Surveillance for Leptospira sp. in native and invasive shrews in Ireland compared with cohabitating shrews in France

Authors: IMLAU, MICHELLE - University College Dublin; BROWNE, JOHN - University College Dublin; BROWETT, SAMUEL - South East Technological University; MCDEVITT, ALLAN - Atlantic Technological University; MCMAHON, BARRY - University Of Dublin; Nally, Jarlath; JAHNS, HANNE - University Of Dublin

Submitted to: Journal of Wildlife Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/26/2024
Publication Date: 5/9/2025
Citation: Imlau, M., Browne, J.A., Browett, S.S., Mcdevitt, A.A., Mcmahon, B.J., Nally, J.E., Jahns, H. 2025. Surveillance for Leptospira sp. in native and invasive shrews in Ireland compared with cohabitating shrews in France. Journal of Wildlife Diseases. 61(2):477-482. https://doi.org/10.7589/JWD-D-24-00084.
DOI: https://doi.org/10.7589/JWD-D-24-00084

Interpretive Summary: Pathogenic species of Leptospira cause leptospirosis, a global disease that is transmitted from animals to humans. Leptospires survive in the kidney of domestic and wild animal species, from where they are excreted via urine; contact with infected urine, or water contaminated with infected urine, can result in disease since pathogenic leptospires can penetrate breaches of the skin, or mucosal surfaces. In a previous study, we identified a new species of pathogenic Leptospira from an invasive mammal in Ireland, the great white toothed shrew (GWTS). In this study, we investigated the prevalence of Leptospira species, including the new species named L. tipperaryensis, and its potential impact on the health of GWTS as well as the native pygmy shrew. Shrews from Belle Ile, France were similarly examined as a species and habitat control group. No Leptospira were detected in renal tissues from shrews sampled in Ireland and in general, there was no significant renal pathology. In contrast, 34.6% of shrews from France were identified as carriers of Leptospira sp. with an associated chronic nephritis. Results indicate that there is no negative impact by L. tipperaryensis or other Leptospira species on the health and distribution of the GWTS and the pygmy shrew in Ireland, and that onward transmission within the shrew population appears unlikely.

Technical Abstract: Leptospirosis is a complex and often underestimated global bacterial disease which continues to be of zoonotic concern. It is difficult to diagnose, has an unclear pathogenesis and several new species of the genus Leptospira have been discovered in recent years. The impact of these species on animal health are unknown. In 2013, the new L. tipperaryensis was first identified in greater white-toothed shrews (GWTS - Crocidura russula), an invasive species found in Ireland that displaces the native pygmy shrew (Sorex minutus). This study investigates the prevalence of Leptospira species, including L. tipperaryensis, and its potential impact on the health of GWTS and pygmy shrews using histopathology, IHC and PCR on renal tissues (n =212). Shrews from Belle Ile, France were similarly examined as a species and habitat control group (n = 81). No Leptospira were detected in renal tissues from shrews sampled in Ireland and in general, there was no significant renal pathology. In contrast, 34.6% (28/81) of shrews from Belle Ile were identified as carriers of Leptospira sp. with an associated chronic nephritis. Results indicate that there is no negative impact by L. tipperaryensis or other Leptospira species on the health and distribution of the GWTS and the pygmy shrew in Ireland, and that onward transmission within the shrew population appears unlikely.