Today I have a weekly update on cases, followed by some speculation on what it means. As we’ve seen before, the United States has a slowly diminishing daily new case load for confirmed cases. Death rates for the US, perhaps a better measure than confirmed cases, are also slowly diminishing. Several sites seem to be accepting the data from Sutton et al (Universal Screening for SARS-CoV-2in Women Admitted for Delivery, NEJM, April 22, 2020) to estimate that actual cases is 8 times that of confirmed cases. California continues to have a slowly increasing caseload.
According to the John Hopkins University COVID site, LA County accounts for a full 48% of cases in California, with Sierra and Trinity Counties, in the East and North having just 1 case each. Cases are definitely centered in urban areas, mostly in Southern California. Daily death number in California appear to be perhaps flat. Interestingly, with all of these graphs, California daily deaths in particular, there is a clear weekend effect, with a weekly low in numbers on Sunday or Monday of each week. So when you look at the daily caseload for the US, with it’s jagged Sierra-like peaks, you’ll know it’s because health-care workers take the weekend off too, and reporting is being done during the week! San Diego’s numbers continue to be relatively flat.
What we would like to see now is a lowering in the number of active cases. Unfortunately, this highlights a problem in all of this, how health departments define a “recovered” case. San Diego has just begun to report recovered cases. The reported numbers suggest that cases resolve in about 16 days after confirmation on average. For the US, reported recoveries suggest that patients recover in 50 days. California doesn’t report recoveries at all. Each entity defines a recovered case differently, so it will be difficult for us in the public to tell how many have recovered.
Reports from last week regarding the possible failure of lockdowns to bring numbers down are causing a lot of speculation on line as to the best way to improve. Many Western countries are struggling to reduce the number of new cases, and many countries are only now having their initial surge in cases (see my May 24th post).
In the US, several states are creeping back toward an R0 of 1.0 after re-opening. We definitely want to stay below 1.0, as this indicates a slowly vanishing caseload. Texas was doing very well for a long time, but the R0 there is above 1.0 for the first time in quite a while. Cases are predominantly in urban areas, Houston, Dallas, and Austin.
A lot of studies are being done on the best approach. Japan is of particular interest because after an initial very small peak, they had a much larger peak starting in late March. They didn’t have the massive testing of So. Korea, nor did they have a strict lockdown. But they got things back under control quickly, and they have a very low daily caseload now, despite the VERY high population density of cities like Tokyo. So far, people are speculating that they are doing well because it’s culturally acceptable there to wear masks on a regular basis, and others are just calling it a mystery. I’m sure researchers will be taking a close look at Japan.
All the best to you and your family!
Don’t fear, but be smart,
Sutton et al (Universal Screening for SARS-CoV-2in Women Admitted for Delivery, NEJM, April 22, 2020):