Nova Scotia's Department of Health says just two people who were infected with E. coli O157 remain in hospital Tuesday.
Ten cases have been reported in the province so far, with another five in New Brunswick.
Health officials believe the source is produce served at restaurants, but they haven't been able to pinpoint which produce.
"Food safety specialists have been visiting all the places where the people who have been infected by this outbreak have eaten," said Dr. Fran Atherton, deputy chief medical officer of health for Nova Scotia. "They're looking at that and the good news is we haven't seen any breaches of hygene protocol in those food outlets."
Officials said there has been an increase in the number of people contacting their doctors, worried they might have been infected. But the majority of those cases are Norovirus, an infection that causes sudden nausea and vomiting.
The symptoms of E. coli tend to last several days, where Norovirus can pass within 24 hours.