Coronavirus infections are on the rise in England, figures from the Office for National Statistics (ONS) suggest.
A sample of households in England, excluding nursing homes and hospitals, was taken to test for the current infection.
The ONS says daily cases have increased from about 2,800 to 4,200 since last week.
However, there is not enough data to suggest a higher proportion of positive tests in any given region.
The ONS estimates of daily cases are higher than those reported by the Department of Health and Welfare because they include people without symptoms who otherwise would not have requested testing.
Confirmed cases reported by the government for the same period were between 339 and 721 per day over the same period (July 20-26).
About 350,000 people have been newly tested for the coronavirus, not counting those tested as part of the ONS surveillance study.
These are tests involving a swab from the nose and throat that can diagnose a current active coronavirus infection, but do not show whether someone has had the virus in the past.
Despite ONS figures suggesting an increase in infections, the official estimate of virus reproduction or R count (a measure of rising or falling cases) for England was between 0.8 and July 1 to 31.
An R number less than one indicates that the number of infections is decreasing.
It is calculated using a range of different measures, including hospital admissions and deaths.
Because it takes time for an infection to progress to hospitalization and, in the worst case, death, there is a time lag.
The latest estimate of R may not capture more recent increases in infection.
The ONS has regularly tested a sample of the population, whether or not it has symptoms, and may therefore be better placed to detect an increase in cases in the population at an early stage, before they result in illness and hospitalization.
Although this is an estimate based on a relatively small number of people, taking this uncertainty into account, the ONS believes that there is now enough evidence to suggest a ‘slight’ increase in new infections in England in recent weeks, for the first time since May.
This increase, however, is far from the levels observed earlier in the year.
BBC Statistics Officer Robert Cuffe explained: “In early March the number of cases we were seeing was doubling every three to four days – very, very quickly.
What we are seeing described in the last few weeks is a rate of cases that is doubling every month and a half, every 2 months, so they are increasing very slowly. “