The McDonald's E. coli outbreak tied to Quarter Pounders has sickened 75 across 13 states, prompting health agencies to investigate slivered onions as a likely source. With 22 hospitalizations and one reported death, McDonald's ceased sourcing onions from a Colorado facility. Regulatory bodies continue to analyze the situation, while other fast-food chains withdraw potentially contaminated onions. Despite escalating cases, McDonald's minimizes menu changes, stating some illnesses may arise from travel. Litigation against McDonald's has begun, as experts caution that the outbreak underscores broader produce safety issues. Analysts express concern about potential impacts on customer trust and sales.