Eco‐epidemiology of equine piroplasmosis and its associated tick vectors in Europe: A systematic literature review and a meta‐analysis of prevalence

Abstract

When studying a vector-borne disease, an eco-epidemiological approach is vital for a comprehensive understanding of how the pathogen circulates amongst populations.Equine piroplasmosis (EP), a tick-borne disease caused by the protozoans Babesia caballi and Theileria equi, is endemic in the Mediterranean basin of Europe and causes both animal health and economic issues for the equine sector. With no vaccine available, defining the episystem of the disease can help to identify which components of the host-pathogen-vector-environment system to target to improve preventive measures. In this systematic literature review, we collected relevant data on the ecoepidemiology of EP in Europe. The 62 studies remaining after the selection procedure explored potential vectors, indicators of parasite circulation and putative risk factors of EP. Eight hard tick species were identified as potential vectors of one or both piroplasm species. Meta-analyses were then conducted on prevalence and seroprevalence data in equids in European countries, demonstrating an estimated seroprevalence of 30% and 8% and prevalence of 25% and 2% for T. equi and B. caballi, respectively. Finally, herd management practices and environmental risk factors analysed in studies showed no real consensus between studies, but revealed a general trend highlighting age and exposure to ticks as risk factors, and vaccination as a protective factor. Through this study, we point out that only a few studies have focused on disease management practices and even fewer have studied the effect of environmental parameters on equid infections. Further investigation in these areas is required to better characterize the eco-epidemiology of EP and risk factors associated with this disease.

Spatial and Temporal Circulation of Babesia caballi and Theileria equi in France Based on Seven Years of Serological Data

“…The overall higher seroprevalence against T. equi compared with B. caballi was reported in other European countries, such as Spain or Italy, following ELISA or IFAT detection tests [14,33,34]. It may be linked to the fact that lifelong T. equi infections are currently suspected in equids, even after treatment [1,2,9,35], with persistent low parasitaemia leading to persistent antibody titres [36].…”

“…Regarding the co-occurrence of antibodies against T. equi and B. caballi in horses, our results highlighted a significant positive association. This may be likely explained by the fact that the two piroplasm species share vectors [3,14], with possible co-infection in ticks leading to co-infection in horses, or sequential contamination. Further studies on co-infections by both piroplasm species are needed, and experimental studies focusing on co-infections in both hosts and vectors should be conducted to explore the potential facilitation of infection between B. caballi and T. equi.…”

“…B. caballi and T. equi infections have been described worldwide, and are enzootic in many countries including several European countries bordering the Mediterranean such as France [4,14]. However, to our knowledge, only very few studies have been published on the epidemiology of these infections in France since the end of the 1990s and none of them have assessed the spatio-temporal trends in the circulation of these piroplasms [15][16][17][18][19].…”

Seroprevalence of Anti-Theileria equi Antibodies in Horses from Three Geographically Distinct Areas of Romania

“…The disease is endemic in most parts of the world and constitutes a risk for the welfare of equines. Its significance resides in the economic losses caused by the negative impact on international trade, namely the transportation restrictions imposed by non-endemic countries [9][10][11][12].…”

Experimental Infection of Ticks: An Essential Tool for the Analysis of Babesia Species Biology and Transmission

“…Ovine babesiosis due to Babesia ovis and Babesia motasi is considered as the most critical blood-borne parasitic disease of small ruminants in tropical and nontropical regions (occurring in South-eastern Europe, North Africa, and Asia) [6]. In equids, Babesia caballi is (with Theileria equi and Theileria haneyi) the agent of equine piroplasmosis known to be endemic in several countries of Africa, Asia, the Americas, and mainly in the Mediterranean basin for Europe [7][8][9]. The disease represents a significant animal health issue and causes notable economic losses for the equine industry.…”