For the last two weeks (ending October 24), there were clear signs of increasing infection in the US as hospitalizations and new positive results rose significantly. Fortunately, fatalities saw a relatively modest increase.
The number of COVID patients hospitalized in the US increased during the last two weeks by 21%, ending the two-week period at about 42,000. The two previous waves of hospitalizations topped out at about 60,000. More ominously, ICU bed and ventilator usage increased by 28% and 40%. While over 90% of hospitalized patients survive, the survival rate for those ventilated has been very poor.
This surge has been somewhat different from the previous ones, in that the hospitalizations are more disbursed across the country and not as concentrated. The only state that I have seen with potentially critical overcrowding issues has been Wisconsin.
After almost three months of steady but modest declines, average daily fatalities took an upturn in the last two weeks, averaging 750 versus 683 for the previous two weeks. For context, that is about 10% of what daily fatalities were in the US in 2019 for these two weeks.
The 4-week lagging case fatality rate improved slightly to 1.8%. We will have to watch that carefully over the next few weeks to see if that number holds or, hopefully, declines with the recent increase in new positive test results.
The IHME model lowered its fatality estimate for year-end again, this time to 317,000 from its previous estimate of 347,000. That still represents about twice the current level of fatalities which seems very unlikely to me. I suspect we will see them lower their estimate again in the next week or so.
The US continued to increase testing, averaging over 1 million test results daily for the last two weeks for the first time. Cumulative test results now equate to 41% of the US population. Of course, that does not mean that 41% of the population has been tested because many people have been tested more than once. And this does not include antibody tests. It is an incredible accomplishment. Kudos are in order for the testing companies, hospitals, clinic, public health agencies, and especially those frontline healthcare workers who have stood for hours on end by lines of cars to collect the swabs.
While testing increased by 10%, new positive test results increased by 34%. This suggests that about a third of the increase in “new cases” are the result of increased testing but that about two-thirds is due to spreading infection. The ratio of tests coming back with a positive result moved up from 4.7% to 5.8%.
Over the last two weeks, there have been clear indications that COVID is spreading more rapidly. However, this surge has differed from the previous two in that it has been more disbursed across the country. There has been concentration in the upper Mississippi River watershed as indicate by this map from the New York Times, but just about everywhere is seeing either flat or increasing metrics, including even places like New York and New Jersey. Few regions are seeing a further decline.
It appears to me that every region is going to inevitably have spike in infections and serious illness. However, after that initial spike in cases occurs, it appears that our current toolbox of suppression methods gets the spread of the serious illness to a, more or less, steady state.
If that trend holds, we will be in a slow grind until we get the vaccine. This is a possible scenario that Johns Hopkins epidemiologist, Jonathan Lessler, described in this Washington Post article . That scenario is not consistent with some of the apocalyptic projections for this winter. Of course, no one knows, and we are all guessing at this point. But a massive spike this winter would not be consistent with how the virus has behaved so far.