Leprosy in red squirrels in the UK

• Published in: Veterinary record 2019-03, Vol.184 (13), p.416-416
• Main Authors: Schilling, Anna-Katarina, Del-Pozo, Jorge, Lurz, Peter W. W., Stevenson, Karen, Avanzi, Charlotte, Shuttleworth, Craig M., Cole, Stewart T., Meredith, Anna L.
• Format: Article
• Language: English
• Subjects: Bears; Bird watching; Deoxyribonucleic acid; DNA; Leprosy
• ISSN: 0042-4900; 2042-7670
• DOI: 10.1136/vr.l1385

Additionally, an alternative causative agent, Mycobacterium leprae, was identified in red squirrels exclusively on Brownsea Island.3 While it is currently unknown whether M lepromatosis has ever caused human disease in Europe, the M leprae strain identified in the Brownsea Island squirrels is highly related to strains that caused leprosy in medieval Europeans.3, 4 Thus, a historical anthroponotic transmission of the bacteria to squirrels may have occurred, as is presumed for nine-banded armadillos (Dasypus novemcinctus) in the Americas.5 As part of our ongoing leprosy studies we screened pinna tissue samples from 78 red squirrels from the Isle of Arran collected between 2015 and 2018, and from 121 frozen squirrel carcases collected between 1983 and 2018 in north-west Wales, using established, previously described PCR techniques.3 Both study areas have been the focus of population ecology research.6, 7 We identified M leprae DNA in four animals on the Isle of Arran and in two animals in Wales We identified M leprae DNA in four animals on the Isle of Arran (5.1 per cent) and in two animals in Wales (1.7 per cent), but did not find M lepromatosis DNA in any of the samples. Unfortunately, the amount of M leprae DNA extracted was too low to enable sequence comparisons with the Brownsea Island strain.3 No autochthonous cases of human leprosy have occurred in Britain since the 1950s.8 Therefore, the presence of M leprae and M lepromatosis in red squirrels in the British Isles does not appear to pose an increased risk to human health. Efforts to identify either M leprae or M lepromatosis in Eurasian red squirrels outside the British Isles have so far been unsuccessful.9 Continued monitoring of the epidemiological situation will help us better understand leprosy dynamics between people and animals in disease endemic countries.References 1 Meredith A, del-Pozo J, Smith S, et al.