If there’s one thing we know about SARS-CoV-2, it’s that its effects on humans are different. So many, so much. When a pandemic breaks out, this coronavirus continues to bring new surprises.
A team of researchers and doctors are now reporting case one The woman with leukemia has no symptoms of COVID-19, but 70 days after the first positive test, she still spreads infectious SARS-CoV-2 particles.
This is much longer than previous reports of hospitalized adults who were found to be infected with the infectious SARS-CoV-2 virus up to 20 days after their diagnosis of COVID-19, plus Other reports of people who removed genetic material from the virus up to 63 days after they had their first symptoms. appeared.
The new report will warn doctors and public health experts of the fact that people without symptoms and weakened immune systems, such as cancer patients, seem to be able to get rid of the virus. SARS-CoV-2 for a long time. In this case, even monthly.
The research team wrote in the article describing this case: “Although it is difficult to extrapolate from one patient, our data suggest that the long-term spread of infectious virus can be a concern. in some immunocompromised patients “.
An estimated 3 million people in the US have a number of medical conditions that damage or weaken their immune systems, making them susceptible to infections. Cancer patients undergoing chemotherapy and organ transplant recipients taking immunosuppressant drugs are some examples.
Virologist and co-author Vincent Munster from the National Institute of America said: “As the virus continues to spread, more people will have a wide range of infected immunosuppressive disorders and the It is important to understand how SARS-CoV-2 behaves in these populations ”. Allergies and Infectious Diseases.
Virological researchers such as Munster will be on guard against this pandemic because of the prolonged spread of the SARS-CoV-2 virus. It has been well demonstrated that immunocompromised individuals can eliminate the usual seasonal coronavirus for several weeks after infection.
Middle Eastern Respiratory Syndrome (MERS) studies also show that immunocompromised people remove the virus that causes the disease for up to one month after infection.
But the proportion of cases of asymptomatic COVID-19 remains unclear. The danger is that people carrying this virus can easily go about their days without knowing about their ability to spread the virus.
In this case, doctors detected, isolated, and monitored a woman’s SARS-CoV-2 infection with a diagnostic PCR test and throat swab. A decade ago, a 71-year-old woman was diagnosed with chronic lymphocytic leukemia (CCL), a type of leukemia cancer that usually affects the elderly and progresses slowly.
She tested positive for SARS-CoV-2 for the first time on March 2, 2020 after being hospitalized for her cancer-related severe anemia. She then tested positive for COVID-19 13 more times and had no symptoms.
Twice she received plasma from people who had recovered from COVID-19, and finally removed the virus from her system in mid-June.
Doctors don’t know exactly when she got the coronavirus, but it’s more likely at a rehabilitation facility where there was a massive outbreak of COVID-19 in February, where the woman stayed several days earlier.
From throat swab samples collected during her 15 weeks of infection, the researchers showed that the woman had released infectious SARS-CoV-2 particles for 70 days. Some of its genetic material has also been detected 105 days after she first became positive.
We have to be careful here to differentiate between infectious viral particles and the results of a diagnostic test, which only detects fragments of viral RNA. Importantly, in this study, researchers actually isolated SARS-CoV-2 from several swab samples – including day 70 – to test whether the collected virus could be. multiplied in cells grown in a laboratory or not.
This suggests that, most likely, the virus emitted by the patient can still produce an effective infection in those exposed when it is transmitted, the researchers wrote.
In addition, when doctors were warned of the woman’s case, they quickly realized it was an opportunity to study how SARS-CoV-2 could progress during a prolonged infection such as so.
The researchers sequenced the genetic material of the virus from various samples to see how this particular type of SARS-CoV-2 virus changed while circulating in a woman. Different virus variants become more dominant at certain times, but sales are still high and not stuck.
Further experiments with the virus isolated in cells grown in the laboratory have also shown that these genetic changes do not affect the virus’s replication rate.
While these are some valuable insights, more research is still needed.
The study authors write in their paper.
And yes, this is a single case study, so we cannot give any generalizations about persistent viral growth in people with other immunodeficient conditions, or plasma nourishment. How effective the disease is to treat COVID-19, warn the study authors.
However, this is “the longest case among people who have been infected with SARS-CoV-2 actively while still having no symptoms,” according to the medical research team. They assumed the woman remained contagious for too long because her compromised immune system never allowed her to react.
“We have seen similar cases with influenza and Middle Eastern respiratory syndrome, also caused by a type of coronavirus,” said Munster. “We expect to see more reports like ours coming out in the future.”
With each, we’ll be sure to learn more about this virus, how long it lasted, and what we need to do to take care of the most vulnerable in our community.
The research is published in the journal UMBRELLA.