UK patient for 505 straight days tests positive for Covid-19 as longest-lasting reported case
For more than 500 days, a UK patient with a severely weakened immune system had Covid-19 as reported by scientists.
It was the longest-lasting Covid-19 infection that has been reported. At 505 days, “It certainly seems to be the longest reported infection,” said Dr Luke Blagdon Snell, an infectious disease expert at the Guy’s & St. Thomas’ National Health Service (NHS) Foundation Trust.
Previously, researchers said, the longest-known case that was confirmed with a PCR test lasted 335 days.
Snell’s team will be attending a diseases meeting in Portugal this weekend, where they plan to present several persistent Covid-19 cases.
Their study investigated which mutations arise — and whether variants evolve — in people with super long infections. It involved nine patients who tested positive for the virus for at least eight weeks. All had weakened immune systems from organ transplants, HIV, cancer or treatment for other illnesses.
Repeated tests showed that their infections lasted for an average of 73 days. Two of them had the virus for more than a year.
“In long Covid, it’s generally assumed the virus has been cleared from your body but the symptoms persist,” Snell said. “With persistent infection, it represents ongoing, active replication of the virus.”
Each time researchers tested patients, they analysed the genetic code of the virus to make sure it was the same strain and that people didn’t get Covid-19 more than once. Still, genetic sequencing showed that the virus was mutating as it adapted and changed over time.
Although none of the patients spawned new mutants that became variants of concern, the mutations were similar to ones that later showed up in widespread variants, said Snell.
The person with the longest known infection tested positive in early 2020, was treated with the antiviral drug, remdesiver, and died sometime in 2021. Researchers declined to name the cause of death and said the person had several other illnesses.
Five patients survived. Two cleared the infection without treatment, two cleared it after treatment and one still has Covid-19. At the last follow-up earlier this year, that patient’s infection had lasted 412 days.
Researchers hope more treatments will be developed to help people with persistent infections beat the virus. Although persistent infections are rare, experts say there are many people with compromised immune systems who remain at risk of severe Covid-19 and who are trying to stay safe after governments lifted restrictions and masks started coming off.
“We do need to be mindful that there are some people who are more susceptible to these problems like persistent infection and severe disease,” Snell said.
“Masking in crowds is a considerate thing to do and a way we can protect others,” he said.