As we begin to think about returning to normal school and business, it is essential that we understand how many of us have been infected, which (hopefully) would give us immunity to future infections. Remember, we need 60% to 70% of a population exposed and infected or vaccinated and immune before we can really be safe.
This week’s The Economist has a provocative article entitled, “Why a study showing that covid-19 is everywhere is good news.” The data and logic are ingenious, the conclusions positive.
As a routine, 2,600 American clinicians file a report about the number of patients who present with (among other things) the number of patients they see who have an influenza flu-like (ILI) illness (temp > 100 and a cough or sore throat without a known cause). In normal times, these reports mirror the fluctuations in the influenza epidemic and give epidemiologists another view of how many people might have been infected.
But now the pattern is breaking. ILI reports are increasing, a lot. This new pattern also 1) parallels the number of reported covid-19 cases by state, low in Kentucky and high in New Jersey; and 2) rises 3 weeks before the deaths in any state rise (consistent with the 3-week timeline from infection to death).
So what does this mean for us mere mortals? Well, here comes the good part: Using this tool, the number of ILI cases between March 8 and 28 was 200 times the number of test-positive covid-19 cases.
Wow, assuming the numbers are close to correct, that conclusion is so important. First, it indicates that the virus kills a smaller percentage of those infected than we thought; and second, that a whole lot more of us might have been infected and hopefully developed immunity. This can and will be confirmed once America rolls out 10 million antibody tests. But until then, this news from the ILI case reports is very positive. Let’s hope it is correct.
Yes, during this study period America was (and is) still not testing nearly enough people. But even if the numbers are off by a factor of 10, this is still good news because it gives us a feel for the large number of asymptomatic people are out there. Let’s hope.
Practice safe living.