New coronavirus sub-type may have caused 49-day long illness found in infected man showing mild symptoms
One COVID-19 patient in China has caught the attention of Chinese health experts. For the first time, they have recorded a case of a patient, a middle-aged man, staying sick for 49 days. During this period, the man developed a mild disease, potentially staying infectious, according to scientists.
This led them to suspect that the man was infected with a mutated version or a sub-type of the new coronavirus. The experts have published their findings in a preprint study.
"The virus and the host may even form a symbiotic relationship," said the researchers from the Army Medical University in Chongqing, No 967 Hospital of PLA, Dalian, and General Hospital of the PLA Central Theatre Command in Wuhan.
Early evidence suggests that only people with a severe disease stay infectious for a long period. But the Chinese man is an outlier: he had a mild form of the disease and yet stayed infectious for a long time.
The team, however, has not provided evidence to confirm whether the virus was a new sub-type or if it belonged to the already known sub-types: S-type or L-type.
S- and L-sub-types of the virus are a result of mutations, which is common among viruses. Mutations do more than just providing a survival advantage to organisms and some are even capable of wiping out organisms.
But mutations in coronavirus have not reached a pace where it alters its functioning, say experts. The 'S' and 'L' types only differ by two mutations and are 99.993% identical.
The study
The Chinese man who was down with fever for around one week, reportedly got himself tested on February 8, 2020. He had no other common symptoms such as a cough, the authors wrote.
The team tested him for signs of the virus on days 17, 22, 26, 30, 34, 39, 43, 47 and 49. His results came back positive on all days, barring day 47. This could be due to some error during testing or processing.
This led the team to believe the patient was shedding the virus or stayed infectious for 49 days. This is unusual because people have been shown to stay infectious for up to 37 days.
To gain more insights on the virus and whether it is a new subtype, the experts will continue sequencing studies.
The study adds that the patient may have passed on the virus to a close relative: an elderly woman. This woman also had mild disease, despite having an underlying health condition. She, however, was reported to have cleared the virus within 16 days.
To treat the man, the team tried a different approach with help from recovered patients. More specifically, doctors are using the blood of coronavirus survivors to treat patients. From the blood, the experts extract the body's natural weapons against the virus: antibodies. These antibodies will help sick patients fight the disease.
The treatment seemed to have worked on the man, "implying this method might be a potent treatment for patients with COVID-19. However, the long-term outcomes and complications should be further investigated," they wrote.