Satellite data reveals a very small window of 5 to 15 days for bird flu virus to spread distances over 500Km.
Research published in British Ecological Society’s Journal of Applied Ecology reveals why the global spread of bird flu by direct migration of wildfowl is unlikely but also provides a new framework for quantifying the risk of avian-borne diseases.
Dr Gaidet’s team analysed 228 birds from 19 species using satellite telemetry from 2006 to 2009 over the bird flu affected areas of Asia, Europe and Africa. The results indicated that migrating wildfowl do have the potential to disperse H5N1 over extensive distances as mass migration can result in infected birds covering as much as 2900km before symptoms become apparent.
However, while this is theoretically possible the team found that direct virus dispersal by migrating birds would require asymptomatic infection to coincide precisely with the migration season. The results revealed a very small ‘window’ of between 5 to 15 days when dispersal of the virus over 500 km could occur.