GM Mayor says it is important not to over-react to Covid-19 case numbers
At his weekly press conference Andy Burnham suggested extra testing in schools might have played a role in the most recent figures.
Wigan saw a decrease from 97.4 cases per 100,000 residents in the week ending March 5 to 95.8 per 100,000 people in the week up to March 12.
However, across Greater Manchester seven of the 10 local authorities showed an increase.
For the latest week of figures Wigan was just below the city-region's average of 96.5 cases per 100,000 residents.
Mr Burnham said the current situation was a concern, but it was important not to panic.
He said: "It's a changed picture, but one we predicted. It was described to us as 'a bumpy picture', so we will be watching out for those bumps as we go further forward.
"It's important not to over-react. This is the first rise after a sustained period of reduction and we do believe the testing regime in schools might partly explain the change we've seen.
"Next week there will be more home-based testing next week and we will have to see what that does to the number of tests taken and the case numbers.
"It is a case of keeping a watching brief."
Mr Burnham said it was also important for people to remain vigilant against Covid, especially with new variants of the virus being found within Greater Manchester and across the country.
He backed the Government's move to allow businesses to have lateral flow testing and urged companies in the city-region to take up the offer.
He also once again questioned the adequacy of the arrangements in place for supporting people who need to self-isolate after testing positive.
He said: "This remains a chink in our armour that Covid might be able to exploit. It's very important that when we are doing testing in schools, as we are, and testing in businesses as we will soon be doing.
"We still believe the Government hasn't done enough on this question and will continue to make the case."
Mr Burnham backed a new campaign by business leaders and key organisations to ensure employers do the right thing when employees have to self-isolate.
The statistics showed there has been a significant increase in testing done due to the schools going back, with Pillar 2 tests in Wigan rising from 7,008 in the week up to March 6 to 13,830 in the week up to March 13.
The heatmaps showed the highest case numbers are being found among the working-age population.
Mr Burnham said the situation in the city-region's hospitals was "higher than we would like but stable" and reported NHS staff had told him the health service was now in a position it had last been in during October 2020.
Mr Burnham also celebrated the achievement of the 1,000,000th vaccine dose being given out in Greater Manchester. The stats showed some 92 per cent of over-70s have now had their first jab.
The mayor said second doses were about to begin for those who got their initial jabs back in January and it was important they look at when they booked appointments or be aware they may receive a reminder by text or phone call.
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