The outbreak at the Greater Niagara General Hospital is spreading.
At least 21 patients and staff across three units are now infected with COVID-19.
Niagara Health says Trillium, Rainbow and Unit D are all impacted.
A staff member in one unit tested positive for the virus on Friday, prompting Niagara Health to declare the first outbreak.
A second outbreak was called on Saturday, after another staff member in a different unit tested positive.
Efforts are underway to control the spread and contain the virus.

Kristen French Centre Battling Online Luring
Niagara's Crime Severity Rate Drops
Man Dies in Niagara Falls Motorcycle Crash
2nd Niagara Falls Murder Suspect Arrested
Suspect Wanted After Cables Cut
Candidates Splurge on Election Signs
Homeless, City Finances Top Candidate's Concerns
Police Investigation Resolved