After the new coronavirus variant was reported in the UK, Guangdong CDC strengthened the gene sequencing analysis of imported cases of new coronavirus, and carried out retrospective gene sequencing analysis of samples of confirmed cases and asymptomatic infected persons imported from abroad in our province since September last year. A novel coronavirus pneumonia strain was found in a throat swab sample of a confirmed case of new crown pneumonia in Guangdong in January 2, 2021. It is highly similar to that reported recently in the UK by B.1.1.7.
The case is an 18-year-old Chinese overseas student, a British immigrant under closed-loop management. On December 4, 2020, he entered Guangzhou from the United Kingdom, and the nucleic acid of the new coronavirus was negative. On December 18, samples were collected from the isolation point and tested positive for the nucleic acid of new coronavirus. They were sent to the Eighth People’s Hospital of Guangzhou City for isolation treatment. They were diagnosed as confirmed cases. The clinical classification was light. At present, they are still in the centralized medical isolation point of the Eighth People’s Hospital of Guangzhou City for medical observation after discharge.
On December 27, 2020, Guangdong CDC carried out genome sequencing analysis on throat swab samples collected from Guangzhou Eighth People’s hospital. The preliminary results showed that the b.1.1.7 mutant was identified. On January 2, high-throughput sequencing was conducted again, and the results showed that the virus gene sequence in the case belonged to b.1.1.7 subtype. The genomic sequence of the virus contains 13 branch specific amino acid mutation sites of the b.1.1.7 subtype mutant, including n501y, p681h mutation of S protein and 69-70 deletion mutation of S protein, which are potentially important for virus infection.
According to the current situation, the b.1.1.7 mutant has stronger transmission power, but the patient’s symptoms, severe illness rate and mortality rate have basically not changed. The currently developed vaccine is still effective, and the vast majority of diagnostic testing reagents are still effective, so the public need not panic.
Guangdong Province will continue to strengthen the gene sequencing analysis and monitoring of the mutant, further implement the epidemic prevention and control work in designated treatment hospitals and isolation places, further implement the health monitoring and nucleic acid detection work of the staff in isolation places, and ensure that the mutant will not cause subsequent transmission in Guangdong Province.