Background: Sheep scab is a highly contagious disease of sheep caused by the ectoparasitic mite Psoroptes ovis. The disease is endemic in the UK and has significant economic impact through its effects on performance and welfare. Diagnosis of sheep scab is achieved through observation of clinical signs e.g. itching, pruritis and wool loss and ultimately through the detection of mites in skin scrapings. Early stages of infestation are often difficult to diagnose and sub-clinical animals can be a major factor in disease spread. The development of a diagnostic assay would enable farmers and veterinarians to detect disease at an early stage, reducing the risk of developing clinical disease and limiting spread.
Methods: Serum samples were obtained from an outbreak of sheep scab within an experimental flock (n = 480 (3 samples each from 160 sheep)) allowing the assessment, by ELISA of sheep scab specific antibody prior to infestation, mid-outbreak (combined with clinical assessment) and post-treatment.
Results: Analysis of pre-infestation samples demonstrated low levels of potential false positives (3.8%). Of the 27 animals with clinical or behavioural signs of disease 25 tested positive at the mid-outbreak sampling period, however, the remaining 2 sheep tested positive at the subsequent sampling period. Clinical assessment revealed the absence of clinical or behavioural signs of disease in 132 sheep, whilst analysis of mid-outbreak samples showed that 105 of these clinically negative animals were serologically positive, representing potential sub-clinical infestations.
Conclusions: This study demonstrates that this ELISA test can effectively diagnose sheep scab in a natural outbreak of disease, and more importantly, highlights its ability to detect sub-clinically infested animals. This ELISA, employing a single recombinant antigen, represents a major step forward in the diagnosis of sheep scab and may prove to be critical in any future control program.
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http://dx.doi.org/10.1186/1756-3305-5-7 | DOI Listing |
Background: Sheep scab, caused by the highly infectious mite, is considered to be endemic in Northern Ireland, although little investigation has been reported. A pilot project was undertaken to engage farmers, confirm cases with diagnostic methods and identify specific barriers to control, with the aim of informing future control programmes.
Methods: Through farmers self-reporting suspected outbreaks, on-farm risk assessments and clinical investigations were carried out by the farm's veterinary surgeon, who utilised light microscopy and serological testing to diagnose scab.
Front Vet Sci
December 2024
Yunnan Tropical and Subtropical Animal Virus Disease Laboratory, Yunnan Academy of Animal Husbandry and Veterinary Sciences, Kunming, Yunnan, China.
Contagious Eczema (CE), caused by ORFV, impacts sheep and goats globally, with severe symptoms and economic losses. The ORFV situation in Yunnan, China, was unclear before 2021-2023 study. Eleven scab samples from goats on small farms in three Yunnan municipalities were collected.
View Article and Find Full Text PDFPrev Vet Med
December 2024
James Hutton Institute, Craigiebuckler, Aberdeen AB15 8QH, UK.
Vet World
March 2024
Department of Rural Development and Agrarian Reform, Private Bag X6012, Port Elizabeth 6001, South Africa.
Background And Aim: Sheep scab is one of the most contagious diseases of sheep found in rural communities worldwide and is a major health and welfare concern for sheep farming. Information on the attitudes of communal farmers to sheep scab remains speculative in the Eastern Cape Province. This study aimed to investigate knowledge, attitudes, and practices related to the prevalence of sheep scab among communal sheep farmers in Eastern Cape Province, South Africa.
View Article and Find Full Text PDFVet Rec
May 2024
School of Biological Sciences, University of Bristol, Bristol, UK.
Background: Ovine psoroptic mange (sheep scab), caused by an infestation of the mite Psoroptes ovis, leads to clinical disease, economic loss and severely compromised animal welfare. Here, a community-based approach to the management of scab in three high-risk areas of England is described.
Methods: For each of the 254 farms included in the study, an initial survey of their clinical sheep scab history was followed up by a blood test (ELISA) to detect the presence of antibodies to P.
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