Problems in Diagnosing Scabies, a Global Disease in Human and Animal Populations

Abstract

SUMMARY Scabies is a worldwide disease and a major public health problem in many developing countries, related primarily to poverty and overcrowding. In remote Aboriginal communities in northern Australia, prevalences of up to 50% among children have been described, despite the availability of effective chemotherapy. Sarcoptic mange is also an important veterinary disease engendering significant morbidity and mortality in wild, domestic, and farmed animals. Scabies is caused by the ectoparasitic mite Sarcoptes scabiei burrowing into the host epidermis. Clinical symptoms include intensely itchy lesions that often are a precursor to secondary bacterial pyoderma, septicemia, and, in humans, poststreptococcal glomerulonephritis. Although diagnosed scabies cases can be successfully treated, the rash of the primary infestation takes 4 to 6 weeks to develop, and thus, transmission to others often occurs prior to therapy. In humans, the symptoms of scabies infestations can mimic other dermatological skin diseases, and traditional tests to diagnose scabies are less than 50% accurate. To aid early identification of disease and thus treatment, a simple, cheap, sensitive, and specific test for routine diagnosis of active scabies is essential. Recent developments leading to the expression and purification of S. scabiei recombinant antigens have identified a number of molecules with diagnostic potential, and current studies include the investigation and assessment of the accuracy of these recombinant proteins in identifying antibodies in individuals with active scabies and in differentiating those with past exposure. Early identification of disease will enable selective treatment of those affected, reduce transmission and the requirement for mass treatment, limit the potential for escalating mite resistance, and provide another means of controlling scabies in populations in areas of endemicity.

Pathology of Sarcoptic Mange in Red Foxes (Vulpes Vulpes): Macroscopic and Histologic Characterization of Three Disease Stages

“…A particularly severe form, characterized by thick crusts on large parts of the body, is typically observed in free-ranging Spanish ibex (Capra pyrenaica, LeonVizcaino et al, 1999), Eurasian lynx (Lynx lynx; Ryser-Degiorgis et al, 2002), and wombats (Vombatus ursinus; Skerratt, 1998). Similar lesions sometimes occur in humans (Walton and Currie, 2007). Histo-logically, mange is characterized by dermatitis with hyperkeratosis and epidermal hyperplasia but the quantity, quality, time of appearance, and duration of the cellular response differ among hosts (Bornstein et al, 2001;Skerratt, 2003).…”

“…The macroscopic and histologic picture of type B lesions is indeed congruent with the chronic dermatitis described in immunocompromised animals and humans. However, this mange form is also commonly observed in naïve wild animal populations and in humans unable to respond to the itching, and in humans with mental retardation or suspected genetic predisposition (Walton and Currie, 2007). Thus, multiple factors seem to determine the disease course.…”

Characterization of a Serine Protease Homologous to House Dust Mite Group 3 Allergens from the Scabies Mite Sarcoptes scabiei

“…prisons and long term care facilities. Scabies is a major public health problem in socially disadvantaged communities, such as those found in indigenous populations and in developing countries (1,2). Infestation occurs when the adult female mite burrows in the skin.…”

Evaluation of Acaricidal Effect of Ethnoveteinary Medicinal Plant by in vivo and in vitro against Sarcoptes scabiei var. caprae of Infected Goats in North Shoa, Oromia Regional State, Ethiopia

“…caniculi) (Sarcoptes scabies varovis) [54,55] and ticks (Boophilus microplus) [56]. The pesticide activity of this fixed oil is generally thought to be due to azadirachtin, which is a well-known potent insecticide [57].…”