Shropshire Council said there have been 21 cases in the county linked to the outbreak at Cake Crew in Bala.
The cases have been identified in the Oswestry and Ellesmere area.
Rachel Robinson, Shropshire Council’s director of public health, said that it is still likely the number of people infected will increase.
She said: "There are now 21 cases in Shropshire linked to the outbreak in Wales and we do expect that there will be more cases as the programme of screening and testing continues.
“The people who have tested positive and their contacts will isolate for 10 days.
“We’re working with the community and the factory to promote regular testing, as well as the other measures like ‘hands, face, space’, and taking up the vaccination offer when it becomes available.”
Rapid Covid tests have been available to residents in both Ellesmere and Oswestry.
For information about sites, visit the Shropshire Council website.