Causeway Coast and Glens has recorded a significant surge in positive Covid test results - from 329 (for the week ending November 4) to 503 (for the week ending November 12).
On Friday, Causeway Coast and Glens' infection rate was by far the highest in the Province.
It had risen over seven days from 228 per 100,000 of population to 348.
In the preceding weeks Department of Health figures for the borough had been showing a downward trend
Figures for Derry/Strabane and Belfast, which have recently topped the infection rate league tables, stood at 201and 198 respectively.
The highest concentration of cases is in the BT52 area which covers Coleraine east of the Bann.
Though infection rate spikes usually take some time to affect hospital admissions, the number of Covid inpatients at Causeway Hospital has already risen from 17 to 27 over the same period, according to the latest figures.
Read much more in next week's paper.