Persistent Covid infection, which is different from long Covid occurs in a small number of patients. These patients can test positive for months or even years.

Report of NHS foundation, London

The infection can pose a serious threat because half of the patients also have persistent symptoms such as lung inflammation, said Luke Snell, a physician specializing in infectious diseases at Guy's and St Thomas' NHS Foundation Trust and King's College, London.

He described how a 59-year-old man overcame his infection after more than thirteen months. The man, who has a weakened immune system due to a Kidney transplant, caught Covid in December 2020 and tested positive until January this year.

The man had an early B.1 variant which was dominant in late 2020. The researchers gave him a combination of Casirivimab and Imdevimab Monoclonal antibodies from Regeneron.

The treatment is no longer widely used as it is ineffective against newer variants. But it successfully cured the man.

The researchers used several such treatments to try to save a seriously ill 60-year-old man in August this year who has been infected since April.

Paxlovid and Remdesivir

The team crushed up two anti-viral treatments not previously used together- Paxlovid and Remdesivir and administrated them. "Miraculously he cleared and this is the avenue for how we treat these very difficult persistent infections," Snell said.

At a conference in April, the team announced the longest-known persistent infection in a man who tested positive for 505 days before his death.

The research team is coming up with newer infections every day. Their fight continues as they have been working on the topic for a long period, and managed to know about these type of viruses which was unknown to science even. A community of researchers around the globe is trying to find a way to fight this brutal infection and its different symptoms.