Sarcoptic mange outbreak decimates South American wild camelid populations in San Guillermo National Park, Argentina

Human scabies and sarcoptic mange in northeast Brazil: Results from a rapid assessment method covering an entire state

Scabies is a neglected tropical disease and has been highlighted as a target for control. Sarcoptic mange affects animals, but mange is also considered a zoonosis. We present rapid assessment data on scabies and sarcoptic mange collected from key informants via a web-based questionnaire in Ceará State (1265 data entries). A total of 181/184 (98.3%) municipalities reported the occurrence of human scabies; 149 (80.9%) current occurrence; 168 (91.3%) severe cases; and 113 (61.4%) severe cases currently. Sarcoptic mange was reported from 149/184 (80.9%) municipalities, and severe mange from 128 (69.9%), most commonly in dogs (117 municipalities), cats (79), pigs (17), cattle (15), horses (15), and goats (2). Respondents from 171 (92.9%) municipalities observed seasonality of occurrence. Scabies and sarcoptic mange are important public health issues in a northeast Brazilian state. The wide distribution of severe cases requires an integrated One Health approach effectively and sustainably to reduce the disease burden.

Effective treatment of sarcoptic mange in an alpaca (Vicugna pacos) using fluralaner: a case report

South American Camelids, including alpacas, have gained popularity in Europe as pets and prized wool sources. Skin health concerns, particularly mite infestations, have emerged as a notable problem in these animals. Sarcoptic mange can lead to severe itching, papules, and chronic symptoms such as alopecia, crusts, and emaciation if left untreated. This case report documents a 2-year-old female alpaca suffering from sarcoptic mange. Despite initial treatment with ivermectin, its condition worsened, leading to severe weight loss, abortion, and a continued presence of mites. Considering the lack of effective treatments for sarcoptic mange in alpacas and the unavailability of registered drugs for this species in Italy, fluralaner, a drug previously used in other animal species, has been administered orally at a dosage of 5 mg/kg. Within a week after the treatment with fluralaner, the patient exhibited significant improvement, including the resolution of itching, healing of skin lesions, and an increase in appetite. Follow-up skin scrapings confirmed the absence of mites, and the patient's condition continued to improve. Fluralaner demonstrated to be a highly effective and fast-acting treatment for sarcoptic mange in alpacas, offering potential economic benefits attributed to its single-dose administration.

Vicuña antipredator diel movement drives spatial nutrient subsidies in a high Andean ecosystem

Large animals could be important drivers of spatial nutrient subsidies when they ingest resources in some habitats and release them in others, even moving nutrients against elevational gradients. In high Andean deserts, vicuñas (Vicugna vicugna) move daily between nutrient-rich wet meadows, where there is abundant water and forage but high risk of predation by pumas (Puma concolor), and nutrient-poor open plains with lower risk of predation. In all habitats, vicuñas defecate and urinate in communal latrines. We investigated how these latrines impacted soil and plant nutrient concentrations across three habitats in the Andean ecosystem (meadows, plains, and canyons) and used stable isotope analysis to explore the source of fecal nutrients in latrines. Latrine soils had higher concentrations of nitrogen, carbon, and other nutrients than did nonlatrine soils across all habitats. These inputs corresponded with an increase in plant quality (lower C:N) at latrine sites in plains and canyons, but not in meadows. Stable isotope mixing models suggest that ~7% of nutrients in plains latrines originated from vegetation in meadows, which is disproportionately higher than the relative proportion of meadow habitat (2.6%) in the study area. In contrast, ~68% of nutrients in meadow latrines appear to originate from plains and canyon vegetation, though these habitats made up nearly 98% of the study area. Vicuña diel movements thus appear to concentrate nutrients in latrines within habitats and to drive cross-habitat nutrient subsidies, with disproportionate transport from low-lying, nutrient-rich meadows to more elevated, nutrient-poor plains. When these results are scaled up to the landscape scale, the amount of nitrogen and phosphorus subsidized in soil at plains latrines was of the same order of magnitude as estimates of annual atmospheric nitrogen and phosphorus deposition for this region (albeit far more localized and patchy). Thus, vicuña-mediated nutrient redistribution and deposition appears to be an important process impacting ecosystem functioning in arid Andean environments, on par with other major inputs of nutrients to the system.

Density independent decline from an environmentally transmitted parasite

Invasive environmentally transmitted parasites have the potential to cause declines in host populations independent of host density, but this is rarely characterized in naturally occurring populations. We investigated (1) epidemiological features of a declining bare-nosed wombat (Vombatus ursinus) population in central Tasmania owing to a sarcoptic mange (agent Sarcoptes scabiei) outbreak, and (2) reviewed all longitudinal wombat-mange studies to improve our understanding of when host population declines may occur. Over a 7-year period, the wombat population declined 80% (95% CI 77-86%) and experienced a 55% range contraction. The average apparent prevalence of mange was high 27% (95% CI 21-34), increased slightly over our study period, and the population decline continued unabated, independent of declining host abundance. Combined with other longitudinal studies, our research indicated wombat populations may be at risk of decline when apparent prevalence exceeds 25%. This empirical study supports the capacity of environmentally transmitted parasites to cause density independent host population declines and suggests prevalence limits may be an indicator of impending decline-causing epizootics in bare-nosed wombats. This research is the first to test effects of density in mange epizootics where transmission is environmental and may provide a guide for when apparent prevalence indicates a local conservation threat.

Sarcoptic mange is an emerging threat to biodiversity in the Qinling Mountains in China

Sarcoptic mange, a disease caused by the burrowing mite Sarcoptes scabiei, is globally endemic and an emerging threat to wildlife. Although many studies have shown that wildlife diseases play key roles in biodiversity conservation, knowledge about sarcoptic mange is still insufficient. In this study, we aim to improve the understanding of the impacts of sarcoptic mange on wildlife populations, the mechanisms involved in its eco-epidemiology and the associated risks to public and ecosystem health by investigating mass death events in gorals and serows in the Qinling Mountains. We conducted interviews with practitioners and local people in the central Qinling Mountains. From the same locations, we collected 24 cutaneous samples from various animals and surveillance data from infrared cameras. Pathological, parasitological and microbiological examinations of the samples were performed. Mite-induced cutaneous lesions, mites and eggs were observed in samples from dead gorals and one dead serow but not in other species. Molecular analysis confirmed the mites to be S. scabiei and shared the same cox 1 genotype. The data obtained from the interviews and infrared cameras indicated that the death of wildlife was related to sarcoptic mange infection and that there had been a decrease in the goral population since the outbreak of the disease. We confirmed that sarcoptic mange was the major cause of the mass death events and may have spread from the western to eastern Qinling Mountains. Based on our findings, we propose several protection strategies to help preserve biodiversity in the Qinling Mountains.

Sarcoptic mange outbreaks in vicuñas (Cetartiodactyla: Camelidae): A scoping review and future prospects

Sarcoptic mange is considered an emerging disease-causing countless epizootics and significantly affecting wild mammals worldwide. The vicuña (Vicugna vicugna) is a medium-sized South American wild camelid inhabiting Andean ecosystems, where several populations are live-sheared by Andean peasant communities as a way of providing an economic income to the people while promoting vicuña conservation. Institutions and scientists have shown concern for the impact and extent of sarcoptic mange in several vicuña populations across their range, as well as the lack of consistent knowledge about this disease in the species. Here, we perform a review about sarcoptic mange distribution throughout the vicuña's native range, evidence of effects of age and sex, the modes of transmission and the veterinary treatments employed. The review retrieved a few scientific papers, but found several reports and academic studies mostly considered as 'grey literature'. Mange was recorded across the entire native vicuña range (Argentina, Bolivia, Chile and Peru). Mange prevalence varied across vicuña studies (up to 60% prevalence in some populations) and severely affected a number of populations, being an important source of mortality. Mange was reported as more frequent in adults than in offspring. The modes of mange transmission remain unclear, although direct transmission between infected and healthy animals seems to be the most likely, including the transmission between domestic camelids and vicuñas. Regarding the treatments employed, ivermectin was the most frequently used. We further identified several gaps in knowledge and point to future research lines, which seek to promote both species conservation and the maintenance of live-shearing vicuñas under sustainable approaches in low-income Andean peasant communities.

Occurrence of sarcoptic mange in free-ranging vicuñas (Vicugna vicugna) of the Andean high plateau region of Argentina

Free-ranging vicuñas (Vicugna vicugna) are handled in some areas of the Andean high plateau region following an ancestral practice known as chaku, which consists in their transient capture and shearing of their fiber for commercialization. In this study, 807 vicuñas captured during 12 chaku events that took place in 2019 in the province of Jujuy, Argentina, were examined for typical mange skin lesions. Twenty-eight of the examined vicuñas presented alopecia with erythema, exudation, hyperkeratosis, and/or bleeding scarred lesions, mostly in the chest, rear and front legs, and inguinal zone. Most of the cases (82%) appeared in Laguna Cucho at 4900 masl, where 23% of the animals presented these skin reactions. Microscopic evaluation of skin scrapings revealed the presence of a great number of 0.1- to 0.4-mm-long mites of different life cycle stages, morphologically compatible with the species Sarcoptes scabiei. This etiological agent was confirmed by PCR amplification and sequencing of a cox-1 species-specific segment. Histopathological examination of skin biopsies showed extensive infiltration of the dermis with lymphocytes, neutrophils and eosinophils, hyperplasia at different stages, epidermis degeneration, and hyperkeratosis. This is the first characterization of sarcoptic mange in free-ranging vicuñas by clinical examination, mite morphology, histopathological studies, and molecular confirmation in the region. Mange hampers the welfare of vicuñas and the economy of the local communities that organize chaku events since infested vicuñas cannot be sheared. Its long-term effects are unknown but it might affect the fitness and survival of this iconic South American camelid.

Cascading effects of a disease outbreak in a remote protected area

Disease outbreaks induced by humans increasingly threaten wildlife communities worldwide. Like predators, pathogens can be key top-down forces in ecosystems, initiating trophic cascades that may alter food webs. An outbreak of mange in a remote Andean protected area caused a dramatic population decline in a mammalian herbivore (the vicuña), creating conditions to test the cascading effects of disease on the ecological community. By comparing a suite of ecological measurements to pre-disease baseline records, we demonstrate that mange restructured tightly linked trophic interactions previously driven by a mammalian predator (the puma). Following the mange outbreak, scavenger (Andean condor) occurrence in the ecosystem declined sharply and plant biomass and cover increased dramatically in predation refuges where herbivory was historically concentrated. The evidence shows that a disease-induced trophic cascade, mediated by vicuña density, could supplant the predator-induced trophic cascade, mediated by vicuña behaviour, thereby transforming the Andean ecosystem.