Global seroprevalence and epidemiological patterns of equine viral arteritis from 1968 to 2025: A systematic review and meta-analysis.

Overview

• This research article presents a systematic review and meta-analysis aimed at determining the global seroprevalence of equine viral arteritis (EVA) from 1968 to 2025 and understanding the epidemiological patterns and sources of variability across studies.
• The study synthesizes data from multiple regions and examines factors influencing infection rates, highlighting significant heterogeneity and the need for coordinated control strategies worldwide.

Introduction to Equine Viral Arteritis (EVA)

• EVA is an infectious viral disease that affects equids, such as horses, with implications for animal health and economic consequences due to impacts on reproductive efficiency.
• The disease also affects international equine trade, given regulations designed to prevent its spread between countries.
• Despite numerous studies focusing on specific regions, a comprehensive global understanding of EVA’s seroprevalence (the proportion of animals with antibodies against EVA) had been lacking prior to this research.

Objectives and Scope

• To calculate the pooled global seroprevalence of EVA using data from diverse studies spanning nearly six decades (1968-2025).
• To explore epidemiological heterogeneity—including differences by species, geographic region, diagnostic methods, and time periods—in EVA seroprevalence.
• To identify sources of variability that could inform better surveillance and control programs.

Methodology

• Systematic Review:
  • Followed PRISMA 2020 guidelines to ensure transparency and reproducibility in study identification and selection.
  • Five independent reviewers screened studies from multiple databases like PubMed, Scopus, ScienceDirect, Springer Nature, the Cochrane Library, ProQuest, CABI Digital Library, and Google Scholar.
  • Included studies published over a wide time range, from 1968 to projected 2025.
• Data Extraction and Mapping:
  • Used Microsoft Excel for detailed data extraction and organization.
  • Applied QGIS v3.22.8, a geographic information system software, to visually map the distribution of studies by location.
• Meta-Analysis and Statistical Analysis:
  • Performed in RStudio v4.4.2 using a random-effects model to account for between-study variability.
  • Subgroup analyses were conducted to understand variations by species (e.g., horses, donkeys), geographic regions, diagnostic methods used, and time periods.
  • Meta-regression was applied to explore sources of heterogeneity and temporal trends.

Key Findings

• From 57 included studies, the pooled global seroprevalence was estimated at approximately 14% (13.98%) with a 95% confidence interval of 9.45% to 19.21%.
• The prediction interval ranged widely from 0.00% to 63.90%, indicating substantial variability in seroprevalence depending on specific study conditions or locations.
• High heterogeneity was confirmed with I² = 99.4%, demonstrating that differences in study results were not due to chance but likely due to underlying factors.
• Variation in seroprevalence was observed between:
  • Equid species (different susceptibilities or exposure risks)
  • Geographic regions (regional ecological and management differences)
  • Diagnostic techniques (differences in sensitivity and specificity)
  • Time periods, with a significant decline in seroprevalence over time, possibly reflecting improved control efforts or changes in virus circulation.
• The analysis also suggested potential publication bias, meaning that studies showing certain prevalence rates might be more likely to be published, which could affect overall estimates.

Conclusions and Implications

• EVA continues to be an important global health concern for equids, with notable regional and methodological differences influencing reported prevalence.
• The study highlights the necessity for harmonized surveillance systems to monitor EVA consistently across countries and species.
• It supports the development of targeted control strategies that consider regional epidemiological differences and better diagnostic standardization.
• Findings emphasize the ongoing need for international collaboration to minimize EVA-associated reproductive losses and to facilitate safe equine trade.