A multidisciplinary team of U.S. and international scientists said finding the sources of food poisoning was more difficult because food crosses borders. Professor Jozsef Baranyi of the Institute of Food Research in Norwich, England, and colleagues used agri-food import-export data from the databases of the United Nations and Food and Agriculture Organization of the United Nations to chart out the worldwide food-transport network. A recent study by the Food Safety Authority of Ireland showed 53 countries contributed to the ingredients of an ordinary Chicken Kiev in a Dublin, Ireland, restaurant, Baranyi said. The researchers identified a number of countries as being central to the network or holding particular influence due to the dynamics of the food traffic. Stricter regulation in monitoring food trade in these key countries could benefit the network globally, the study said.