U.K. patient had COVID-19 for 505 days straight, study shows

Scientists say a U.K. patient with a severely weakened immune system had COVID-19 for almost a year and a half

A U.K. patient with a severely weakened immune system had COVID-19 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-19 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 Dr. Luke Blagdon Snell, an infectious disease expert at the Guy’s & St. Thomas' NHS Foundation Trust.

Dr. Snell's team plans to present several “persistent” COVID-19 cases at an infectious disease 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-19 is rare and different from long COVID-19.