The South Bruce Grey Health Centre says the inpatient unit at the Chesley hospital is currently experiencing an outbreak of respiratory illness.
The infection was first reported on Monday.
There is currently a limit of one visit per patient, but otherwise visitation is not restricted.
However, the SBGHC asks that people do not visit if they are ill and that they check in with the Nursing Staff when arriving on a unit.
The infectious agent has not been identified yet by Grey Bruce Public Health, but you can track all the respiratory outbreaks in the region by visiting their website.