A systematic review on leptospirosis in cattle: A European perspective

Abstract

Leptospirosis is a zoonotic disease which is globally distributed and represents a classic One Health issue that demands a comprehensive understanding of the hosts, transmission paths, and risk factors of transmission. Bovine leptospirosis often results in economic losses through its severe impact on reproduction performance while it threatens human health at human-cattle-environment interfaces. However, a clear analysis of the disease characteristics in European cattle is currently lacking. The objective of this review was to summarise the current knowledge on the epidemiology of bovine leptospirosis in Europe. We conducted a systematic literature review, screening four electronic databases, and filtered articles published between 2001 and 2021, in English, German, and French. Sixty-two articles were ultimately included in the review. The seroprevalence of leptospirosis in cattle was remarkably variable among studies, probably reflecting local variations but also heterogeneity in the study designs, laboratory methods, and sample sizes. Risk factors positively associated with the disease were diverse, related to local, environmental, and climatic parameters as well as farming practices. The most reported circulating Leptospira serogroups in European cattle were Sejroe (58.5%), Australis (41.5%), Grippotyphosa (41.5%), Icterohaemorrhagiae (37.7%), and Pomona (26.4%), which have also been associated with human infections worldwide. Abortion (58.6%) and fertility disorders (24.1%) were the most frequently reported signs of leptospirosis in European cattle and were generally associated with chronic infections. This work highlights several research gaps, including a lack of harmonisation in diagnostic methods, a lack of large-scale studies, and a lack of molecular investigations. Given that predictions regarding the climatic suitability for leptospirosis in Europe suggest an increase of leptospirosis risk it is important to raise awareness among stakeholders and motivate an integrated One Health approach to the prevention and control of this zoonotic disease in cattle and humans.

Keywords: Cattle; Epidemiology; Europe; Leptospira; Leptospirosis; Systematic review.

Fig. 1

Review process flow chart.

Fig. 2

Circulating Leptospira serogroups in European cattle (determined by MAT) reported in the included papers, 2001-2021. X-axis represents years of publication.

Fig. 3

Sankey diagram showing the type of production, the risk factor categories, the risk factors investigated, and the direction of the association between risk factors and Leptospira-infection in cattle, Europe, 2001-2021. Only studies that have performed a statistical analysis (n = 18) are included and only significant risk factors are displayed. Colours represent the risk categories. The y-axis represents the number of times a risk factor was tested across the 18 studies; x-axes represent the production type, risk category, and statistical association between the risk factor and the presence of Leptospira. Association may be positive or negative; “significant” means that the association is statistically significant, but no direction is provided.