Serosurveillance of orbiviruses in wild cervids from Spain (Letter)

In recent years, several emerging vectorborne diseases, including bluetongue (BTV-1, BTV-4 and BTV-8), Bagaza, Schmallenberg, Usutu and West Nile, have been reported in southern Spain, most of them originating from north Africa. Although EHDV circulation has been recently detected in livestock in the Mediterranean basin (EHDV-6 in Morocco, Algeria, Tunisia and Turkey during the period 2006-2008; EHDV-7 in Israel during 2006), no outbreaks have been reported in Europe. However, the presence of competent vectors for EHDV, the high density of wild and domestic ruminant species and the geographical proximity to north Africa, suggest that Andalusia (southern Spain) can be considered a potential risk area for the introduction of arboviruses, including EHDV. Our results suggest that EHDV has not circulated in Andalusia during the period 2006 to 2012. BTV has circulated in wild cervid populations from Andalusia in the past two years. Serological results indicate an absence of cross-reaction between EHDV and BTV in the ELISA used in the present study. EHDV in north Africa poses a major risk for European countries because of likely windborne dispersal of infected vectors. Therefore, permanent monitoring for EHDV, including active and passive surveillance in wild and domestic ruminant species and entomological surveillance, should be implemented in Andalusia.