By Robert Preidt
MONDAY, Nov. 9, 2020 (HealthDay News) -- Most people with the new coronavirus appear to actively shed infectious virus for about eight days. But a woman in Kirkland, Wash., may have set a record, shedding the virus for at least 70 days.
The 71-year-old was infected for at least 105 days overall, but had no symptoms, according to a new report.
As far as he knows, this is the longest case of a person being infected with the new coronavirus and having no symptoms, said senior author Vincent Munster, a virologist at the U.S. National Institute of Allergy and Infectious Diseases.
"At the time we started this study, we really didn't know much about the duration of virus shedding," Munster said in a journal news release.
"As this virus continues to spread, more people with a range of immunosuppressing disorders will become infected, and it's important to understand how SARS-CoV-2 behaves in these populations," Munster explained.
Also, COVID-19 is new and not well understood, so learning more about how long people can remain actively infected can help guide public health decisions, the study authors said.
"This [type of case] was something that we expected might happen," Munster said.
Doctors discovered the woman carried the virus when she was hospitalized for severe anemia. At the hospital, she was screened for COVID-19 because she had been a resident of a rehabilitation facility experiencing an outbreak. Munster's lab in Hamilton, Mont., then began studying samples that were regularly collected from her upper respiratory tract.
The researchers found that infectious virus remained present for at least 70 days after the first positive test, and the woman didn't fully clear the virus until after day 105.
The study authors believe she remained infectious for so long because her compromised immune system couldn't combat the coronavirus. Blood tests showed that her body was never able to make antibodies against it.
The woman was treated with convalescent plasma, but it didn't have an effect because of its low concentration of antibodies, according to Munster. Convalescent plasma is antibody-rich serum from the blood of people who have recovered from an infection.
But even though the woman's immune system couldn't mount an antibody response, she never developed symptoms of COVID-19.
"We've seen similar cases with influenza and with Middle East respiratory syndrome, which is also caused by a coronavirus," Munster said. "We expect to see more reports like ours coming out in the future."
For more on COVID-19, visit the U.S. Centers for Disease Control and Prevention.
SOURCE: Cell, news release, Nov. 4, 2020