NHS Tayside has confirmed there are 29 cases of coronavirus associated with a chicken factory in Coupar Angus.
The 2 Sisters food processing plant closed earlier this week after staff members tested positive for the virus.
First Minister Nicola Sturgeon previously reported on Wednesday at the Scottish Governments daily briefing that 17 cases had been linked to the factory.
Health board bosses have confirmed that those with cases have mild symptoms and are isolating at home.
Mobile testing units are on site at the factory and will remain there until the end of the week.
All workers are advised to attend for a test even if they don’t have symptoms and the factory is communicating with staff members to inform them how they can access the testing.
All staff have been told they must self-isolate for 14 days and stay home until August 31, two weeks from the closure of the factory.
If a worker develops symptoms after testing negative they must get retested.
Dr Emma Fletcher, Associate Director of Public Health for NHS Tayside, encouraged staff from the factory to take up the offer of a coronavirus test.
She said: “All agencies continue to work closely together to manage the outbreak related to the factory.
“We strongly encourage all workers to take up the offer of testing to help prevent further spread of the infection in the community.
“The public should be reassured that the plant remains non-operational however contractors are continuing to attend the site to ensure animal welfare.
“Children of factory workers who are self-isolating can continue to attend school as long as they have no symptoms and have not tested positive.
“Our advice to the wider community is to remain vigilant to this infection. Please continue to follow the FACTS guidance and if anyone is experiencing symptoms of coronavirus, they should self-isolate and seek a test.”
To book a test visit the NHS Inform website.