Staff at ABP Food Group's premises in Shrewsbury and Ellesmere have been confirmed as having tested positive for Covid-19.
There are eight current cases at the firm's Shrewsbury site and four suspected, and two at its Ellesmere premises.
It has also been confirmed that there have been 64 confirmed cases at the Ellesmere site since the beginning of the pandemic, with 36 of the employees who tested positive living in Shropshire.
The Shrewsbury site, at Battlefield, has had ten confirmed cases since the outbreak began – including the eight which are current.
It comes after significant coronavirus outbreaks at factories in Wrexham and Anglesey, along with cases at the Tulip meat processing factory in Tipton.
ABP's site in Battlefield, Shrewsbury, is understood to have around 700 workers.
Shropshire Council said that Public Health England (PHE) Midlands, the Health and Safety Executive (HSE) and Food Standards Agency (FSA), were all working with and ABP Food Group, following confirmation of cases of Covid-19 in the workforce.
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The council said that any affected individuals are being asked to self-isolate at home for seven days, with members of their households to isolate for 14 days.
Dr Adrian Phillips, PHE Midlands Consultant in Communicable Disease Control, said: “The management at ABP Food Group is co-operating fully with public health professionals and members of the HSE and FSA, to protect the health and wellbeing of their workforce.
“As we would expect at this stage of a pandemic, there have been cases among the workforce, as the virus is present in the local community."
Dr Phillips said that the company had taken a series of measures to protect workers, but they were now considering whether more are needed.
He said:: "The company put extensive measures in place from the start of the pandemic, and public health partners are working with the business to assess if any further measures should be implemented in the workplace and looking at the picture in the wider community.”
A spokesman from ABP Food Group said: “The health and wellbeing of our staff is of the utmost importance, so we have been keen to co-operate in whatever way possible with PHE, the council, the FSA and HSE.
“As soon as restrictions were announced by the Government, we put extensive measures in place to reduce the risk of our staff catching Covid-19, many of which went above and beyond the national guidance, including the installation of Perspex screens at workstations and provision of PPE, including visors.”
Rachel Robinson, Shropshire Council’s director of public health, said they were looking to stop the spread of cases.
She said: “The health and safety of our communities is our absolute key priority.
“We are aware of the cases of Covid-19 at ABP Foods and are working with Public Health England to support the company. A rapid response is providing vital information to help minimise the further spread of the virus in Shropshire.
“At this time, we would also like to remind everyone to follow the current Government guidance on social distancing, minimising their social interaction with other people, maintaining good hand hygiene by washing hands regularly for at least 20 seconds, and covering mouth and nose with a tissue when coughing or sneezing. Adhering to this advice is the best protection against the virus. Please stay safe, be responsible and together we can reduce the spread of this coronavirus.”