COVID-19 false negative test results if used too early

Johns Hopkins Medicine

In a new study, Johns Hopkins researchers found that testing people for SARS-CoV-2 -- the virus that causes COVID-19 -- too early in the course of infection is likely to result in a false negative test, even though they may eventually test positive for the virus.

A report on the findings was published in the May 13 issue of Annals of Internal Medicine.

"A negative test, whether or not a person has symptoms, doesn't guarantee that they aren't infected by the virus," says Lauren Kucirka, M.D., Ph.D., M.Sc., obstetrics and gynecology resident at Johns Hopkins Medicine. "How we respond to, and interpret, a negative test is very important because we place others at risk when we assume the test is perfect. However, those infected with the virus are still able to potentially spread the virus."