Leading cause of food-borne illnesses is a virus, mostly from restaurant workers who fail to wash hands, CDC finds. Salmonella bacteria was second. Among 17 individual food types, poultry was most common source of illness. Dairy products accounted for 3 percent of outbreaks, most from unpasteurized milk. And: In 2008, chicken sales increased 6.7 percent - three times overall growth rate for retail, food service meat (click 'See also').