A 55.8% rise in the number of positive Covid-19 cases identified in Derry city's BT48 postal area is behind an overall increase in the county's figures.
The number of cases in BT48 rose last week to 120 from the 77 recorded over the previous seven days, while in Magherafelt, cases almost tripled across the week.
In a week that saw a 28.6% increase in tests completed however, the number of positives rose largely in tandem with the number of positive cases (25.3% increase).
The number of tests completed last week rose by almost 30%.
Outside of Magherafelt and Derry city, all other postal areas experienced a decrease in cases, bar Portstewart's BT55 postal area, which recorded one case. Last week it had been zero.
8.1% of Covid tests completed in BT48 over the last seven days were positive, as were 4.4% of tests completed in Magherafelt. All other areas had a positive rate of below 2%.
BT48's rate per 100,000 of population (197.2) is the second highest in Northern Ireland, behind only Augher (BT77), where just six cases was enough to push its rate to 382.2.
The rate per 100,000 population in the county rose again to 85.5, over double the overall NI rate of 41.0, while Portstewart's rate of 12.2 was the lowest in the county.
A further two Covid-related deaths were recorded across County Derry's local government districts over the last seven days; one in Causeway Coast and Glens and one in Mid Ulster.
For the third week in a row, there have been no Covid-related deaths in Derry City and Strabane.
Nine patients are being treated for the virus in Altnagelvin Hospital and a further 18 at Antrim Area Hospital, while the numbers across both the county's health trusts fell by three.
863,712 first doses of the Covid vaccine have been administered, a figure which represents 46% of the NI population, while 273,619 (14%) have received their second dose.
Meanwhile, an opportunity has emerged for those between 35 and 39 years old to avail of advance appointments to receive the vaccine.
The appointment process for those in the age bracket is due to open at the end of April, but limited appointments are now available, mainly at the vaccine centre in the SSE Arena, Belfast.
Health Minister Robin Swann said those eligible should seize the opportunity.
“Getting the vaccine not only protects you but also those close to you,” he said.
“I would also strongly encourage anyone aged 40 years or over who hasn’t booked themselves a vaccination appointment yet to do so as soon as possible.
“I have always been clear that we would move through the vaccine programme as quickly as vaccine deliveries and capacity allows as recommended by JCVI (Joint Committee on Vaccination and Immunisation).”
“Opening up to 35-39 year olds earlier than expected is a testament to the hard work and dedication of all staff who are delivering the vaccination programme in Northern Ireland.”
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