Overall rates of respiratory infections fell from 20.4 to 3.3 per 10,000 after the lockdown was introduced.
“Rates of upper respiratory tract infections and lower respiratory tract infections have fallen significantly since March when social distancing measures were introduced,” the researchers added. “Some of this fall would happen naturally at this time of year with the onset of spring.
“The observed reductions in upper respiratory tract infections and lower respiratory tract infections suggest that most of the effect on rates of transmission occurred through the encouragement of social distancing.”
The figures from the ONS are the first results from surveillance efforts to try to gauge how many people in the community are infected.
The pilot survey will eventually involve 10,000 households in England, with all individuals aged over two years invited to provide samples for testing – meaning approximately 25,000 people will be involved. So far, swab test results have been collected from 7,087 people between April 26 and May 8.
The Government is keen to see how many new cases have occurred in a given time period and how many people are likely to have ever had the infection. Officials are also calculating how many people are asymptomatic and will release those figures shortly.
Separate work at the Government’s Porton Down laboratories to find out how many people have had the virus and recovered is ongoing.
The data will enable better estimates of the rate of transmission of the infection, often referred to as ‘R’.
Professor Chris Whitty, the chief medical officer, and Sir Patrick Vallance, the Government’s chief scientific adviser, have consistently said that keeping the ‘R’ rate below one – meaning one infected person infects fewer than one other person – is crucial to allowing the lockdown measures to be lifted.