Diagnosing and categorizing leprosy in live Eurasian red squirrels (Sciurus vulgaris) for management, surveillance, and translocation purposes

Schilling, Anna-Katarina; McCurdy, Kristen; Fish, Amy; Lurz, Peter W.W.; Geluk, Annemieke; Van Hooij, Anouk; Farish, Marianne; Mitchell, Malcolm; Stevenson, Karen; Meredith, Anna L.

Abstract

The presence of Mycobacterium lepromatosis and Mycobacterium leprae in Eurasian red squirrel (Sciurus vulgaris, ERS) carcasses throughout the British Isles, and leprosy as a disease, have recently been reported using histological and molecular diagnostic methods. In 2016, the first longitudinal study of ERS affected by leprosy was initiated. One of the main challenges was the reliable diagnosis of leprosy in live ERS, which is important for (a) welfare and case management and (b) surveillance or pretranslocation screening efforts. We explored diagnostic methods ranging from detailed clinical assessment and informative categorization of observed lesions, thermal imaging, serology (antiphenolic glycolipid-I antibody [αPGL-I] detection) to molecular methods (polymerase chain reaction [PCR]). For PCR the ear was established as the optimal sampling site. Based on the experiences from this 2-yr study we propose an objective categorization system for clinical lesions and a diagnostic framework for the combination of the diagnostic tools we found to be effective in live ERS: clinical assessment, αPGL-I serology, and PCR. Thermal imaging did not offer additional information for leprosy diagnostics in ERS. We propose an amended definition of leprosy lesions in ERS as “skin areas of local hair loss, in which a firm–rubbery, glossy swelling develops, that may ulcerate” and standardized terminology for describing ERS leprosy status. The information presented forms the basis of a consistent, reliable diagnostic and reporting system for leprosy cases in ERS.

• Journal Article Type: Article
• Acceptance Date: Jan 7, 2021
• Online Publication Date: Jun 11, 2021
• Publication Date: Jun 11, 2021
• Deposit Date: Apr 17, 2024
• Journal: Journal of Zoo and Wildlife Medicine
• Print ISSN: 1042-7260
• Publisher: American Association of Zoo Veterinarians
• Peer Reviewed: Peer Reviewed
• Volume: 52
• Issue: 2
• Pages: 648-659
• DOI: https://doi.org/10.1638/2020-0066