Published 26 June 2020
Covid-19 has gone down. A lot.* The estimated number of infections in London are less than 1,000 compared to +1 million in April. That is a significant fall and takes us to early March levels - the days when we still shook hands, hugged, and kissed each other at social events.
Perhaps this pent up emotion explains some of the anxiety in response to the BLM protests and other publicised gatherings. Or anger in response to social distancing rules being broken or relaxed too early. But there is not yet any (visible) sign of infections spreading more in the data - infections and deaths have both continued to fall (current data issues aside).
The worry with these data is that deaths are a lagging indicator and that new cases aren't being detected. Our previous analysis of the impact of Cheltenham and the Liverpool / Atletico Madrid Champions League games, which both took place in mid-March, showed that the lag is about 30-days. So we should have seen something in the data by now. So it is reassuring that reported infections have also continued to fall - despite a lot more testing since April.**
The evidence suggests less than 10% of the population have had the disease, so herd immunity does not explain the apparent lack of transmission.
The unanswered question is what has changed that has slowed the spread of the disease?
Without more data, it is hard to tell, but here are some thoughts or theories (it would be great if PHE could get better at sharing more data to test them!):
people are congregating but avoiding getting too close
summer sun is killing the SARS-CoV-2 virus when airborne
the people protesting were generally young and asymptomatic
people are wearing protection (e.g. face masks) and maintaining good hand hygiene
people more prone to catching it and showing symptoms in urban centres have had it already
the infection vectors (London Underground, Cheltenham, cricket, etc.) remain turned off
the virus has partly killed itself off
... a secret task force of furloughed workers cleaning the streets of London and other potential hotspots for catching Covid-19.
Whatever the reason, it does feel that society has achieved something unexpected by 'the science'. And a second wave seems less likely for now - the change in social attitudes and behaviours from early March is quite incredible when you think how different things are now.
Covid-19 is still in general circulation, and everyone needs to continue to be careful, but my view is that "Phase 2" will be more personal. The terrifying numbers of people dying in April will be replaced with localised outbreaks. The threat of Covid-19 could create more anxiety and social unease than the initial wave, particularly as the community spirit dies down, and we are left to make our own decisions. Indeed the disruptions going forward are more likely to come from a cautious approach to Test and Trace rather than a mortal concern or second lockdown.
What does this mean for the NHS:
Infection control. A priority has to be infection control. Before the crisis, this was a less well understood and more tolerated issue; now, it is top of the agenda - zero hospital-acquired infections should be the goal. It will mean changing the way of working, and this will reduce productivity.
Backlog. In April we estimated that the backlog would grow by 2.1 million cases. It may well grow by more, but at the moment many of these cases have not yet hit hospitals as referrals from GPs are still below normal levels. Diagnostics, as well as theatre capacity, will be essential for managing this demand safely. (We will be covering more on this in the next few weeks.)
Winter. There is a lot of uncertainty of what could happen after September. Covid-19 could come back, mainly if we relax and decide to take the Underground on a cold and wet day. Equally, our improved societal hygiene may well mean a drop in flu cases - as being seen in Australia. Planning for this uncertainty will be difficult, so scouting the data for early warning signs will be critical - better data from PHE would help!
So what is the priority?
Amidst the uncertainty, more and better data from PHE on infections is vital: confirmed infections, location, age, gender, etc. This information will help identify risk and help everyone manage it better. Sitting on the data is unethical if sharing it could also help spot outbreaks and save lives. Singapore, France and other countries are miles ahead in terms of the information they share publicly. PHE has the platform to share data in the UK, so I have no idea why it is not being used to greater effect!
----- * At its peak, a positive case of covid-19 was identified for every two tests - 50% rate of discovery. This has now fallen to well below 5%.