The B.1.617.2 Indian Covid variant - now known as the Delta variant - is becoming more prominent in areas of Nottinghamshire, latest figures show.
The strain, a sub-lineage of the original B.1.617 Indian variant, is still the most dominant in Nottingham city, but actual recordings of genomes have gone down.
Over the past two weeks, figures rose initially from 44.5 to 51.5, but they have since declined to 42 incidences.
Data from the Wellcome Sanger Institute in London - which is conducting Covid-19 genome (variant) surveillance - shows a breakdown for all the districts of the county.
Figures show the Delta strain becoming more prominent in parts of Nottinghamshire, while in others the Alpha (formerly known as Kent) variant is still most prevalent.
In Rushcliffe, there was an equal split of both mutations of the Covid-19 virus, where two weeks previous (May 15) there was no detection of the virus.
Below is a breakdown of the proportions of each Covid-19 strain and the actual number of incidences (in brackets) for two weeks ending May 29:
Nottingham - Delta 79.2% (42) - Alpha 15.1% (8) - B 4.7% (2.5) - Other 0.9% (0.5)
Gedling - Delta 76.3% (14.5) - Alpha 23.7% (4.5)
Broxtowe - Delta 58.1% (9) - B 22.6% (3.5) - Alpha 19.4% (3)
Rushcliffe - Delta 45.5% (2.5) - Alpha 45.5% (2.5) - B 9.1% (0.5)
Ashfield - Alpha 78.9% (7.5) - Delta 15.8% (1.5) - B 5.3% (0.5)
Mansfield - Alpha 92.3% (6) - Delta 7.7% (0.5)
Newark and Sherwood - 92.6% Alpha (25), 5.6% Delta (1.5), 1.9% B (0.5)
Bassetlaw - Alpha 60% (4.5), Delta 40% (3)
In nearby Leicester, 152 genomes for the Indian variant were recorded in the same time frame, making up 82.4% of the cases.
For further comparison, there were 837 genomes detected in Bolton during this same period - the most in any area of the country - which is 92.5 percent of all confirmed cases.
More than 30 areas of Nottinghamshire now have a coronavirus infection rate higher than that of the England average, according to the latest data.
It comes as the interim public health director for Nottingham, David Johns, said there were many "unknowns" as to how the Delta Covid variant (which originated in India) would impact infection rates.
