Occurrence of Leishmania infantum in Wild Mammals Admitted to Recovery Centers in Spain

Abstract

Zoonotic leishmaniasis caused by Leishmania infantum is distributed worldwide and affects humans and domestic and wild mammals. In Europe, specifically in the Mediterranean basin, leishmaniasis is endemic due to the concurrence of the phlebotomine vectors and reservoir mammals, including carnivorous wildlife species and other less studied wild species. In this article, spleen, skin, and eye or oral swabs taken from 134 wild mammals admitted to five wildlife recovery centers in Spain were used. PCR employing fragments of the Repeat region, ITS1, and SSUrRNA were used for detection, and positive samples were processed for sequencing. L. infantum was detected in three out of the nine species analyzed, including European hedgehog, European badger, and red squirrel, with percentages ranging from 11.53 to 35.71%, depending on the species. Most of the species showed higher percentages of positivity in spleen samples than in skin samples. A small number of animals from the remaining six species tested negative, including Algerian hedgehog, stone marten, least weasel, garden dormouse, western polecat, and Egyptian mongoose. Hedgehogs and badgers are good candidates for consideration as epidemiological sentinels and pose a higher risk as potential reservoirs of leishmaniasis based on their percentage of infection and wide distribution.

Keywords: European badger; European hedgehog; L. infantum; PCR; red squirrel; wild mammals.

Figure 1

Map showing the distribution of species that tested positive for L. infantum in Spain (dotted areas). Areas colored in orange are recognized as having endemic leishmaniasis, according to ECDC, 2022. (a) Distribution areas of European hedgehog; (b) distribution areas of European badger; (c) distribution areas of red squirrel. Red stars indicate the origin of the samples used in the present study.

Figure 2

Phylogenetic trees of SSUrRNA (a) and ITS1 (b) fragments. The trees were constructed by applying Neighbor-Joining and BioNJ algorithms to a matrix of pairwise distances estimated using the Tamura–Nei model and selecting the superior log likelihood value. The trees are drawn to scale, with branch lengths measured based on the number of substitutions per site. A bootstrap of 2000 replicates was employed.