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The Centers for Disease Control and Prevention has increased the number of people who’ve contacted E. coli in an outbreak linked to romaine lettuce from coastal counties in California.

As of Dec. 6, according to the federal agency, 52 people in the U.S. have been infected with E. coli o157:H7, with illness onsets from Oct. 5 to Nov. 18. When the outbreak was first reported, those cases were limited to about a two-week period from mid-October to early November.

The Public Health Agency of Canada on Dec. 6 also increased the number of people who have been sickened in the outbreak, to 29. According to that agency, people reported eating romaine at home, in prepared salads from grocery stores, or from restaurants, including fast food chains.

In the U.S., individuals reported eating different types of romaine at several restaurants and at home.

U.S. retailers are re-stocking romaine supplies following the FDA’s Nov. 20 decision to remove the lettuce to provide a clear break from production in six California counties suspected of being the origin of the lettuce.

In Canada, retailers and suppliers are “working to bring romaine lettuce into the Canadian marketplace” from regions the FDA has deemed safe, according to the Public Health Agency of Canada’s Nov. 6 update.