CHINESE researchers say they may have discovered a new mutation of the coronavirus in an infected patient who carried the disease for 49 days.
The rare case was observed in a middle-aged man who tested positive for COVID-19 for a record length of time with a chronic and “prolonged infective ability”, docs said.
The man was found to have “low toxicity”, or non-severe and only mild symptoms, but a prolonged ability to infect others, the scientists reported.
The study was conducted by researchers at the Army Medical University in Chongqing, No 967 Hospital of PLA, Dalian, and General Hospital of the PLA Central Theatre Command in Wuhan.
Findings were published on March 27 on MedRxiv, a pre-print website for unpublished preliminary reports of scientific medical papers yet to be peer reviewed and not to be taken as a guide for clinical practice.
‘CHRONIC INFECTED PATIENTS’
The chronic case indicates the possibility of a strain which can spread among people for weeks, even if the host doesn’t show many symptoms.
The researchers warn there may be more “chronic infected patients” who carry the infection into their surroundings and trigger an outbreak.
The paper reads: “Prolonged viral shedding is associated with severe status and poor prognosis of COVID-19 patients. “Unexpectedly, here we report a non-severe patient with the longest duration of viral shedding.”
Researchers conclude that the virus sub-style “might have a low toxicity and transmissibility, but have a prolonged infective ability”, adding it was “hardly to be eliminated in the body with regular therapy”.
The patient required an injected of plasma from a COVID-19 survivor in order to recover, they said.
Although the man was observed to have a high Covid-19 viral load, his immune cell indicators remained stable, indicating to researchers that the virus and the host may have formed a “symbiotic relationship”.
HARDER TO CURE
The Chinese man, who has not been named, visited a hospital in Wuhan to be tested on February 8, 2020.
He stated that he had suffered an intermittent low fever, but had no other typical Covid-19 symptoms, such as a cough, chill, shortness of breath.
Swabs tested positive on days 17, 22, 26, 30, 34, 39, 43 and 49.
More concerningly, the man had been “shedding”, or excreting the disease to others, with a consistently high viral load similar to those of severe or critical cases, without displaying the usually associated symptoms, the experts said.
Previous clinical observation has shown the median time of surviving patients carrying the disease before recovering to be 20 days.
One of the man’s elderly female relatives also tested positive for COVID-19, with moderate symptoms but reportedly recovered quicker than average for her age.
The newly discovered mild sub-type displayed lower toxicity, is not as infectious, but proved harder to eliminate and could affect both the young and the old.
The longer the duration of shedding, the more severe the outcomes tend to be, Dr Li Tan and colleagues said.
“Interestingly, contrary to the conclusions above, we here reported one of the non-severe cases has the longest duration of viral shedding,” the team said, as reported by MailkOnline.
Researchers have previously discussed the possibility of two major types of SARS-CoV-2, namely L subtype and S subtype.
L type is more prevalent consisting of approximately 70 per cent in all patients and is more likely to spread than S type, Chinese researchers found.
Dr Tan and colleagues added: “We cannot assure that Case 1-associated virus belongs to S type, mutated L type or a new subtype.
‘We cannot exclude an original new subtype that was not identified.”
Earlier this week, Britain’s youngest coronavirus victim, 13, died from the disease just one week after first developing symptoms.
Ismail Mohamed Abdulwahab died in King’s College Hospital in London on Monday after testing positive for the deadly disease.
