Tony McDonough looks at the science of coronavirus and the ‘madness of crowds’ and whether the chaotic scenes of Liverpool supporters on the waterfront will lead to a surge in infections
In the last few weeks there has been a collective horror each time we have seen crowds of people gather outdoors in one place.
There was the VE Day celebrations (who can forget the conga in Warrington?), the Black Lives Matter demos, packed beaches at Bournemouth and the scenes outside Anfield, and at the Pier Head, following Liverpool’s Premier League triumph.
It has cemented the idea in many peoples’ minds that such gatherings make a second wave of COVID-19 inevitable. Are they correct?
As so often with this novel virus, we cannot be 100% certain. Scientists are still unravelling the complex dynamics of transmission. However, the growing evidence from multiple studies around the world is that transmission is far more likely in indoor settings than in outdoor ones.
Following the outcry over the scenes in Bournemouth and Liverpool, Professor Francois Balloux of University College London, weighed in. He urged us to stay calm and not to jump to conclusions.
He explained: “COVID-19 really doesn’t seem to transmit well outdoors. It may be because people spend less time in close contact. Other factors such as wind and UV light likely play a role.”
Prof Balloux cited a study from China, carried out by researchers at Southeast University, The University of Hong Kong and Tsinghua University, which looked at 320 coronavirus outbreaks and found that only one outbreak was due to outdoor transmission.
The researchers said: “318 outbreaks with three or more cases were identified, involving 1,245 confirmed cases in 120 prefectural cities. We divided the venues in which the outbreaks occurred into six categories: homes, transport, food, entertainment, shopping, and miscellaneous.
“Among the identified outbreaks, 53.8% involved three cases, 26.4% involved four cases, and only 1.6% involved 10 or more cases. Home outbreaks were the dominant category (254 of 318 outbreaks; 79.9%), followed by transport (108; 34%).
“Most home outbreaks involved three to five cases. We identified only a single outbreak in an outdoor environment, which involved two cases.
“Conclusions: All identified outbreaks of three or more cases occurred in an indoor environment, which confirms that sharing indoor space is a major COVID-19 infection risk.”
Of course, that doesn’t let the people gathering in large crowds here in the UK off the hook. The risk of outdoor transmission may be much lower, but there is a risk nonetheless. People still need to observe social distancing as much as possible.
It could be said that the Black Lives Matter protests in most cities (apart from the chaotic and violent London gatherings), including Liverpool, were calm, peaceful with most people observing social distancing and/or wearing masks.
The same could be said for the people gathering on the beach at Bournemouth. Despite the deceptive angle of the pictures, it is likely most people stayed in their own family or friends group and kept interaction with other groups to a minimum.
However, the ‘celebrations’ at the Pier Head in Liverpool are more alarming. There was lots of sustained close contact, shouting and singing – all identified as significant risk factors in the transmission of COVID-19.
It will be interesting to see what, if any, affect those chaotic waterfront scenes will have on local infection rates over the next few weeks.