A Dutch pensioner suffered the longest Covid infection ever recorded: 613 days.
While most people can expect to get rid of the virus within days or weeks, the 72-year-old man had a weakened immune system and ultimately died from the infection.
According to scientists, the virus mutated about 50 times and finally generated an ultramutated variant.
They warned that these cases are perfect breeding grounds for new deadly strains of the disease to develop.
However, separate NHS data published today shows that Covid cases in hospital are also rising, up by more than a third in the last four weeks. There were 3,390 virus patients in hospital on December 17, 38 percent more than the 2,452 recorded on November 19. This is also a 12 percent increase in one week from the 3,024 recorded on December 10.
The patient was admitted to the Amsterdam University Medical Center in February 2022 with the omicron variant of Covid.
He had a history of blood cancer and had received treatment that depleted B cells, including those that normally produce Covid-targeted antibodies.
Despite receiving several Covid vaccines, he had little antibody response when tested upon admission to hospital and did not respond to antibody treatments.
But the researchers found that the virus developed a mutation resistant to sotrovimab as soon as 21 days after receiving the antibody.
They also noted that the development of anti-spike antibodies in the first month was minimal, indicating that the patient’s immune system was unable to eliminate the virus.
Prolonged infection led to the emergence of a new, immunoevasive variant of the virus due to its extensive evolution within a host. He eventually died from a relapse of a disease in his blood.
Presenting their findings at the ESCMID Global Congress in Barcelona next week, the researchers said he had remained Covid positive, with high viral loads, for a total of 613 days.
The mutated variant was not transmitted to anyone else, they confirmed.
Dr Magda Vergouwe, from the Center for Experimental and Molecular Medicine (CEMM) in Amsterdam, warned that the case underlines the importance of tracking infections in the most vulnerable patients, whose bodies could be used as hosts to develop resistant mutations.
She said: “This case highlights the risk of persistent SARS-CoV-2 infections in immunocompromised people, as unique SARS-CoV-2 viral variants may arise due to extensive intra-host evolution.
“We emphasize the importance of continuing genomic surveillance of the evolution of SARS-CoV-2 in immunocompromised people with persistent infections, given the potential threat to public health from the possible introduction of viral escape variants into the community.”
He recognized that there had to be a balance between protecting the world from dangerous new variants and providing humane and supportive end-of-life care to seriously ill patients.
Before this case, UK doctors believed they had documented the longest recorded Covid infection in someone they treated for more than 16 months, or 505 days.
Doctors at King’s College London and Guy’s and St Thomas’ NHS Foundation Trust said detailed laboratory analysis of the unnamed patient revealed it was the same persistent infection, rather than repeated episodes.
Dr Vergouwe added that although there is an increased risk of developing new variants in immunocompromised patients, not all variants that develop will be of public interest.
The underlying mechanisms involved in the development of a variant of concern are much more complex, as they also depend on factors in the population surrounding the patient, including the prevalence of B- and T-cell-related immunity.
He added: “The duration of SARS-CoV-2 infection in this described case is extreme, but prolonged infections in immunocompromised patients are much more common compared to the general community.”
‘Further work by our team includes the description of a cohort of long-term infections in immunocompromised patients at our hospital with durations of infection ranging from one month to two years.
“However, from the point of view of the general public, long-term infections remain rare, as the immunocompromised population represents only a very small percentage of the total population.”