An investigation has been launched after four confirmed cases of coronavirus have been linked to a food processing plant in Ebbw Vale.
Public Health Wales said workers at the Zorba Delicacies Ltd food processing plant will receive widespread, rapid testing from Tuesday.
Close contacts of the infected people have been traced.
Dr Rhianwen Stiff, PHW’s consultant in communicable disease control, said: “Investigations are ongoing as to the possible cause of the incident, and no firm conclusions can be reached at this early stage. No outbreak has been declared.
“Close contacts of confirmed cases have been contacted through the test, trace, protect process and provided with additional advice for themselves, household and other contacts.
“As a precautionary measure, and to help with further understanding of situation within workplace settings, Aneurin Bevan University Health Board, in collaboration with the Gwent Regional Test, Trace, Protect team, will carry out widespread, rapid testing of the workforce from tomorrow with the full co-operation of Zorba Delicacies Ltd.”
Dr Stiff suggested that clusters of cases could be expected in settings such as workplaces as the nation moves in to the recovery phase of the pandemic.
It follows outbreaks at food plants in Wrexham and Anglesey.