Serosurveillance of Leishmania infantum in Zoo-Kept Animals in Spain.

INTRODUCTION

Leishmaniosis is a sand fly-borne zoonosis mainly caused by Leishmania infantum in Europe. Exposure to this protozoan has been widely reported in many domestic and wild species. However, epidemiological surveys evaluating the circulation of L. infantum in zoo-kept animals remain limited. This large-scale study aims to evaluate the seroprevalence of L. infantum in zoo-kept species in Spain as well as alterations in serum protein levels in L. infantum-seropositive individuals, to identify potential risk factors associated with L. infantum exposure, and to assess the dynamics of seropositivity in animals longitudinally sampled during the study period.

METHODS

Between 2007 and 2023, serum samples from 429 zoo-kept animals belonging to 72 species were collected in nine zoos in Spain using convenience sampling. Additionally, 29 of these individuals from six of the tested zoos were also longitudinally sampled.

RESULTS

Anti-L. infantum antibodies were detected in 22 (5.1%; 95% CI: 3.0-7.2) of the 429 animals using an in-house ELISA, as well as in 13.9% (10/72) and 66.7% (6/9) of the species and zoos tested, respectively. Serum protein electrophoresis analyses revealed that polyclonal gammopathy was the most common alteration in L. infantum-seropositive individuals. Three animals longitudinally surveyed seroconverted throughout the study period. The multivariate analysis identified the family Canidae as a risk factor for L. infantum exposure.

CONCLUSIONS

Our results indicate a moderate, widespread and endemic circulation of L. infantum in zoo-kept animals from Spain, which may be of animal health, conservation, and public health concern. Surveillance programs and control measures should be implemented in zoos to minimise the exposure of these species to Leishmania spp., particularly in hotspot areas.