CONCERNS are growing about the rising rate of the Delta variant in Northern Ireland with positive cases more than doubling in one week.
Figures last week revealed there had been 111 probable or confirmed cases detected.
But statistics yesterday showed the number had risen sharply to 254.
It comes amid fears that the next two weeks are crucial in trying to stop the spread of the new variant, which is believed to be up to 60 per cent more transmissible than the Kent variant.
Enhanced testing also began in Ballymoney and Omagh yesterday after several "probable cases" of the Delta variant were identified.
Households are being contacted by post by the Public Health Agency (PHA) regarding testing after "two different distinct clusters of cases".
It is hoped testing will help find cases in which people are showing no symptoms.
Dr Brid Farrell from the PHA said: "We encourage all those eligible in the neighbourhoods identified by the agency to present for testing, preferably within 24-72 hours of receiving their letter.
"We are particularly interested in people in the 18 to 40 age group coming forward for testing as we are seeing more cases of the Delta variant in this age group throughout Northern Ireland."
A similar voluntary testing exercise took place in Kilkeel earlier this month, when a small number of probable Delta variant cases were found.
The alarm in the increase in cases saw executive ministers stall plans for a further relaxation in coronavirus measures.
On Thursday, the executive said it had decided to push back the easing of proposed Covid-19 rules until next month due to the rapid increase of the Delta variant.
It had been hoped 10 people from two households would have been able to meet indoors and live music permitted at venues that sell food and drink.
But the executive said it was concerned by the "continued advancement of the Delta variant which has become more prevalent in the last seven days".
"This increase in the Delta variant, and the speed at which it is spreading across the community is very worrying," it said.
"Evidence from other jurisdictions, where the variant is already dominant also gives us cause for significant concern. In light of this, the clear advice from our medical and scientific experts is to delay any further relaxations to allow further monitoring of the situation.
"We are therefore regrettably not in a position to ratify the indicative dates provided for future relaxations. We will continue to monitor the situation very closely and look at all emerging data. The executive has agreed a new indicative date of 5 July, to be reviewed on 1 July."
It said the move was "similar to decisions that have been taken in England and Scotland to delay further relaxations to restrictions given concerns around the Delta variant".
The new variant was first confirmed in Northern Ireland in early May.
But health officials have warned that the next two weeks are vital in attempts to curb the spread with concerns about the rise in cases.
It came as modelling by the Department of Health to factor in the increased Delta variant transmissibility revealed the pessimistic, central and optimistic scenarios if the Delta variant is dominant by the beginning of July.
The central trajectory suggested there could be up to 1,200 new cases of coronavirus a day by the end of August. But that is dependent on 85 per cent of all over 18s receiving two doses of the vaccine by the end of August.
Under the optimistic trajectory, there could be between 50 and 100 cases a day, with a minimal number of Covid-19 inpatients.
However, the worst-case scenario suggests up to 6,000 cases a day by the end of the summer, but that has been regarded as"pretty inconceivable".
