The Atlantic – No one’s actually sure….”At least so far, the official numbers in the U.S. don’t seem to show that a similar wave has made it stateside. But those numbers aren’t exactly reliable these days. In recent months, testing practices have changed across the country, as at-home rapid tests have gone fully mainstream. These tests, however, don’t usually get recorded in official case counts. This means that our data could be missing a whole lot of infections across the country—enough to obscure a large surge. So … are we in the middle of an invisible wave? I posed the question to experts, and even they were stumped by what’s really happening in the U.S…Not only is our understanding of case counts limited, but all the epidemiological data we do have in the U.S. is rife with biases, because it’s collected haphazardly instead of through randomized sampling, he said. The data sets we rely on—case counts, wastewater, and hospitalizations—are “blurry pictures that we try to piece together to figure out what’s going on,” Jennifer Nuzzo, an epidemiologist at Brown, told me.

An invisible wave is possible because cases capture only the number of people who test positive for the virus, which is different from what epidemiologists really want to know: how many people are infected in the general population. That’s always produced an undercount in how many people are actually infected, but the numbers are becoming even more uncertain as government testing sites wind down and at-home testing becomes more common. Unlike during past waves, each household can request up to eight free rapid tests from the federal government, and insurance companies are required to reimburse Americans for the cost of any additional rapid tests they purchase. These changes in testing practices leave even more room for bias…”