Identification of Hotspots in the European Union for the Introduction of Four Zoonotic Arboviroses by Live Animal Trade

Abstract

Live animal trade is considered a major mode of introduction of viruses from enzootic foci into disease-free areas. Due to societal and behavioural changes, some wild animal species may nowadays be considered as pet species. The species diversity of animals involved in international trade is thus increasing. This could benefit pathogens that have a broad host range such as arboviruses. The objective of this study was to analyze the risk posed by live animal imports for the introduction, in the European Union (EU), of four arboviruses that affect human and horses: Eastern and Western equine encephalomyelitis, Venezuelan equine encephalitis and Japanese encephalitis. Importation data for a five-years period (2005-2009, extracted from the EU TRACES database), environmental data (used as a proxy for the presence of vectors) and horses and human population density data (impacting the occurrence of clinical cases) were combined to derive spatially explicit risk indicators for virus introduction and for the potential consequences of such introductions. Results showed the existence of hotspots where the introduction risk was the highest in Belgium, in the Netherlands and in the north of Italy. This risk was higher for Eastern equine encephalomyelitis (EEE) than for the three other diseases. It was mainly attributed to exotic pet species such as rodents, reptiles or cage birds, imported in small-sized containments from a wide variety of geographic origins. The increasing species and origin diversity of these animals may have in the future a strong impact on the risk of introduction of arboviruses in the EU.

Climate change impacts on West Nile virus transmission in a global context

“…All of these factors and others play an important role in the worldwide dispersion of the pathogen and vector [23,114].…”

Application of a quantitative entry assessment model to compare the relative risk of incursion of zoonotic bat-borne viruses into European Union Member States

“…Thus, the main strengths of this model lie in the comparison of the relative risks between viruses and routes of entry. Whilst there have been several risk assessments carried out for the introduction of individual pathogens into the EU (Rolin et al, 2013;Durand et al, 2013;Mur et al, 2014;Snary et al, 2012) this model was able to assess a range of viruses and could be adapted for other pathogens, as it has the advantage of easy access to a number of relevant databases. The model also allows for a continual updating of the risk estimate enabling the stakeholder to respond in a rapid and risk appropriate manner, for example, by implementing risk-based surveillance and control strategies.…”

The challenges posed by equine arboviruses

“…For example, a study to identify hotspots for potential introduction of EEEV, WEEV, VEEV and JEV to Europe through live animal trade demonstrated that the risk was higher for EEEV than the other three viruses, which was mainly associated with trade in exotic pet species such as rodents, reptiles or caged birds [2]. For example, a study to identify hotspots for potential introduction of EEEV, WEEV, VEEV and JEV to Europe through live animal trade demonstrated that the risk was higher for EEEV than the other three viruses, which was mainly associated with trade in exotic pet species such as rodents, reptiles or caged birds [2].…”

“…These include increased movement of animals and people worldwide, environmental and climate change, and human encroachment into natural habitats (taking domestic species with them). Equine arboviruses are no exception to this trend, and a number of authors have highlighted the potential for the introduction of various equine arboviruses to Europe [2][3][4].…”