetic resistance and long-distance recolonisation were required to replicate the observed rapid spread of mange and subsequent population recovery. Thus, this first attempt to model mange dynamics in this canid provided novel insight into previously uncertain epidemiological and behavioural processes in the transmission of sarcoptic mange in the red fox.

Red foxes (Vulpes vulpes) have been identified as a key predator of the threatened piping plover (Charadrius melodus) along the U.S. Atlantic coast. However, little is known about coastal red fox ecology, making it difficult to create effective red fox management strategies in these settings. Here, we quantify aspects of red fox population, spatial, and dietary ecology and interactions with threatened piping plovers on Fire Island, New York. We conducted remote camera surveys, scat and sign surveys, den monitoring, and GPS tracking of red foxes on the island in 2015–2018. We used these data to estimate red fox occupancy, reproduction, survival, and population density. We used GPS data to investigate red fox space use, habitat selection, and responses to piping plover nest exclosure setup, pre-hatch pipping, and hatching. We used fecal dietary analyses and data from den prey item surveys to quantify the frequency of piping plover predation and to identify major prey items of red foxes on the island. Red fox occupancy remained high even after substantial decreases in abundance, population density, annual reproduction, and seasonal survival following 2 sarcoptic mange outbreaks. Within their home ranges, red foxes selected areas that were closer to vegetation during the daytime and twilight hours, but farther from vegetation at night. We did not find clear evidence that red foxes in our study area keyed in on piping plover nest exclosure setup, pipping, or hatching at the spatial scales considered in our comparisons, although fox penetration of and digging at exclosures was an issue in 2015 at Smith Point County Park. Items from Orders Rodentia (rodents, 43% of scats), Coleoptera (beetles, 38%), and Decapoda (crabs and other crustaceans, 29%) were most frequently found in 293 red fox scats examined. Skates (Family Rajidae, 89% of dens with food items) and Atlantic surf clams (Spisula solidissima, 67%) were found most frequently outside of dens. We did not find any identifiable piping plover remains in red fox scats or outside of dens. Our results suggest that direct interactions between red foxes and piping plovers during our study period and in our study area were less frequent than expected, but concurrent work by collaborators documented that the trap success of red foxes was negatively related to piping plover reproductive output during our study period. Lethal removal of red foxes is unlikely to eliminate them from shorebird nesting areas unless complete eradication of foxes from the island can be achieved. We recommend strategic vegetation management in and around piping plover nesting areas to reduce daytime resting areas and hunting cover for red foxes, and continued use of nest exclosures. We also recommend further investigation into indirect impacts of red foxes on piping plover populations, and into the possibility that anthropogenic food resources could be subsidizing the island's red fox population.
Doctor of Philosophy
Red foxes have been identified as a key predator of the piping plover, a small migratory shorebird that breeds along the U.S. Atlantic coast and is considered 'threatened' (at risk of becoming endangered and eventually disappearing) within the United States. The lack of information about red fox ecology in coastal settings has been a challenge for wildlife biologists tasked with reducing predation on piping plovers. We investigated red fox ecology, behavior, and interactions with piping plovers on Fire Island, New York. We used trail cameras, collected scat (feces), monitored dens, and tracked red foxes on the island with global positioning system (GPS) collars in 2015–2018. We used these data to estimate red fox distribution, litter sizes, survival rates, and population sizes. We used GPS data to estimate red fox territory sizes, describe habitat selection, and investigate responses to piping plover nest exclosure setup, pipping (a period before hatching during which chicks vocalize inside the eggs), and hatching. We dissected red fox scats and recorded prey items found outside of dens to determine what red foxes on the island were eating. The proportion of each study area used by red foxes remained high even after substantial decreases in abundance, population density, annual reproduction, and seasonal survival following 2 parasitic disease (sarcoptic mange) outbreaks. Within their territories, red foxes selected areas that were closer to vegetation during the daytime and twilight hours but farther from vegetation at night. We did not find clear evidence that red foxes in our study area keyed in on piping plover nest exclosure setup, pipping, or hatching, although fox penetration of and digging at exclosures was an issue in some years at a site not included in those comparisons. Rodents, beetles, and crustacean remains were found most frequently in red fox scats. Skates and surf clams were found most frequently outside of dens. We did not find any identifiable piping plover remains in red fox scats or outside of dens. Our results suggest that that direct interactions between red foxes and piping plovers may be less frequent than previously believed, but concurrent work by collaborators documented that the trap success of red foxes was negatively related to piping plover reproductive output during our study period. Lethal removal of red foxes is unlikely to eliminate red foxes from shorebird nesting areas unless all foxes on the island are removed. We recommend strategic vegetation removal in and around piping plover nesting areas to reduce daytime resting spots and hunting cover for red foxes, and continued use of nest exclosures. We also recommend further investigation into indirect impacts of red foxes on piping plover populations, and into the possibility that anthropogenic food resources could be subsidizing the island's red fox population.