The number of coronoavirus cases linked to a food processing plant in Coupar Angus has risen to 68.
First Minister Nicola Sturgeon said 59 employees at the 2 Sisters factory had tested positive for the virus, along with nine of their contacts.
She said lockdown restrictions similar to Aberdeen's had not been imposed as there was currently "minimal evidence of community transmission in Tayside."
More than 800 workers at the plant have now been tested for the virus.
Workers and those sharing a household with them, including children, have been told they must self-isolate until 31 August.
The plant was closed on Monday for two weeks while staff at the site were tested.
Two of the contacts who tested positive have links to other food processing plants in Tayside.
Ms Sturgeon said: "The incident management team is now carrying out risk assessments at both of these sites.
"There's no evidence that this outbreak has spread to either factory at this stage, but as you can imagine, that is something that is being looked at very closely."
The factory employs than 1,200 workers when approximately 300 agency staff are included.
Ms Sturgeon said that "some people may be looking at Aberdeen and Coupar Angus" and wondering why exactly the same approach is not being taken.
She said the assessment of the incident management team in Coupar Angus "right now" is that there is "minimal evidence of community transmission in Tayside."
Ms Sturgeon added: "That's not something we were able to say with any confidence about the outbreak in Aberdeen.
"As things stand, there is a clear focal point for the Coupar Angus outbreak, which was not the case in Aberdeen where the outbreak was associated with a large number of venues across the city."
However, Ms Sturgeon said that the situation in Coupar Angus would be kept under "very close review."
Perth and Kinross Council leader Murray Lyle told Radio Scotland's Drivetime programme that there were people of 17 nationalities working at the factory.
He said it was a "challenge" for council officers to reach everyone involved.
Meanwhile a 10th person from the crew of a fishing boat in Orkney has tested positive for Covid.
NHS Orkney said the new case involves someone who does not live on Orkney, and is isolating on the mainland.
Director of public health Dr Louise Wilson revealed the new case after a meeting of the multi-agency incident management team in Orkney.
"All contacts of those involved in this cluster have now been traced but we will continue to monitor the situation," she said.