7. Border Inspection and Trade Diversion: Risk Reduction vs. Risk Substitution

International trade increasingly brings previously separated geographical regions into contact with one another and increases the frequency of those contacts. These trends bring many benefits to the trading partners involved, but increasing international trade also facilitates the spread of pathogens and increases disease risks. The rapid growth of trade, transport, and travel across national borders has increased the frequency of introduction, establishment, and spread of invasive infectious pathogens (Jones et al. 2008). The development of new trade pathways and the growth in the number and volume of commodities traded increase the likelihood that novel infectious pathogens are introduced to importing or stop-over countries. The growth in trade volumes has increased the risk that introduced pathogens establish and spread, because it has increased the frequency with which infectious pathogens are introduced (Cassey et al. 2004; Dalmazzone 2000; Semmens et al. 2004). Other factors such as the bioclimatic similarities between trading partners, the vulnerability of ecosystems in the importing countries, and risk management policies adopted by both importing and exporting countries also influence the risks of invasive infectious pathogens (Wiens and Graham 2005).