Transboundary spread of pig diseases: the role of international trade and travel

Beltran-Alcrudo, Daniel; Falco, John R.; Raizman, Eran; Dietze, Klaas

Fomites are materials that can carry infection and can include vehicles, clothing, footwear, feed, or even vaccines. Insufficiently cleaned and disinfected empty livestock trucks that have been contaminated from transporting infected pigs have been recognized as an important route of disease transmission for pig diseases [30, 54] . Vehicles transporting pigs to farms, markets or slaughterhouses, delivering feed, or collecting carcasses represent a great risk for disease transmission [10] . Numerous studies have focused on the role of contaminated vehicles. The CSF introduction into the Netherlands in 1997 was traced to a transport truck that had been in contact with infected pigs or infectious material in Germany [37] . Afterwards within the same European epidemic, such trucks became the most important disease transmission route during the epidemic in the Netherlands [37, 107] . Also the 1997 primary CSF outbreak in Belgium was attributed to a transportation lorry from the Netherlands [37] . Canada suspected infected feeds and trucks coming from the US as the most likely way by which PED virus entered the country [87] . Contaminated vehicles from China have also been considered to be responsible for the PanAsia FMD strain outbreaks in pigs in Siberia in April 2000 [47] . This pathway has been further analyzed through risk assessments for CSF introduction into Denmark [17] , as well as ASF [75] .