Seventy-five at a Bernard Matthews plant in Norfolk tested positive for coronavirus.
The Norfolk County Council on Thursday showed the number of cases at the Great Witchingham turkey plant, where precautions have been taken since last week.
600 workers were tested on site, with 75 positive effects, most of which were shown in other people who had worked in the afternoon quarter.
As a result, Public Health England ordered self-de-iaising.
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In a statement, the board said: “Staff are asked to isolate themselves for 14 days if they have tested positive or tested them.
“Staff will need to be isolated for 10 days if they have a positive test result, and families with positive cases, in addition to children, should be isolated for 14 days. “
News of the outbreak comes after Bernard Matthews plant in Suffolk reported a similar wave of cases last week.
Another seventy-two people tested positive at the Holton food processing plant near Halesworth, according to the Suffolk County Council.
This led the company to introduce bus marshals into its free shipment to respond to the outbreak.