The Sudbury and District Health Unit says it's had an increase of reports of Norovirus after it's received calls from the community, daycares, long-term care homes and schools.
The virus — commonly known at the stomach flu — is different than influenza, for which people can get vaccinated, said a health unit spokesperson.
"Norovirus has no vaccine, there's no antibiotics people can take," Cindy Rocca said.
"What we recommend here at the health unit that if you are suffering from the symptoms — and it is Norovirus — to remain hydrated as best as possible and drink a lot of fluids."
Rocca says Norovirus is still contagious after the symptoms stop and that it's best to wait 48 hours before returning to work or school if one has been sick.
Norovirus makes people sick to their stomach, while the influenza targets the respiratory system.
The health unit suggests hand washing and sanitizing common surfaces to avoid further spread of the virus.