Most Salmonella infections are caused by eating contaminated food. One study found that 87% of all confirmed cases of Salmonella are foodborne. Foods of animal origin, including meat, poultry, eggs, or dairy products can become contaminated with Salmonella. Eating uncooked or inadequately cooked food—or food cross contaminated with uncooked or undercooked products—can lead to human infections. As explained in a comprehensive report issued by the U.S. Department of Agriculture’s Economic Research Service:
Salmonella contamination occurs in a wide range of animal and plant products. Poultry products and eggs are frequently contaminated with S. Enteritidis, while beef products are commonly contaminated with S. Typhimurium. Other food sources of Salmonella may include raw milk or other dairy products and pork.