Serosurvey of Leishmania infantum in equids in different European countries.

The research investigates the prevalence and the potential risk factors of Leishmania infantum, a zoonotic disease, in equine populations across Europe. The study, involving 1364 equines from Spain, Italy, the United Kingdom, and Ireland, found a moderate and heterogeneous circulation of this pathogen in equids in southern Europe and highlighted the need for specific surveillance programs in these species.

Study Design and Methodology

• The research was undertaken to evaluate the prevalence and risk factors of L. infantum in equids in different European countries.
• The study involved 1364 equids, including 1005 horses, 240 donkeys, and 119 mules/hinnies from Spain, Italy, the United Kingdom, and Ireland
• Specimens were collected from these animals over the course of 12 years (2011 and 2023).
• The researchers wanted to identify the risk factors associated with seropositivity of L. infantum in these equine populations.
• The overall seroprevalence of L. infantum was determined using an indirect immunofluorescence test.

Major Findings

• The overall presence of L. infantum was found to be 9.8%, with significant variations based on species and geographical location.
• A significantly higher prevalence of anti-L. infantum antibodies was found in donkeys (27.9%) and mules/hinnies (21.1%) in contrast to horses (4.0%).
• Countrywise, equids from Italy showed significantly higher seropositivity (17.7%) compared to Spain (11.2%).
• On the contrary, no evidence of L. infantum was discovered in animals from Ireland and the United Kingdom.
• The variable ‘species’ (donkeys and mules/hinnies) was identified as a noticeable risk factor associated with L. infantum seropositivity.
• The study also reported for the first time L. infantum exposure in mules/hinnies in Europe.

Conclusions and Recommendations

• The findings suggest moderate and uneven prevalence of L. infantum in equids from southern Europe.
• The higher prevalence in donkeys and mules/hinnies compared to horses indicates a potential species-specific susceptibility for these animals.
• The research highlights the relevance of these findings given the potential role of equids in the L. infantum epidemiological cycle in southern Europe.
• The authors suggest the need to implement specific surveillance programs to prevent L. infantum spread among these species.
• This study is the largest of its kind to investigate the circulation of L. infantum in equids globally.