Guelph General Hospital says C. difficile may have contributed to the death of an elderly patient Thursday, who contracted the illness in June while in hospital.
Two other patient deaths have been linked to the bacterial outbreak, including one earlier this week.
No new cases have been reported in Guelph since Monday, but nine patients remain ill.
C. difficile has been linked to at least 23 deaths in Ontario hospitals since May.
Outbreaks are still being dealt with at five other Ontario hospitals, including in one in Orangeville and four in the Niagara Region.
The outbreak at a Mississauga hospital ended Thursday, though some patients may still be ill.
Guelph General Hospital says increased infection control efforts are continuing, including more cleaning and greeters to provide information on the outbreak and proper hand cleaning.
According to a press release, some elective surgeries may be cancelled in the next few weeks to keep private rooms available to help those with the illness recover.
An outbreak can be declared over when there are no new hospital-acquired cases for 30 days.
With files from The Canadian Press.
