Originally posted on April 27th, 2020 on Facebook
On April 22nd, I showed you data with a big increase in cases from the previous few days. Several outlets have confirmed that increased testing is leading to this apparent big increase in cases. The Johns Hopkins site that I get my data from has started releasing testing numbers as well, but I haven’t been collecting those. I’m going to start, but it will be awhile until I can meaningfully integrate that information. Labs often release reports in big batches, so this makes the graphs like mine look erratic. For the US, California, and San Diego County, there is an apparent increase in cases for the last week or so. Much of this is because of increased testing. As testing catches up to real cases, we’ll know better what our real case load is.
Some good news is that the site I introduced on April 20th, rt.live, has made some revisions to their model. They claim they’ve corrected for the increase in testing, and now most states are seeing a nice downward trend, and all but 7 have an Rt value below 1. This means that each infected person is passing the virus on to less that 1 other person, so the virus is slowly going away in that state! That is great news! This will also impact what states can move into the 1st reopening phase.
A doctor friend of mine says that the number of deaths per day is perhaps the most reliable way to tell for certain that the virus is receding, because this number is not confounded by the number of tests being given. This is certainly true. Unfortunately, deaths sometimes occur weeks after infection, so it takes a long time to see the impact of a change in behavior if we wait for the number of deaths to inform us. So no number is perfect. Also, there has been controversy about how deaths are reported. Some cases of COVID have been confused for flu or other pneumonia and vice versa. Only the reporting physician may know all the factors going into that decision, so we often can’t figure this out by looking at the numbers.
Our efforts are having big impact, and several states will start reopening today! We can certainly hope they will be successful.