In a bizarre incident, a U.K. patient with a significantly compromised immune system remained Covid-19 positive for almost a year and a half, scientists reported.
Scientifically, it is impossible to infer whether this was the longest-lasting case of Covid-19 infection ever as not everyone gets tested on a regular basis.
But according to Dr. Luke Blagdon Snell, an infectious disease expert at the Guy’s & St. Thomas' NHS Foundation Trust, this one certainly seems to be the longest reported infection.
Dr Snell and his team conducted a research involving nine patients who reported long-term infections and they are planning to present the report at an infectious diseases meeting in Portugal this weekend.
What is 'Persistent Covid'?
Science shows distinct differences between 'Persistent Covid-19' and 'Long Covis-19'.
According to Dr. Luke Blagdon Snell, in long Covid, it’s generally assumed the virus has been cleared from your body but the symptoms persist while with persistent infection, it represents ongoing, active replication of the virus.
Whom did the scientists carry the research on?
The study involved nine patients with super long infections and it emphasized on the various types of mutations that arose during the course of testing positive and it also investigated the possibility of the emergence of other new variants. The concerned patients tested positive for the virus for at least eight weeks and each of them had medical histories including organ transplants, HIV, cancer or treatment for other illnesses which eventually resulted into severely compromised immune systems.
As per the daily test results, their infections lingered for an average of 73 days for all of them while two acted as the host for the virus for more than a year. Before this, according to the researchers, the longest-known case that was confirmed with a PCR test which lasted 335 days.
What were the findings?
Each time researchers tested patients, they analyzed 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 changed over time, mutating as it adapted.
The mutations were similar to the ones that later showed up in widespread variants, Snell said, although none of the patients spawned new mutants that became variants of concern. There's also no evidence they spread the virus to others.
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.
“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-19 and who are trying to stay safe after governments lifted restrictions and masks started coming off. And it's not always easy to know who they are, said Dr. Wesley Long, a pathologist at Houston Methodist in Texas, who was not part of the research.
“Masking in crowds is a considerate thing to do and a way we can protect others,” he said.
(With AP inputs)