A thousand staff working at a turkey processing plant will be tested for Covid-19 as part of ongoing measures to prevent the spread of the virus.
The tests will take place at Bernard Matthews in Holton, Suffolk.
It comes after 72 staff members tested positive for Covid-19, with 13 currently self-isolating.
Suffolk's director of public health, Stuart Keeble, said: "Testing all staff now is a sensible, precautionary and preventative measure."
Swabbing of the 1,000 workers will be carried out and samples sent to the Norfolk and Norwich University Hospital.
Health officials hope this will identify asymptomatic staff who are currently showing no signs of Covid-19.
Staff who test positive will be required to self-isolate at home.
Public Health Suffolk said food production and safety would be unaffected.
Other measures already introduced since the first cases were identified last month include the introduction of new entrances to aid one-way movement of staff, breaks being staggered and the introduction of bus marshals on the firm's free staff transport.
Mr Keeble said Public Health Suffolk was working closely with the turkey processing giant to "stop the spread of Covid-19, identify those affected and therefore protect staff and the public".
Consultant in health protection at Public Health England East, Rebecca Hams, said testing and tracing was key to "identifying and containing the spread of Covid-19" and "staff at the factory are being tested as a precautionary measure".
She said: "Mass testing in this way, will help protect staff and the community, by allowing us to identify people who are carrying the virus, but who have not developed symptoms."