“You are maximally infectious before you exhibit symptoms, if you exhibit any symptoms at all,” Dr. Paltiel said. “You can be exposed and incubating the virus, and be beginning to shed massive amounts of transmissible virus and be a superspreader, without actually exhibiting any symptoms like a fever.”
Temperature checks will do nothing to stop these “ticking time bombs,” he said. “It’s a bad idea.”
Instead, he said, restaurants should push for access to rapid turnaround, point-of-care tests for patrons.
Interestingly, even seriously ill coronavirus patients who need medical attention don’t always have a temperature. Of nearly 6,000 patients in the New York area who were so sick last spring that they were admitted to Northwell Health hospitals, only 30 percent were febrile when they came in, according to a study by Dr. McGinn that was published in the Journal of the American Medical Association.
The trend is consistent with earlier reports, including a study from China that looked at more than 1,000 patients admitted to 552 hospitals through the end of January. The study, published in the New England Journal of Medicine, reported that only 44 percent of the patients had an elevated temperature when they were admitted, though most (88 percent) developed a fever during the course of their hospital stay.
In July, the C.D.C. quietly updated its guidance to businesses, acknowledging that symptom and temperature checks “will not be completely effective” because asymptomatic individuals and those with vague symptoms will pass the screenings.
