Global prevalence of equine piroplasmosis: A systematic review and meta-analysis of evidence from 2020-2025.

Overview

• This study systematically reviews and analyzes global data from 2020 to 2025 to estimate how common equine piroplasmosis is worldwide and identifies factors influencing its prevalence.
• The research highlights the significant presence of different causative agents and the variability across regions, emphasizing the need for better monitoring and control strategies.

Purpose and Background

• Equine piroplasmosis is a tick-borne disease affecting horses and related animals, caused primarily by parasites like Theileria equi, Babesia caballi, and Theileria haneyi.
• This disease impacts animal health, reduces productivity, and restricts international movement of equines due to its infectious nature.
• The study aims to synthesize recent global data to understand the current prevalence, trends, and risk factors associated with the disease.

Methodology

• The researchers conducted a systematic review and meta-analysis following PRISMA 2020 guidelines to ensure transparent and replicable study selection and data synthesis.
• Databases searched included major scientific repositories such as PubMed, Scopus, Web of Science, and others, covering literature from 2020 to 2025.
• A total of 95 studies met inclusion criteria and were included in the meta-analysis.
• Random-effects meta-analyses were used to calculate pooled prevalence estimates, accommodating heterogeneity among included studies.
• Subgroup analyses and meta-regressions helped explore sources of heterogeneity and temporal trends.
• Analyses were conducted using RStudio software (version 4.6.0), with assessments for publication bias to evaluate the robustness of findings.

Key Findings

• The pooled prevalence of active infection with Theileria equi was found to be approximately 25.21%, while seroprevalence (evidence of exposure or past infection) for this parasite was higher at 30.96%, suggesting ongoing exposure and infection in populations worldwide.
• For Babesia caballi, active infection had a pooled prevalence of 4.60%, with seroprevalence at 10.90%, indicating a less frequent but still significant presence.
• Theileria haneyi showed an active infection prevalence of 12.18%, contributing to the disease burden.
• All prevalence estimates exhibited substantial heterogeneity (I² > 90%), denoting large variations between study results.
• Such heterogeneity likely derives from differences in:
  • Sampling periods and sample sizes
  • Geographic locations and regional characteristics
  • Diagnostic methods employed (e.g., molecular vs. serological tests)
  • Host demographics such as age, species, and management practices
• Meta-regression revealed a statistically significant increasing trend in prevalence of T. equi over time (p < 0.05), highlighting potential worsening or better detection in recent years.

Implications

• The persistent and widespread high prevalence of equine piroplasmosis, especially strains caused by T. equi, represents a continued risk for equine health globally.
• Marked heterogeneity emphasizes the need for:
  • Standardized surveillance frameworks to enable comparable epidemiological data collection worldwide
  • Harmonized and reliable diagnostic protocols to accurately detect and differentiate causative agents
  • Integrated vector control strategies to reduce tick populations and interrupt transmission
• These targeted approaches could improve disease management, reduce economic losses, and facilitate safer international equine movement.

Conclusion

• This systematic review and meta-analysis provide comprehensive updated evidence on the global burden of equine piroplasmosis from 2020 to 2025.
• Findings reinforce the importance of enhanced monitoring, diagnostic harmonization, and vector control to mitigate the disease’s global impact.