A further 16 people have tested positive for coronavirus at Banham Poultry, bringing the total number of cases to 96.
In an update on Monday, Dr Louise Smith, director of public health, said the factory had been deep cleaned and mobile testing units were on site to carry out testing.
To date, 477 members of staff out of 800 have been tested, with more results due back in the coming days.
The company is also bringing in a new group of 45 people to staff its slaughter house.
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A number of people are believed to have reported to the James Paget University Hospital, in Gorleston, of which a “very small number” of people have attended for treatment.
She stressed that at this stage there was no need for a local lockdown in the area.
Dr Smith said: “Clearly the numbers of cases in this outbreak are rising and there are a number of different elements of response and work that we are working on including ensuring animal welfare, the support for the business as well as the public health imperative to interrupt and reduce the spread of coronavirus.
“It remains the case we do not have evidence of spread in the wider community. We are linking the cases back to this outbreak and we do not believe we do not need to move towards a wider lockdown at this stage.”
Earlier on Monday afternoon, George Freeman, MP for Mid Norfolk, said a more urgent response is needed to prevent a “potentially catastrophic” impact on the county’s food industry in the wake of the Banham Poultry coronavirus outbreak.
In response, Dr Smith said: “Like Mr Freeman we have been concerned to ensure that the regional and national NHS test and trace have been as comprehensive and as rapid as possible.
“We have been seeking information about how effective the contact tracing has been. We have been assured it has been operating over the weekend and significant number of contacts have been processed through the tiers of the national services structure.
“My priority as director of public health is to ensure that the public health both of the staff at the site and working across the county is protected as much as possible.
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“But clearly there are other issues to balance in that risk assessment, not least the best and most humane way to manage the livestock that has been weighed into the balance of the risk assessment as well.”
Anyone who has tested positive must isolate for 10 days from the day of receiving a positive test result, or isolate for 14 days if they have worked closely with someone who has tested positive.
Steve Morphew, leader of the opposition Labour group at County Hall, said: “This is a stark reminder of how easy it would be for the virus to spread unless we all stick to the rules and the lessons from the first wave are learned and acted on.
“With schools and colleges returning in Norfolk this month I’d rather see us do too much too soon than too little too late.”
Anyone who needs help self-isolating can contact the Norfolk Assistance Scheme on 01603 22 3392. The line is open 10am and 4pm Saturday, Sunday and Bank Holiday Monday.
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