This 12 months, as they put together to let turkeys brine and pie crusts thaw, folks throughout the nation are ready for one thing further: a coronavirus test they hope can clear them to mingle with family members.
Because a optimistic test filters out individuals who ought to positively not be out with others, many individuals contemplate a negative coronavirus test to be a ticket to freely socialize with out precautions. But scientists and docs say this is dangerously misguided.
The essential cause is that a test offers details about the extent of the virus on the time of the test. An individual may very well be contaminated but not have sufficient virus for it to register but. Or, a individual could change into contaminated within the hours or days after taking a test. Also, the exams do not have 100% accuracy.
“If you require all of your guests to email you a negative test result before your Thanksgiving dinner, it will definitely decrease the risk of an outbreak — but not completely,” stated Dr. KJ Seung, chief of technique and coverage for the Covid response at Partners in Health. Yet that is a frequent misperception contact tracers hear when speaking to folks, he stated.
Laboratory exams that depend on a approach known as polymerase chain response, or P.C.R., can detect the virus when it’s current even at very low ranges. But it would take a couple of days to return outcomes, leaving time for somebody to be uncovered.
Antigen exams are sooner, inexpensive and extra handy — they will ship leads to a matter of minutes — but are additionally extra vulnerable to lacking the virus when it’s scarce. And that might give somebody a false sense of safety en path to Thanksgiving dinner, stated Paige Larkin, a scientific microbiologist at NorthShore University HealthSystem in Chicago, the place she makes a speciality of infectious illness diagnostics.
“A negative result is a snapshot in time,” Dr. Larkin stated. “It’s telling you that, at that exact second you are tested, the virus was not detected. It does not mean you’re not infected.”
In abstract, as Dr. Esther Choo, an emergency drugs doctor and a professor at Oregon Health and Science University, put it: “Testing negative basically changes nothing about behavior. It still means wear a mask, distance, avoid indoors if you can.”
Sorry, but a negative test does not give you a green light for Thanksgiving. The British Journal Editors and Wire Services/ Pehal News.