Positive for 411 days, a patient finally cured by doctors

The time must have seemed very long to him. A 59-year-old man, with a weakened immune system from a kidney transplant, contracted Covid-19 in December 2020 and remained positive… until January 2022, i.e. for 411 days. In a study published in the journal Clinical Infectious Diseases, a team of British researchers led by Luke Blagdon Snell details how this man finally overcame his infection.

A persistent infection, different from a long Covid or repeated episodes of the disease, can strike a small number of patients with already weakened immune systems. They can test positive for months or even years, with the infection “rumbling all the time”, says Dr Snell, an infectious disease specialist at the Guy and St Thomas Foundation of Britain’s public health service, the NHS.

The new, more resistant variants

To find out if the patient in question had been contaminated several times or if he had a persistent infection, the researchers used rapid genetic analysis (nanopore sequencing). The results proved infection. So the researchers administered a combination of monoclonal antibodies, casirivimab and imdevimab, which apparently worked.

But this success is linked to the fact that the patient was infected with an old version of the coronavirus. This variant, dominant in late 2020, has since been superseded by other incarnations. However, “the new variants (…) are resistant to all the antibodies available in the United Kingdom, in the EU, and even in the United States”, notes Luke Blagdon Snell. In April, these same researchers announced, at the European Congress of Microbiology and Infectious Diseases, the longest known persistent infection with Covid-19, in a man who tested positive for 505 days, until his death.