WASHINGTON — QUESTION:
Can a COVID-19 patient continue to test positive days or months later? If so, is that patient still contagious?
Yes, someone who tests positive for the COVID-19 virus can continue to test positive for weeks and months later according to our experts.
It is still unknown whether patients continue to be infectious during that time.
Centers for Disease Control and Prevention- "When you can be around others after you had or lively had COVID-19," "Duration of isolation and precautions for adults with COVID-19" and "Updated isolation guidance does not imply immunity to COVID-19"
Korea Disease Control and Prevention Agency- "Findings from investigation and analysis of re-positive cases"
Dr. Stuart Ray- Vice Chair of Medicine for Data Integrity and Analytics and Professor of Medicine- Johns Hopkins Medicine
A viewer asked us to verify whether you can continue to test positive for COVID-19, even after you recover?
Our Verify team broke that question down into two parts to try and seek answers. First, can a COVID-19 patient test positive days or months later? Second, if so, does that mean they are still contagious?
Our Verify sources include the Centers for Disease Control and Prevention, a study from the Korea Disease Control and Prevention Agency, and Dr. Stuart Ray at Johns Hopkins.
In August, the CDC said that those who tested positive can continue to test positive for 90 days.
"At this time, we have limited information about reinfections with the virus that causes COVID-19," the CDC wrote online. "This is a new virus, and CDC is actively working to learn more. We will provide updates as they become available. Data to date show that a person who has had and recovered from COVID-19 may have low levels of virus in their bodies for up to 3 months after diagnosis. This means that if the person who has recovered from COVID-19 is retested within 3 months of initial infection, they may continue to have a positive test result, even though they are not spreading COVID-19."
That statement is backed up by a study out of the Korea Disease Control and Prevention Agency, previously called the Korea Centers for Disease Control and Prevention, which researches infectious diseases.
They studied 285 cases, where the patient continued to test positive after being discharged.
So we can Verify that yes, a person can continue to test positive for COVID-19 weeks after recovering.
But can that person still spread COVID-19?
In that study out of South Korea, researchers contacted 790 people who had been in contact with those who tested positive, and only three new cases emerged.
Researchers also point out those people had contact with other people who tested positive.
"Other than their exposure to the re-positive cases during their respective re-positive period, all of the three newly confirmed cases had history of contact with Shincheonji religious group or a confirmed case in their family," researchers wrote.
Later in the study researchers conclude, "no case was found that was newly infected solely from contact with re-positive cases during the re-positive period."
Our Verify team also spoke with Dr. Stuart Ray, an infectious disease specialist from Johns Hopkins.
"We have these longitudinal cohorts where we test them repeatedly, and we have some people in our cohort at Johns Hopkins who have been testing positive for over 100 days, so we know that people could test positive for long periods of time and we don't understand what that means," Ray said. "We don't have evidence that those people are infectious at that point, but we don't have a way to prove they're not infectious.”
So, while someone can test positive for COVID19 weeks or months after recovery, experts are still looking at data to determine if they are infectious.