Good news from a population screening study
by Ronald Bailey
Preliminary results are out from a COVID-19 case cluster study in one of the regions worst hit by Germany’s coronavirus epidemic. They are somewhat reassuring.
One often-heard statistic is the “case fatality rate”—that is, the percentage of people diagnosed with a disease who will die of it. This afternoon that figure stands at 3.5 percent for COVID-19 in the U.S., but this rate is significantly inflated because it does not count asymptomatic cases or undiagnosed people who recover at home. What we really need to know is the infection fatality rate: the percentage of all the people infected who eventually die of the disease. That’s what the German study attempts to do.
Over the last two weeks, German virologists tested nearly 80 percent of the population of Gangelt for antibodies that indicate whether they’d been infected by the coronavirus. Around 15 percent had been infected, allowing them to calculate a COVID-19 infection fatality rate of about 0.37 percent. The researchers also concluded that people who recover from the infection are immune to reinfection, at least for a while.