You might have noticed, I am obsessed with the idea that this coronavirus began circulating in the US much earlier than we realized and that a greater percent of the population has already been infected. The use of influenza data and other approaches to test this theory has been innovative and very useful and here is one more study, this one from the New England Journal of Medicine, along those lines. (NEJM Study) These researchers did coronavirus testing of every pregnant mother who came in for delivery at one hospital in New York. A total of 215 expectant mothers were tested. 4 had symptoms of and tested positive for coronavirus disease. Of the other 211, 29 or 14% were positive for coronavirus but asymptomatic. Three more developed symptoms while in the hospital and one person who had a negative test developed symptoms and a retest revealed that that person was infected. So if this is reflective of the experience of a large segment of the population (and pregnant women aren’t reflective of the whole population) the virus was pretty widely circulating and being transmitted. But around 88% of the population was asymptomatic. And there was a least one false negative test, and there may have been false positives as well. These patients were not tested for antibodies, it is certainly possible that they could have had an infection and cleared it. So again, there is good evidence to believe that our models are wrong in part because they are grossly underestimating the infection rate and therefore substantially overestimating the rate of severe illness and death as a percent of infections.
A piece of research from Japan found that it was likely that mitigation of spread measures, primarily hygiene related, had apparently reduced the incidence of influenza toward the end of the 2019-20 flu season. (JAMA Article)
Another article in the Journal of the American Medical Association discusses the mental health challenges certain to flow from the epidemic and more importantly, from the shutdown measures. (JAMA Article)
A study reported in the New England Journal of Medicine examined the results of coronavirus infection testing in Iceland. This consisted both of symptom related testing and some random population testing. About 6% of the entire population was tested. Rates were around 13% in the targeted testing group, symptomatic and recent travelers, but a little less than 1% in the group that was invited to participate in testing and .6% in random population testing. (NEJM Article)
An article at 538 discusses why we engaged in extreme shutdowns this time compared to other epidemics or potential epidemics, such as SARS, MERS, and swine flu. (538 Article) As they note, some of those infectious agents were not as transmissible as the current one and some were not as lethal (although we don’t really know how lethal this virus is yet, it may turn out to be the same as some bad flu strains). But they ignore the main reason in my judgment, which is excessive and sensationalized media coverage that stampeded weak-kneed political leaders into taking extreme actions that shut down society and the economy. That is the real reason.