US cancer patient carried coronavirus for 105 days without symptoms, study finds

A new study has revealed that a blood cancer patient in the US carried the coronavirus for about 105 days, and "remained infectious for at least 70," without experiencing any symptoms of the deadly viral disease.

It is to be noted that the majority of coronavirus-infected patients shed the pathogen for about 8 days.

According to the study published in the journal Cell, understanding how long people can remain actively infected is important since it provides new details about COVID-19 that are still not well understood.

"At the time we started this study, we really didn't know much about the duration of virus shedding," said senior author of the study Vincent Munster, a virologist at the National Institute of Allergy and Infectious Diseases in the US.

"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 said.

The study noted that the patient from Kirkland, Washington, had contracted COVID-19 very early during the pandemic and had numerous positive PCR tests for the virus over a period of weeks.

The 71-year-old woman, according to the research, was immunocompromised due to chronic blood cancer but never showed any symptoms of COVID-19.

The woman was found to be COVID-19 positive when she was tested after being admitted to a hospital for severe anemia. Her doctors recognised that she had been a resident of a rehabilitation facility experiencing a large outbreak.

As the researchers studied samples that were regularly collected from the patient's upper respiratory tract, they found that the infectious virus continued to be present for at least 70 days after the first positive test, and the woman didn't fully clear the virus until after day 105.

"This was something that we expected might happen, but it had never been reported before," Munster said.

As per the researchers, the patient remained infectious for so long because her compromised immune system never allowed her to mount a response. The researchers, from blood tests, found that the woman's body was never able to make antibodies

According to scientists, even treatment with antibodies from recovered COVID-19 patients had little effect on her health.

Despite her inability to mount an antibody response, she never went on to develop COVID-19, they added.

According to Munster, this could be the longest case of anyone being actively infected with the coronavirus while remaining asymptomatic.