The Senate hearings yesterday sounded pretty dire. Epidemiologists are increasingly worried about trends in the COVID-19 stats across the south. The positivity rates and hospitalization data are definitely headed in a bad direction. Unfortunately, given the politicization of all this, as well as the various playing on fears people have, you’re hearing contradictory arguments like “more testing is causing higher numbers” or “now younger people are getting sick so the death rate is (or will) go down” or “masks don’t work” or even “masks are more dangerous than not wearing one.” You’re also hearing “there is so much contradictory information and what was said in March like 3 million dead didn’t happen.” As noted earlier this week, it seems that in this case misinformation is more widespread and dangerous than “fake news”. Lets take a quick look at models and forecasts, then take a hard look at the bottom line.
First, how bad are the models? Actually, not that bad, and they are getting quickly better. Lets look at the country level data and a couple of the models at the national level:
Notice the difference between the black line (01 March global c19 estimate, day 30) and the Italy specific forecast on 15 March (day 45). The early forecasts (solid black and gray lines) seem low compared to the big outbreaks, but for most countries who took aggressive action wasn’t so bad. The forecast for Italy (green dashed line) made two weeks later is much better. The shape different due to their actions, but the end point, and the countries with similar outbreaks like the UK and Spain who took later action, are pretty close. That was a forecast make over two months ago, and we’ve learned a lot about the virus, and how it reacts to various public policy and personal activity decisions. Noisy, not perfect, but useful, actionable information.
When we look at Georgia, Florida, and South Carolina, things don’t look good. Consistently over June the cumulative number of dead on a given date is around 5% of the total who tested positive 21 days earlier. It has very slowly declined, but when you adjust for demographics of testing it’s remarkably constant. If we apply those trends over the next three weeks, adjust for expanding testing, etc., here is what we get. Day “zero” is June 1st, 2020, so the solid lines are what was observed in June. The dashed lines are the forecast for the first three weeks of July assuming the 5% ratio holds …
The SC data is pretty crummy, and may be worse than it looks. Georgia is in a slow burn. Florida is on the verge of a doubling its death toll over the next three weeks. It’s not good, even if the ratio is cut in half (not likely) by the changing demographics of younger people being the primary source of new positives.
Opinion and recommendation: I have mixed feelings about local city government mandating actions like masks. But this isn’t really the place to argue about the legal basis for these orders, or how in a community with complex overlapping jurisdictions like, for instance, Chatham County Georgia. It’s confusing and far less effective when one municipality mandates it and the others don’t (that’s a major reason why the shelter in place orders and reopening were ineffective, they weren’t uniform). Forget what your mayor says one way or the other. Forget the pedantic, technical nit-picking arguments over how effective masks are. The science is evolving, and there is a lot of seemingly contradictory information out there that, in context, does actually make sense. The bottom line is that even if only 20% effective at reducing transmission (and the vast majority of studies indicate that cloth masks are at least that good, and the layered stuff is even better than that), it has a good chance of dropping the reproduction rate below one, which will get the pandemic under control. Yes, N95 type masks do more to protect you than others. Yes, cloth or procedure/surgical masks mostly protects others. But the procedure masks do provide you with some protection – just as the N95’s do provide some protection for others. Yes, you can conceivably catch the virus from improperly taking off your mask – but that risk is a small fraction of your risk from catching it without one (note this is different in a clinical environment, where self-contamination is a bigger concern). So please just wear the mask when you go out in public to confined places, continue with good hygiene and social distancing. Learn how to properly put it on, wear it, and take it off. We know how to beat this thing, if people would just be sensible. But … remember actions today take three or four weeks to show up in the mortality stats. July is likely to be a rough month, with lots of fear, angst, and finger pointing. Sigh.