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Health bosses in Bristol and South Gloucestershire say they're confident an outbreak of a mutation of Covid-19 is improving.
Surge testing started in parts of Bristol and South Gloucestershire last week.
So far 33,000 people have been tested, with only one per cent of those being positive.
It is not yet known if any of those people have the Bristol variant of the virus.
Director of Public Health in Bristol Christina Gray said there has not been a large number of cases of the Bristol variant found in old test results, so it does not appear there is a "reservoir" of asymptomatic positive people.
She said: "All the enquiries are finding a few more cases, that's a good thing because it means they can be followed up and isolated, but we've not seen a large number of cases from the asymptomatic testing and we're not seeing a large number of the new variant appearing from the public health investigations."
But she said it is a "changing picture" and we need to "wait and see" how it plays out.
She stressed the picture at the moment is "reassuring", as there is no indication of a large amount of "background infection" in the city.
How to get a coronavirus surge test
People living in certain BS postcodes can get a test as part of the additional testing programme if they do not have symptoms and are over the age of 16.
Health services say around 10,000 coronavirus tests issued as part of surge testing have not yet been returned.
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