The study highlights the risk of the covid-19 mutation in immunosuppressed humans

An English patient lingered with Sars-CoV-2 in the body for 16 months until he died, European researchers revealed. The study highlights the risk of coronavirus mutation in people with impaired immune responses, such as transplant recipients and those receiving cancer treatment.

Researchers revealed the longest period of Sars-CoV-2 infection yesterday. An immunosuppressed English patient had a positive covid-19 test for 16 months until he died as a result of the disease. Details of the case were published in a study that also assessed the genetic mutations suffered by the pathogen in a group of individuals with deficiencies in the body’s defense system. The article will be presented in its entirety in the next edition of the European Congress of Microbiology and Infectious Diseases, which begins today in Lisbon, Portugal.

The patient, whose identity has not been disclosed, was positive for the first time in mid-2020 and had difficulty breathing. The evaluator continued with the same results in all observational analyzes (approximately 45) conducted until his death, 505 days later, revealed France-Presse news agency Gaia Nebbia, co-author of the study and a researcher at Guy’s and St Thomas. Hospital. , In the United Kingdom. According to the researcher, the longest case of infection (confirmed by PCR) was previously 335 days.

In the same study, experts analyzed eight other immunosuppressed individuals with persistent viral infection. All were diagnosed between March 2020 and December 2021. The aim of the researchers was to look at the possible genetic changes in Sars-CoV-2 in the body of these patients. . “One theory floating in the field of infectology is that viral variants develop in people whose immune systems are weakened by an illness or drug treatments such as chemotherapy,” explained Luke Blagdon Snell, a researcher at the English Medical Center and another author. research. “We wanted to investigate what mutations occur and how they develop in these groups with ongoing infection,” he added.

All subjects analyzed in the study were positive for at least eight weeks. The cases lasted an average of 73 days, but two patients had a prolonged infection for more than a year. The group evaluated had a weakened immune system due to various factors such as transplantation, HIV, cancer, or other illnesses. Using regular viral genetic analyzes, the researchers found that five of the nine people developed at least one mutation in the worrisome variants of the pathogen, such as alpha, delta, and omicron variants, some of which had multiple changes in the microorganism. “These data provide very relevant evidence because they support the idea that new virus strains can develop in immunocompromised individuals,” Snell explained. “However, it is important to note that none of the individuals evaluated in our work developed mutations that would alter a worrying variant of the strain,” he added.

The researchers explained in the study that five of the nine patients survived. Of this group, two evaluated recovered without treatment, two got rid of the disease with antibodies and antiviral drugs, and one of the individuals remains infected. “At his last follow-up in early 2022, this patient had been infected for more than a year (412 days).

Hidden

In the article, experts also report one of the first cases of “hidden infection” of Covid-19. “The term describes a patient who is believed to have removed the virus, for example, by negative tests, but who later finds persistent infection, symptoms, and positive PCR months after this ‘pseudo’ treatment,” Snell explained. This phenomenon has also been observed in other viral diseases, such as ebola or hepatitis B, according to researchers. A hidden infection is also different from a long covid, where the pathogen is no longer in the body but the symptoms. continue.

According to the authors, the data seen in the study suggest that individuals with defects in the immune system should be the subject of more scientific studies of covid-19. The researchers believe it is necessary to better understand the effect of the new coronavirus on the body of these patients and to develop more treatment options for the group. “In immunocompromised patients with a persistent infection, the results are poor and new treatment strategies are urgently needed to eradicate the infection. Based on our research, we see that these measures can also prevent the emergence of new variants.

A new test could predict clinical development

A study presented at the European Congress of Clinical Microbiology and Infectious Diseases also reveals that exaggerated cytokine activity – an irregular reaction of the immune system – may in the past refer to covid-19 patients with poorer prognosis. In the study, researchers explain that this phenomenon triggers harmful inflammation that can lead to organ failure and death.

The researchers came to this conclusion after evaluating 415 patients with a mean age of 70 years with a mild, moderate, and severe form of the disease between May 2020 and March 2021. found that people with more complications had higher cytokine activity from the first days when they arrived at medical centers.

Experts do not yet know which of these molecules are responsible for patients’ worsening, but they believe that if levels of these cytokines can be measured in the future and tests can be used in hospital care, it is possible. identify those with a worse prognosis, in which case doctors recommend personal treatment. “Our work can help select patients with poorer prognosis who need to go into intensive care, and potentially help identify their treatment,” said Emanuela Sozio, a researcher at the Azienda Sanitaria Universitaria infectious disease clinic. Friuli Centrale, Italy, and one of the authors of the study.

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