Cases have increased by 1.6% since lockdown was eased
Hammersmith & Fulham borough has seen only a small increase in the number of recorded coronavirus cases since the start of July, despite the easing of lockdown.
Since 2 July there has been an increase of just 1.6% to breing a running total of 767.
The boroughs of Westminster and Kensington & Chelsea, and have seen percentage increases of 3.3 and 2.3 to 895 and 572 cases respectively.
It suggests Londoners have succeeded in containing the spread of the virus by taking precautions such as wearing masks, social distancing and working from home in order to keep transmission levels low.
July 2 was an important date because it was the first time the government started publishing a full picture of all positive tests that had taken place across the country.
Until July 1, the Government’s ‘coronavirus.data.gov.uk’ website was only showing so-called ‘Pillar 1’ data, which refers to tests carried out in hospitals, care homes and GP practices. But from July 2, the official figures also included tests carried out “in the community”, or ‘Pillar 2’, which refers to tests from drive-in centres or posted to individual households.
This meant that every borough in the country saw a small spike in cases between those two dates.
The figures for July look encouraging. But Dr Nim Pathy, an expert in mathematical epidemiology at Imperial College London, explained that the number of reported cases is likely to be much lower than the true number of people who have had the virus.
Speaking to the Local Democracy Reporting Service, he said: “The majority of cases that are being reported are only a fraction of the number of cases in the community.
“It’s helpful to think about, as an individual, what needs to happen before you to become part of those official numbers.”
Dr Pathy continued: “You need to be infected and develop symptoms. Then you have to be severe enough to be given a test, and finally that test would have to be positive.
“A lot of people don’t develop symptoms, and there’s a lot of very mild infections going on as well. It will seem like they have the sniffles and they won’t go to a GP or hospital for a test.”
“That whole chain of events needs to occur for you to become part of those [official] numbers.”
In April, the British Medical Journal published a study which suggested 78 per cent of COVID-19 carriers do not experience symptoms, although studies have varied.
Dr Pathy added: “In the UK we’re in a good position, as someone who presents in hospital needing a test is likely to get one. Everything to do with testing in the UK is fairly robust.”
Tracking the number of cases in the three boroughs, there have also been times when the running total of cases dropped from one day to the next. This happens when Public Health England corrects a duplication in the number of positive cases.
Duplications happen accidentally when a person is tested twice, which can happen because there are two types of test. Serological tests detect if someone had the virus in the past, and PCR swab tests can tell if someone has the virus at present.
Owen Sheppard - Local Democracy Reporter