People infected with the coronavirus might be sailing through checkpoints because of problems with temperature scanners. Thermal cameras and "temperature tablet" kiosks have been installed around the country since the pandemic began, in an effort to keep anyone with the virus from entering workplaces, schools, arenas and other public places. New research indicates the devices aren't effective, the Washington Post reports, so infected people are unknowingly allowed in settings where they can spread the virus. The readings are especially unreliable when several people are scanned at the same time. In issuing a public alert, the Food and Drug Administration this week warned that the devices could provide inaccurate readings if not used properly, causing "potentially serious public health risks." The FDA said it would send warning letters to companies selling unapproved thermal imaging systems.
IPVM, a surveillance research organization, said seven scanners in use employ an algorithm to compensate for the lack of precision in low-cost sensors, among other factors. But normalizing the readings skews the results, researchers say; someone with a core temperature of 100.4 degrees could register a safe 98 degrees. The FDA has said before that such devices aren't definitive in assessing whether a person has the coronavirus. Complicating the approach are the facts that someone can have a fever but not the coronavirus, or the virus but not a fever. Enthusiasm for the screening devices seems limited to those selling them, the Intercept says. "The utility of these devices as fever screeners is now highly questionable, and arguably a risk to public health," said the study's lead researcher, "because they actively report fevers as normal." The study is scheduled to be published by the Journal of Biomedical Optics. (Read more coronavirus stories.)