Around 51 patients who recovered from coronavirus tested positive for the second time in South Korea. The patients, from the city of Daegu, had all spent time in quarantine while recovering from the virus, but were diagnosed again just days after being released.
South Korea has been among the most successful countries in the world in tackling the virus, using strict quarantining measures as well as meticulous testing and tracking of the virus.
It has resulted in the number of new cases being at a record low, with levels now similar to those at the beginning of February when the pandemic had not yet picked up speed.
The fresh 51 patients were identified as part of a study carried out in Daegu, the epicentre of the South Korean outbreak, by a team of epidemiologists from the Centers for Disease Control and Prevention.
Interestingly, the researchers say it didn’t seem as though the patients had be reinfected, but that the virus had remained in their cells at undetectable levels, later “reactivating”.
The claim runs contrary to evidence currently available and to hopes of immunity after infection.
Speaking to MailOnline, Paul Hunter, an infectious diseases professor at the University of East Anglia, said: “I agree that these will not be reinfections but I do not think these will be reactivations.
“Personally I think the most likely explanation is that the clearance samples were false negative.”
In order to be allowed to leave quarantine, patients are typically required to test negative twice.
There is much more evidence needed to be collected before conclusions are drawn regarding this.
Speaking in February, Mark Harris, Professor of Virology at the University of Leeds, said: “Clearly we need more information about these patients, such as were there underlying medical conditions or a change in circumstances that might have allowed the virus to escape immune control?
“This highlights the need for more research into the biology of the new coronavirus.
“It is very much early days in our efforts to understand it.”
There are currently over 50,000 confirmed cases of the virus in the UK.
Meanwhile, 5,373 people have died.
On Monday, Prime Minister Boris Johnson was taken into intensive care after his coronavirus symptoms became considerably worse.
Mr Johnson tested positive for the virus mid-way through March, and was finally admitted to St Thomas’ Hospital in London on Sunday after his fever persisted past his ten days spent in isolation.
Earlier on Monday he tweeted from hospital: “Last night, on the advice of my doctor, I went into hospital for some routine tests as I’m still experiencing coronavirus symptoms.
“I’m in good spirits and keeping in touch with my team, as we work together to fight this virus and keep everyone safe.
“I’d like to say thank you to all the brilliant NHS staff taking care of me and others in this difficult time.
“You are the best of Britain.”