Equine disease events resulting from international horse movements: Systematic review and lessons learned

Abstract

SummaryReasons for performing study: An analysis of the factors leading to equine disease events was used to support the development of international recommendations for mitigating the risk of disease dissemination through sport horse movements (high health, high performance -'HHP' horses). Objectives: A review was undertaken to identify the factors resulting in equine disease events following international movement of horses to draw lessons in support of the development of international recommendations for the safe movements of a specific subpopulation of horses: the HHP sport horses. Study design: Systematic review carried out in accordance with the PRISMA statement. Methods: The review covered disease events that occurred from 1995 to 2014, identified from the databases of the World Organisation for Animal Health (OIE) and international surveillance reports. Results: Overall, 54 disease events were identified, of which 7 were contained in post arrival quarantine and the others resulted in the introduction of pathogens into importing countries. For 81% of the introductions, the OIE recommendations applicable to the diseases involved had not been complied with. Subclinical infections are a challenge for international trade: 88% of the regulated movements that resulted in introductions involved infected horses that showed no clinical signs at the time of import. Biosecurity and management practices in resident equine populations were identified as important mitigating factors in preventing disease spread to the local horse population. Conclusions: The global increase in international horse movements, if not appropriately regulated and supervised by competent veterinary authorities and respective equine industry partners, could potentially lead to increased global spread of infectious equine diseases. Appropriate mitigation measures and compliance with OIE import recommendations for specific diseases can significantly reduce this risk. The recommendations proposed under the HHP approach take into account the mitigation measures identified by this review as important factors in preventing pathogen introduction and spread.

Reemergence of H3N8 Equine Influenza A virus in Chile, 2018

“…Horses arrived individually or in groups of less than 12 animals, representing 167 entries total and most of them were Thoroughbred horses. Therefore, this virus was likely introduced by imported horses, similar to previous equine IAV introductions in the region (Dominguez et al., ; Perglione et al., ).…”

“…Although, the equine IAV that caused the Chilean 2018 outbreak is also within the FC1 clade, the inferred phylogenetic relationship with reference sequences indicates that this event corresponds to a new introduction, related to concurrent outbreaks occurring globally in Europe, Asia, and North America. Equine influenza is mostly spread between countries as a consequence of international horse movements (Dominguez, Münstermann, de Guindos, & Timoney, ), which explains the circulation of highly similar strains in Chile, the UK, and Japan. In Chile during 2017, 447 horses were imported from 13 different countries, including the United States (40%), Argentina (33%), France (11%), and others (16%).…”

Phylogeography of equine infectious anemia virus

“…However, during the last decade, we observed some irregular trends in the genetic diversity of the virus, as a result of numerous outbreaks occurred worldwide, causing dramatic economic consequences (Timoney, 2000; Cook et al, 2013; Herholz et al, 2013). These epidemic pattern has been facilitated by the continuously growing international horse trade (Metcalf, 2001, Dominguez et al, 2015).…”

How to critically appraise a paper

“…In addition, there are many sources of nonpeer-reviewed literature, including textbooks, reports and proceedings and the internet. Formal systematic reviews are beginning to appear in the equine veterinary literature (Allen et al 2012;Sullivan et al 2015;Dominguez et al 2016), and RCVS Knowledge and the Equine Veterinary Education are beginning to publish knowledge summaries (or critically appraised topics) (RCVS Knowledge 2017). However, it is usually up to the individual reader to assess the scientific validity, strength of evidence and practical relevance of results presented in a paper and the extent to which they can be applied to the particular question they are interested in.…”