There has been a major emphasis on the importance of widespread coronavirus testing as a tool to fight the pandemic.
But one expert says that people need to understand the limits of testing.
"Intuitively it seems like more testing is always a good thing, but there are downsides," said Dr. Michael Hochman with the USC Keck School of Medicine and host of the "Healthy Skeptic, MD" podcast.
He explained that if a person who was exposed to the virus gets a negative test result, "it would potentially be a false sense of reassurance."
Public health guidance says that regardless of the test result, anyone who is in close contact with someone who has the virus should quarantine for two weeks. It can take several days after someone has become infected to test positive for the virus.
Patients can also test positive long after they have recovered and the infectious phase of the illness has passed.
"I’ve had patients who have been required to have a negative test in order to be allowed to go back to work, and this is weeks after their illness has been resolved," said Dr. Hochman. "Unfortunately those tests keep coming back positive and we can’t get them back to work even though they’re clearly at a stage that’s no longer infectious."
Of course, testing is vital from a public health perspective.
Catching a new case of COVID-19 means that the patient and all of their contacts know to go into quarantine, limiting new cases. It also helps officials to track the spread of the pandemic.
"These tests are a piece of information," said Dr. Hochman. "But they are not the be all and end all."
Testing is a key piece of the puzzle in slowing the pandemic, but a negative test result is not a substitute for responsible behavior.