Update by Food and Drug Administration signals escalation in food poisoning outbreak affecting US west and midwest

The US Food and Drug Administration said on Friday that 75 people had now been infected by the E coli outbreak linked to McDonald’s quarter pounder hamburgers, as the number sickened by the bacterial illness continues to increase.

And the Centers for Disease Control and Prevention (CDC) warned on Friday: “The true number of sick people in this outbreak is likely much higher than the number reported, and the outbreak may not be limited to the states with known illnesses.”

The update signaled an escalation of the food poisoning outbreak from the previous government report that the infections so far had killed one person, sickened 49 and hospitalized 10 across in the US. The outbreak has chiefly affected the US west and midwest after first emerging in Colorado.

On Thursday, fingers were pointed at fresh onions as the possible source of the deadly bacteria, not the burger meat as may have been expected.