A woman carrying the COVID-19 coronavirus in Washington state shed infectious virus particles for 70 days — wildly contagious the whole time despite exhibiting no symptoms whatsoever of the disease, according to a new study published in the journal Cell.
Woman shed coronavirus particles for 70 days with no symptoms
The woman is 71 years old and had a type of leukemia — a cancer of the white blood cells — which left her immune system in a weakened state, less capable of clearing her body of the coronavirus. While researchers have wondered whether people with weakened immune systems might be contagious for longer periods than are typical, there was scant real-world evidence of this happening.
Coronavirus reaching people with immune disorders
Notably, these latest findings contradict guidelines from the Centers for Disease Control and Prevention (CDC), which claim immunocompromised people with COVID-19 will likely not be infectious after 20 days.
The new study suggests "long-term shedding of infectious virus may be a concern in certain immunocompromised patients," wrote the authors in the paper, published on Wednesday.
"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," said Vincent Munster, senior study author and virologist at the National Institute of Allergy and Infectious Diseases, in a statement.
Atypical asymptomatic coronavirus case
The woman initially contracted the coronavirus late in February, amid the country's early reports of a serious outbreak of COVID-19 — which occurred at the Life Care Center rehabilitation facility in Kirkland, Washington — where she was a patient.
She was initially hospitalized for anemia associated with her cancer on Feb. 25 — which is when doctors screened her for COVID-19, since she came from the center with the initial outbreak, reports Live Science. On March 2, she tested positive.
For the next 15 weeks, the woman was tested for the illness more than a dozen times. It was detected in her upper respiratory tract for 105 days — with infectious coronavirus particles continually detected for at least 70 days.
Woman's body never made full COVID-19 immune response
The researchers in the study successfully isolated the virus from the patient's samples, and grew it in a lab — which allowed them to capture images of the virus with scanning and transmission electron microscopy.
People infected with COVID-19 are typically contagious for roughly eight days after contracting the illness, according to the report. In the past, the longest duration of infectious virus shedding in a COVID-19 patient was a mere 20 days, Live Science reports.
This woman was probably contagious for so long because her body never mounted a full immune response. In fact, her blood samples didn't show the presence of any antibodies against the virus.
Compromised immune system should have seen severe COVID-19, but didn't
She was treated with two rounds of convalescent plasma — which is blood from recovered COVID-19 patients rich in antibodies capable of fighting off the disease. After the second treatment, she cleared the infection out of her system — but there's no way to know with certainty whether the convalescent plasma helped, since she still had low antibody concentrations following the transfusion.
As of writing, the researchers don't know why the woman remained asymptomatic despite her immunocompromised condition during COVID-19 infection — which according to the CDC should have put her at higher risk of a severe case.
"You would indeed think that the immunocompromised status would allow the virus to spread from the upper (more common cold scenario) to the lower respiratory tract (pneumonia)," said Munster to Live Science, in an email. "Even though the patient was at least infected for 105 days, this clearly didn't happen, and this remains a mystery to us."
While the COVID-19 coronavirus begins what many officials expect to be a second wave in cities like New York, new evidence is constantly surfacing of the capacities of this devastating pandemic. The thought of a person feeling fine but remaining infectious for 70 days is daunting, to say the least, but hopefully one of the best vaccine candidates will finally put this disease to rest.
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