This is a fast-moving outbreak investigation. Most sick people are reporting eating Quarter Pounder hamburgers from McDonald’s and investigators are working quickly to confirm which food ingredient is contaminated. McDonald’s has pulled ingredients for these burgers, and they won’t be available for sale in some states.

McDonald's Quarter Pounder with cheese on a white background

Where sick people live

This map shows where the 49 people in this E. coli outbreak lived.

This outbreak may not be limited to the states with known illnesses, and the true number of sick people is likely much higher than the number reported. This is because many people recover without medical care and are not tested for E. coli.