Public health officials are investigating an outbreak at a mushroom farm in Vaughan, Ont. after 30 workers tested positive for COVID-19.

York Region Public Health (YRPH) said they were first notified of a confirmed case of the disease at Ravine Mushroom Farm, located near King Vaughan and Weston roads, on June 27.

At least 24 of the 30 patients were residents of York Region, officials said.

“YRPH conducted risk assessments on the activities of these individuals while at work and determined the risk of COVID-19 transmission to the general public is low,” York Region Public Health said in a statement.

Officials said they are following up with close contacts of the confirmed cases and have conducted a follow-up inspection of the facility, “reaffirming the importance of employees not working while ill.”

In a video statement, York Region’s Medical Officer of Health Dr. Karim Kurji said on Monday that public health inspectors have provided advice to farmers on infection prevention and control, and have ensured that “the living conditions are adequate.”

In a statement, Ravine Mushroom Farm said it is working to care for the affected farmers.

"We’re taking care of our employees at the moment and that is our priority," General Manager Peter Quattrociocchi said.

"We are continuing to work closely with York Region Public Health."

The majority of COVID-19 cases in Ontario have been reported in the Greater Toronto Area, including York Region and Peel Region.