Short communication.: Can highly pathogenic avian influenza (HPAI) reach the Iberian Peninsula from Asia by means of migratory birds?

This work discusses the possibilities of direct and indirect contact across Central Asia, between migratory bird populations from the Iberian Peninsula, South western Eurasian and Eastern Asian countries. This fact should be considered when preparing surveillance studies for highly pathogenic avian influenza viruses. Records were checked from birds ringed or recovered between 1980 and 2002 in the Iberian Peninsula, an important wintering area for waterfowl in the European Union. This study only addresses migrations covering, more than 5000 km and exclusively to or from Asia. A total of seven species have developed migratory routes between Europe and the Caspian Sea/Central Asia in the following proportions to the total of birds recovered: Podiceps nigricollis (17%), Anas penelope (11.1%), A. clypeata (2.17%), A. platyrhynchos (1.86%), Pluvialis squatarola (33.33%), Calidris ferruginea (1.36%) and Sterna sandvicensis (0.67%). These recovery rates suggest the possibility of interchange - at the Central Asia and Caspian breeding grounds-between the populations originating in Europe and those from Southeast Asia. Over the following seasons, through direct migration, misorientation or, as frequently observed in certain duck species, through a phenomenon of abmigration, some birds with a priori Asian wintering quarters could conceivably escort their 'European' brethren to this continent and thus contribute to the propagation of avian flu to so far virus-free areas.