Caroline Smith DeWaal, food safety director at the Center for Science in the Public Interest, said better food safety practices since the adoption of Hazard Analysis and Critical Control Points programs in the meat, poultry and seafood industries might have contributed to the decline.
However, incomplete reporting of outbreaks by understaffed and financially stretched public health agencies might also influence the data, DeWaal said.
"Despite progress made by the industry and by food safety regulators, contaminated food is still causing too many illnesses, visits to the emergency room and deaths," DeWaal said in a statement. "Yet state and local health departments and federal food safety programs always seem to be on the chopping block.
"Those financial pressures not only threaten the progress we've made on food safety, but threaten our very understanding of which foods and which pathogens are making people sick."
Produce, responsible for more food-borne illnesses than any other category of food, remained relatively flat over the study period, but illness related to dairy reached their highest point in 2010, perhaps due to the increased availability of raw, unpasteurized milk and cheese, which should not be consumed, the organization said.