Alberta health officials have confirmed an outbreak of norovirus at a retirement home in Okotoks, Alta.

Nine people are sick at The Heartland Retirement Residence.

Alberta Health Services (AHS) says those individuals have been isolated and there is enhanced cleaning of frequently-touched surfaces.

Norovirus — once known as Norwalk virus — is highly contagious and often spreads in places like schools, cruise ships and nursing homes, especially during the winter.

The stomach bug causes bouts of vomiting and diarrhea which can last for a few days.

A new strain of the virus evolves every two or three years.