UK patient had Covid for 505 days straight, study shows

AP

London, April 22

A UK patient with a severely weakened immune system had Covid for almost a year and a half, scientists reported, underscoring the importance of protecting vulnerable people from the coronavirus.

There's no way to know for sure whether it was the longest-lasting Covid infection because not everyone gets tested, especially on a regular basis like this case.

But at 505 days, “it certainly seems to be the longest reported infection," said Luke Blagdon Snell, an infectious disease expert at the Guy's and St Thomas' NHS Foundation Trust.

Snell's team plans to present several “persistent” Covid cases at an infectious diseases meeting in Portugal this weekend.

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. None were identified for privacy reasons.

Repeated tests showed their infections lingered for an average of 73 days. Two had the virus for more than a year. Previously, researchers said, the longest-known case that was confirmed with a PCR test lasted 335 days.

Persistent Covid is rare and different from long Covid.

"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 more than once. Still, genetic sequencing showed that the virus changed over time, mutating as it adapted.

Researchers hope more treatments will be developed to help people with persistent infections beat the virus.

“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.

Although persistent infections are rare, experts said there are many people with compromised immune systems who remain at risk of severe Covid and who are trying to stay safe after governments lifted restrictions and masks started coming off.