I downloaded the Covid-19 data up to 5 July from the JHU Github today and plotted smoothed new cases per day (average over last 7 days) as rates per million population by world region. The dramatic difference in trajectories for Western Europe and the Americas is obvious. Rates in all other regions are rising except for East Asia and Pacific, which is dominated by China. Australia, New Zealand, Japan and South Korea are also included in that region.

I thought it would be interesting to take a closer look at the situation in the USA, as North America appears to have the most out-of-control epidemic.  I classified the US states into blue and red, according to the popular vote in presidential elections. A state was blue if a majority voted for the Democrat candidate in more than half of the last four elections and red if it voted for the Republican candidate in more than half.  For three states which voted two times for each party’s candidate, I used the five last elections to break the tie.

The first peak in April for the blue states is dominated by New York. However from early June with premature re-opening of blue states there has been dramatic growth in new cases at a similar rate to the early stage in late March, and all benefits of the lockdowns have been wasted. There is now an upwards trend in blue states as well starting later in June.

I’ve done some back of the envelope calculations of the worst case scenario where growth in cases is not brought under control and the infected population reaches the estimated herd immunity level of around 60%.  Recent data from Geneva confirms other studies that have estimated the overall infection mortality rate at 0.6%.  Assuming infection fatality rates do not decrease due to improving treatment regimes, that would mean there would be approximately 1 mllion further deaths in the USA. After I had done this calculation, I came across a post by an Australian infectious disease expert which also predicts a worst case death toll of 1 million deaths for the USA.