Documented the longest Sars-CoV-2 infection ever: lasting 505 days, it gripped an immunosuppressed patient, who then did not make it despite the therapies. Presented in Lisbon at the congress of the European Society of Clinical Microbiology and Infectious Diseases by experts from King’s College London and the Guy’s and St Thomas’ NHS Foundation Trust, the case report reinforces the idea that new covid variants were formed precisely in these patients who fail to heal.
The previous record
Just under a year and a half, only to be defeated. Also breaking the previous record, that of an immunocompromised 48-year-old woman with type 2 diabetes and large B cell lymphoma behind her, who remained positive for 335 days. Beyond the extraordinarily extended durations, these cases pose a problem: that of understanding how the virus changes while harboring in people with “deactivated” immune systems. Scientists have studied 9 Covid patients in London and provide evidence that new variants of the virus can arise in the “eternal positives”, immunocompromised who fail to eradicate the enemy.
Crucial indications from the study
Sars-CoV-2 had mutated in 5 of the cases analyzed and in one patient contained “10 mutations that would have arisen separately in variants of concern such as Alpha, Gamma and Omicron,” the experts report in the note. The authors of the study present the results of their analysis at the Eccmid 2022 congress, scheduled for April 23 to 26, and also illustrated the details of one of the first occult infections from Covid: cases, that is, in which it was thought that the patient had cleared the virus, with a negative test to confirm, but later it turns out that he had the infection in progress. “We wanted to investigate what mutations occur and whether the variants evolve in these persistently infected people,” explains Luke Blagdon Snell, of Guy’s and St Thomas’ Nhs Foundation Trust, first author of the study.
Concurrent illness or medical treatment
During the pandemic, as we have seen, multiple new Sars-CoV-2 mutants emerged. «Some of these variants – observes the expert – are transmitted more easily, cause more serious diseases or make vaccines less effective. One theory is that they evolve in people whose immune systems are weakened by disease or medical treatments such as chemotherapy, who may have a prolonged SARS-CoV-2 infection. ‘
The development of multiple mutations
The 9 immunocompromised patients involved in the study tested positive for the virus for at least 8 weeks. The infections persisted for an average of 73 days, but 2 of them remained positive for more than a year. The cases were studied between March 2020 and December 2021. In detail, they were people who had weakened immune systems due to organ transplants, HIV infections, cancer or medical treatments for other diseases. Regular sampling and genetic analysis of the virus showed that 5 patients developed at least one mutation observed in the variants of concern. Some have developed multiple mutations associated with variants such as Alpha, Delta and Omicron. Among them, the case of the patient whose virus contained 10 mutations then separately detected in the variants Alpha, Gamma and Omicron. “This provides evidence that the mutations found in the variants of concern arise in immunocompromised patients – remark Snell and colleagues – Evidence that supports the idea that new viral variants can develop” in people with these characteristics. “It is important to note, however, that none of the patients involved in our work developed any new variants that subsequently became variants of widespread concern,” the authors point out. Furthermore, “while this study shows that variants could arise in the immunocompromised, it remains unknown whether the variants of concern” that have become dominant from time to time, “such as Alpha, Delta and Omicron, have arisen in this way.”