For the last two weeks (ending September 12), all of the national COVID metrics again showed continued improvement with positive test results, fatalities and hospitalizations all falling around 15%.
Testing
The number of positive tests reported daily fell from about 42,000 to 37,000. That is lowest level since late June. The daily number of tests completed drifted lower from about 725,000 to just under 700,000. The decline accelerated in the back half of the two-week period. The decline does not appear to relate to testing capacity but instead to people’s interest in getting tested. Few are going to go to the hassle of being tested unless they are sick or are required to do so to go back to school, work, get a medical procedure or some other similar circumstance. The positivity rate also continued to trend down, falling to 5.16% for Week 37.
The controversy around testing continues. It is now abundantly clear that referring to positive test reports as “new cases” is extremely misleading. This article in Bloomberg documents that here in Harris County many of the so-called “new cases” were actually tests from weeks, or in some cases even months, before. This means that the positivity rate and the R(t) calculations have little value as indicators of the current level of infection.
Fatalities
The summer increase in fatalities topped out in Week 31 (ending August 1) at a daily average of just over 1,100. Since then fatalities have declined steadily, reaching an average of 710 last week. The rate of decrease accelerated over the last two weeks.
The four-week lagging case fatality rate has now been below 2% for the last six weeks and fell to 1.35% last week, the lowest level since the pandemic began.
Hospitalizations
Hospitalizations also continued to decline over the past two weeks and are now approaching the levels prior to the summer surge in cases. ICU bed usage and those on ventilators also dropped. The of number of patients on ventilators fell by 22%, a further indication that ventilation is increasingly becoming a last resort treatment.
Summary
All indications are that the levels of infection, and in particular, of serious disease, are on the decline. Of course, we do not really know why but most likely it is the result of the combined effects of the various suppression efforts we have adopted and growing naturally acquired immunity. So far, there is no indication that Labor Day or schools restarting have set off a new surge but it is early. In a couple of more weeks we should have a better read on how those factors are going to affect the course of the pandemic.
