FYI
Hi Everyone,
Trends are pretty much the same as I reported last time, so this will be brief. The number of recorded new cases in the US is still at a plateau (Fig. 1), while the number of tests per day continues to rise (Fig. 2), which is a good thing, though we’re nowhere near where we need to be on this. The number of new cases per test (Fig. 3), which I argued last time is a good measure of the relative number of new cases per day over time, continues to decline, which is great news. Cumulative new cases per test still fits a modified logistic growth curve extremely well (Fig. 4), and projections from the fitted curve indicate that we will reach 95% of total cases in the first wave on day 78 (17 May) (Fig. 5, red line). That’s 3 days later than my last projection, the difference being well within the margin of error. Finally, new deaths in the US seem to have plateaued (Fig. 6), though there is not yet a sign of a decline.
All things considered, pretty good news for US infections.
Fig. 1 Fig. 2
Fig. 3 Fig. 4
Fig. 5 Fig. 6
We’re seeing a similar trend in NC infections. The number of new cases recorded per day continues to rise (Fig. 7), but this seems likely to be due to an increase in the number of tests per day, since the number of new cases per test continues to decline (Fig. 8). The cumulative new cases per test fits a modified logistic growth curve vary well (Fig. 9), and the projection from that curve indicates NC should reach 95% of cases in the first wave on Day 5 (14 May), the same as in my last update.
Fig. 7 Fig. 8
Fig. 9 Fig. 10
In summary, the news seems to be good, with new cases per test falling rapidly and the end of the first wave expected around 14-20 May, based on the date for 95% cumulative cases/test. As I’ve said before, though, there will still be a substantial number of new cases after those dates, so we can’t relax social distancing yet.
Finally, passing of the first wave does not mean we’re out of the woods. As you’ve probably been hearing from the media, there’s a high chance that there will be a second wave that will hit sometime in the fall. We need to be ready for that, which among other things means a vast increase in testing and monitoring capabilities.
Take care and stay safe!