Scientists may have found mutated coronavirus sub-type which lasts 49 days

People could be going around with 'chronic cases' for much longer than expected.

Researchers from China claim to have discovered a new type of Covid-19 after a patient was left infectious for an unprecedented 49 days.

They say the middle aged man who had it needed to be injected with the blood of a coronavirus survivor in order to recover, suggesting the new strain is much harder for the body to fight off. His symptoms were mild and scientists say his body had struck a ‘dynamic balance’ with the bug.

A study on the case was published on March 27 on the medRxiv site for medical papers and is yet to be scrutinised or peer reviewed by other scientists. Covid-19 swab tests showed that for 49 days, the unnamed Chinese patient had been ‘shedding’ meaning the bug was being carried in his breath through droplets.

The average for coronavirus shedding is thought to be 20 days with the longest case recorded at 37 days. As symptoms, scientists warn ‘chronic cases’ like the one documented last week show how long someone could spread the disease without being treated.

The unnamed Chinese patient went to hospital in Wuhan for tests on February 8 after suffering from an intermittent fever for a week but had no other symptoms associated with Covid-19, such as a cough.

He also had some infection lesions on his lungs which went away not long after being taken in for medical treatment.

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The patient had a high Covid-19 viral load but his immune cell indicators remained stable. Researchers from the Army Medical University in Chongqing said: ‘The virus and the host may even form a symbiotic relationship,’

Using blood-based therapy used in China and experimentally in the UK and US, doctors pumped the patient with plasma from someone who had recovered from Covid-19 and had developed antibodies to the disease.

According to reports, an elderly relative had also tested positive for the disease and recovered faster than most people of her age. Researchers said this too points towards a milder sub-type of SARS-CoV-2 (Covid-19).

They suggest it is not as toxic and less infectious but is much harder to eliminate. Ir has already been suggested that could be two main sub-types of the novel coronavirus.

Around 70% of cases would be caused by the L type, which spreads more easily than the S type.

Researcher Dr Li Tan said: ‘We cannot exclude an original new subtype that was not identified.’

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