A recent study, published in the journal Cell, revealed an unusual case of a blood cancer patient who carried coronavirus for about 105 days and remained infectious for nearly 70 days, without experiencing any symptoms the entire time. Most people infected with the deadly virus actively shed the pathogen for eight days, however, in this case, as a woman from Washington had been infected very early in the pandemic and had numerous positive PCR tests for the virus over a period of weeks. The scientists said that understanding how long people can remain actively infected is important since it provides new details about COVID-19 that are still not well understood.
The study’s senior author Vincent Munster, a virologist at the National Institute of Allergy and Infectious Diseases in the US said, “At the time we started this study, we really didn’t know much about the duration of virus shedding. 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”.
According to the research, the woman, who is 71-year-old, was immunocompromised due to chronic blood cancer but never showed any symptoms of the deadly virus. The researchers said that she was found to be infected with the virus when she was screened after being admitted to the hospital for severe anaemia. It was later that her doctors recognised that she had been a resident of a rehabilitation facility experiencing a large outbreak.
After the researchers studied samples and regularly collected data, they discovered 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. Muster said that the case was something that the doctors expected might happen, but it had never been reported before. The scientists believe that the patient remained infectious for so long because her compromised immune system never allowed her to mount a response.
‘Longest case’ of being actively infected with COVID
The researchers found from the blood tests that the 71-year-old’s body was never able to make antibodies. The scientists said that even treatment with antibodies from recovered COVID-19 patients had little effect on her health. Despite the inability to mount an antibody response, the woman, however, never went on to develop COVID-19. When she was examined to see how the virus might have changed over the course of the time, the researchers found that the samples collected from her at various times displayed different dominant gene variants of the virus.
However, the researchers believe that the mutations did not play a role in how long the virus persisted since they saw no evidence of the pathogen. Munster said that this case could be the “longest case” of anyone being actively infected with the deadly virus while remaining asymptomatic.
He said, “We’ve seen similar cases with influenza and with Middle East respiratory syndrome, which is also caused by a coronavirus. We expect to see more reports like ours coming out in the future”.