More than 500 days with the covid. He lived with the Sars-CoV-2 coronavirus for 505 days, just under a year and a half, and was unable to defeat it. The patient died and his case was described by a group of UK researchers as the longest known Covid infection to date, even surpassing the previous record, that of an immunocompromised 48-year-old woman with type 2 diabetes and a large B-cell lymphoma in the back, which remained positive for 335 days. Beyond the ‘Guinness Book of Records’ duration, these cases pose a problem: that of understanding how the virus changes while harboring in people with ‘deactivated’ immune systems. Scientists from King’s College London and Guy’s and St Thomas’ Nhs Foundation Trust have studied 9 Covid patients in London and provide evidence that new variants of the virus can arise in the ‘eternal positives’, immunocompromised that fail to eradicate the enemy. 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 European Congress of Clinical Microbiology and Infectious Diseases (Eccmid 2022), scheduled in Lisbon from 23 to 26 April, and also illustrated the details of one of the first occult Covid infections. : cases, that is, in which it was thought that the patient had eliminated the virus, with negative tests to confirm, but later it is discovered 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. During the pandemic, as we have seen, multiple new Sars-CoV-2 mutants emerged. “Some of these variants – notes 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 diseases or medical treatments such as chemotherapy. who may have prolonged SARS-CoV-2 infection. “The 9 immunocompromised patients 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 – Snell and colleagues remark. which 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 variants of concern” that have become dominant from time to time, “such as Alpha, Delta and Omicron, have arisen in this way.” “Immunocompromised patients with persistent infection have poor results and new treatment strategies are urgently needed to eliminate their infection. This could also prevent the emergence of variants, “notes study co-author Gaia Nebbia. As for the patients considered in the research presented in Lisbon, 5 out of 9 survived. Two of the survivors cleared the virus without treatment, another 2 succeeded after antibody and antiviral therapies. One, on the other hand, still has the infection in progress, at the last follow-up at the beginning of 2022 he was positive for more than a year (412 days), and was treated with monoclonal antibodies to try to eliminate the infection. If at the next follow-up appointment it is positive again, it will exceed the record of 505 days of contagion of the other patient described in the study. Then there is the case of hidden infections: the researchers described a patient “symptomatic, tested positive for Covid before recovering from the disease, and then negative several times before developing symptoms again several months later”, they say. At that point the patient was once again faced with a Sars-CoV-2 positive swab and “the sequencing of the viral genome showed that the infection was caused by the Alpha variant, which has now disappeared from the UK”. This suggests that “the virus was present in the body since the initial infection, but it remained unnoticed,” the authors reason. Similar cases have been described with other viruses, such as Ebola or the hepatitis B virus. This is a case “different from long Covid – the experts point out – in which, on the other hand, it is thought that the symptoms persist even if the virus has been eliminated. from the organism “.