Have the protests started the second wave of Covid-19? (update after 9 June data)
for original discussion see here
It is now day 14 after death of George Floyd. Total US incidence of daily cases remains approximately the same as the day of his death.
The median incubation time is about 5 days after exposure and about 97% of people who develop symptoms will do so within about 11 days. Add another 2 days before symptomatic people get tested and another 2 days before results are reported I would expect to see daily incidence changes start to appear from about day 10 post-exposure. The cities I have selected all had rallies before 1 June so if we are not seeing increased incidence by now I am becoming more confident that they are not going to happen.
Minneapolis was the first to have protests on 26 May, 14 days before my current data. It continues to show a decline in new cases.
Despite a small increase in today's data the overall trend is still down. The daily incidence is quite low, being below 100 people per day. It is normal to see flattening of the curve post-peak as we are seeing here (check the New York curve below for an example)
Los Angeles appears to have plateaued in the short term and appears to be starting a downward trend (but this could easily change).
Fulton (mainly Atlanta) is currently averaging fewer than 50 new cases per day and continues its downward trend.
Incidence in New York City also continues to fall slowly.
There are no significant changes in incidence trends over the last few days I have been looking at this. None of the cities I am looking at are showing increased SARS-CoV-2 incidence at this stage. Neither does the USA as a whole.
It is still too early for me to call definitely but so far the data supports my hypothesis that transmission in outdoor environments such as occurred during the recent protests is much lower than many were expecting. I will continue these updates for another week or so.
There have also been many massive rallies in other countries. Most of these happened around about June 6 which is still too early to look for changes in daily incidence. I will look at these in a few days.
If these trends continue over the next 2 weeks or so I think this provides strong evidence that outdoor restrictions can be eased from current levels.