Around 140 people have tested positive for coronavirus at a Norfolk meat processing factory, it has emerged today.
Norfolk County Council said there had been a 'significant outbreak' of Covid-19 at the Cranswick Country Foods site in Watton.
Some 300 members of staff at the factory have been tested so far, with the remaining employees due to be swabbed today.
The outbreak comes as 75 workers at a Bernard Matthews turkey plant in Great Witchingham, Norfolk, also tested positive for coronavirus earlier this month.
There has been a 'significant outbreak' of Covid-19 at the Cranswick Country Foods site in Watton (pictured)
The council's director of public health, Dr Louise Smith, said the local authority was working with the Joint Biosecurity Centre to urge people in the Watton area to get tested if they have symptoms.
She said in a statement: 'Testing of staff at Cranswick Foods has revealed a significant outbreak.
'At this stage we have identified about 140 positive cases out of around 300 tested so far. The analysis of swabs continues and the remaining staff on site are being tested today and tomorrow.
'Due to the high proportion of positive case results received so far, we are liaising with the Joint Biosecurity Centre and have stepped up contact tracing and leafletting in the Watton area, urging people with symptoms to access testing.'
Cranswick Country Foods has been contacted for comment.
As of October 15 there had also been 72 positive cases at Bernard Matthews' food processing facility in Holton near Halesworth
Some 75 workers also tested positive at a Bernard Matthews turkey plant in Great Witchingham, Norfolk
Chilled and damp interior with ultraviolet light: Why meat plants are a hotbed for coronavirus outbreaks
The virus thrives in cold, damp and indoor environments, particularly on cool surfaces.
The lack of a breeze or ultraviolet light from the sun means the moisture remains and can't be killed off inside food processing plants.
Furthermore, social distancing is particularly difficult in workplaces with a busy production line meaning the virus is likely to spread more easily.
Loud machinery also forces people to raise their voices and researchers say situations where people have to shout result in an increased risk of projecting the virus to others.
It's not just in the UK where a trend has been seen, either, after hundreds tested positive in a Berlin slaughterhouse, while a wet market in Wuhan is believed to have been at the heart of a huge number of infections early on in the crisis.
The local authority said testing at the Bernard Matthews turkey plant began on October 15, with more than 600 members of staff tested.
'Results showed that the majority of positive cases so far worked on the afternoon shift at the site, leading Public Health to advise Bernard Matthews that the entire shift be instructed to self-isolate,' Norfolk County Council said.
As of October 15 there had also been 72 positive cases at Bernard Matthews' food processing facility in Holton near Halesworth, Suffolk County Council said.
In Suffolk, Bernard Matthews brought in Covid-19 bus marshals on its free staff transport as part of its response to the outbreak.
Food production at the processing facility has not been affected by the Covid outbreak.
The site has had controls in place since March to reduce coronavirus infections, including regular temperature checks, staff working in bubbles, Covid marshals, masks and visors and social distancing.
The majority of the 18 workers who tested positive live in the Great Yarmouth and Lowestoft areas and the cases are believed to have been caught in the community.
Officials including from Suffolk County Council, Public Health England and Bernard Matthews are working together to manage the situation.
Earlier this month ten cases were linked to a Scunthorpe factory where employees claimed they were told not to wear masks because they are food hazards.
The Karro Food Group pork processing plant, one of the country's largest food producers, was criticised by employees for its coronavirus measures.
Workers reported a spate of cases over the last week, though the company claimed they were infected through 'community contact'. It also insisted it was following all government guidelines.
One employee at the factory, who wished to remain anonymous, said: 'Staff are dropping like flies and being sent home. There's around ten confirmed cases now.'
Food factories ravaged by Covid outbreaks
- October 26: Cranswick Country Foods site in Watton, Norfolk
- October 22: Bernard Matthews turkey plant, Great Witchingham, Norfolk
- October 6: Karro Food Group pork processing plant in Scunthorpe
- September 30: Pilgrim's Pride food factory in Pool, near Redruth, Cornwall
- September 29: Bernard Matthews turkey plant, Holton, near Halesworth in Suffolk
- September 23: Greggs factory in Newcastle
- September 11: Aunt Bessie's Yorkshire pudding factory in Hull
- September 2: Millers of Speyside in Scottish Highlands
- August 26: Food Standard's Authority reveal there are at least 40 active outbreaks at factories in the UK
- August 22: Banham Poultry in Attleborough, Norfolk
- August 21: Greencore in Northampton
- August 20: Cranswick in Ballymena, Northern Ireland
- August 18: Bakkavor in Newark
- August 17: 2 Sisters Food Group in Coupar Angus, Tayside
- August 17: Fyffes in Coventry, West Midlands
- August 13: Greencore in Northampton
- July 12: AS Green and Co, Herefordshire
- July 3: Walkers, Leicester
- June 26: Tulip, Tipton
- June 24: Kepak Food Group in Merthyr Tydfil, Wales
- June 23: Princes, Wisebech
- June 19: Asda, Cleckheaton, West Yorkshire
- June 19: Rowan Foods in Wrexham, Wales
- June 17: 2 Sisters food factory in Anglesey, North Wales
- May 15: Cranswick, Barnsley
- May 11: Moy Park in Dungannon, Northern Ireland