Lambton Public Health says there has been a spike in the number of flu cases locally.
Supervisor Erin Courtney says there have been 31 confirmed cases of the flu in Sarnia-Lambton, compared with zero at this time last season.
She says there has also been one long-term care home outbreak.
Infants, seniors and individuals with a chronic health condition are considered to be at most risk from the flu.
Residents are also reminded to continue to prevent spread of the viruses by washing hands with soap frequently, keeping ill family members home from school or work and cleaning regularly touched surfaces like door handles and computer keyboards often.
There were 79 confirmed cases of the flu in Sarnia-Lambton last season and one flu related death.
