McDonald’s said Wednesday that customers should feel confident ordering from its restaurants despite a deadly E. coli outbreak linked to its Quarter Pounder hamburgers.

McDonald’s said it was taking “swift and decisive action” to control the outbreak that has sickened dozens of people, mainly in Colorado and Nebraska.

Health officials linked an E. coli outbreak to McDonald's Quarter Pounders. The Centers for Disease Control and Prevention has launched an investigation to determine which ingredients are contaminated.