From The Atlantic:
"How many people have the coronavirus in the United States? More than two months into the country’s outbreak, this remains the most important question for its people, schools, hospitals, and businesses. It is also still among the hardest to answer. At least 630,000 people nationwide now have test-confirmed cases of COVID-19, according to The Atlantic’s COVID Tracking Project, a state-by-state tally conducted by more than 100 volunteers and experts. But an overwhelming body of evidence shows that this is an undercount."
The story points out that "there is clearly some group of Americans who have the coronavirus but who don’t show up in official figures," such as homeless people and people who die at home but are not reported as victims of the pandemic. "Now, using a statistic that has just become reliable, we can estimate the size of that group - and peek at the rest of the iceberg."
Here's where it gets a little scary: "According to the Tracking Project’s figures, nearly one in five people who get tested for the coronavirus in the United States is found to have it. In other words, the country has what is called a “test-positivity rate” of nearly 20 percent.
"That is 'very high,' Jason Andrews, an infectious-disease professor at Stanford, told us. Such a high test-positivity rate almost certainly means that the U.S. is not testing everyone who has been infected with the pathogen, because it implies that doctors are testing only people with a very high probability of having the infection. People with milder symptoms, to say nothing of those with none at all, are going undercounted."
The Atlantic piece is sober-minded and nuanced, and worth reading here.
- KC's View:
The Atlantic points out that "the positivity rate is not the same as the proportion of COVID-19 cases in the American population at large, a metric called 'prevalence' … Prevalence is a crucial number for epidemiologists, in part because it lets them calculate a pathogen’s true infection-fatality rate: the number of people who die after becoming infected." But test-positivity remains a way of tracking how contagious a disease is, which can inform how governments, businesses, health care systems and even individuals decide to react to it.
The one thing that seems clear to me is that we don't really know how many people have it, and I am leery of reopening efforts that get ahead of this number. Not because I like being sheltered at home - like most people, I am anxious to get back that part of my life that has been subsumed by the pandemic - but because I hate the idea that things could get reopened only to get closed down again, which would be an enormous blow to … yes, governments, businesses, health care systems and individuals.