ATLANTA, GA (MyBellinghamNow.com) – The fast-moving E. coli outbreak tied to McDonald’s Quarter Pounders has made its way to Washington.

The CDC announced on Friday, Oct. 25, that at least one state resident had become ill from the contamination. The agency later clarified that the resident’s illness was not linked to a McDonald’s in Washington and that they were likely exposed at a location outside of the state.

Early reports from the CDC indicate that onions may have caused the outbreak, though the cause is still under investigation.

McDonald’s says that California-based onion supplier Taylor Farms issued a recall for possible E. coli contamination and the fast food chain has pulled the Quarter Pounder from menus in several states.

Other national fast-food chains have temporarily stopped using fresh onions including Taco Bell, Pizza Hut and KFC.

So far, 75 people across 13 states have been reported ill since Tuesday, including one death from an older adult in Colorado.

The CDC adds that the total number of afflictions is likely an underestimate because many people recover without treating it and are not tested.