New Hunan Exclusive丨Hunan Disease Control has completed the sequencing of 20 new coronavirus specimens, all of which are Delta strains, which are highly homologous to Nanjing
Hunan Daily·New Hunan Client, August 2 (Reporter Zhang Chunxiang, Correspondent Zhang Yana Li Shikang) The reporter learned today that since the first local case of new coronary pneumonia in 2021 was obtained in our province on July 28, the Hunan Provincial Center for Disease Control and Prevention has Completed the sequencing of the genomes of 20 cases of Delta Covid-19.
The specimens that have completed sequencing results are all Delta strains, which are highly homologous to Nanjing.
20 samples have been sequenced in 5 days
According to Zhan Zhifei, director of the Laboratory Department of the Provincial Center for Disease Control and Prevention, genome sequencing can obtain the genome sequence information of new and unknown viruses at the first time, and has become an important tool for studying disease outbreaks.
By constructing an evolutionary tree, studying the genetic sequence changes of different patients' viruses, it can reveal the mode of transmission of the virus at the molecular biology level, analyze the evolutionary source of the new coronavirus, and study the pathological mechanism of the new coronavirus to provide scientific basis for controlling the outbreak.
By detecting the entire genome sequence of the new coronavirus, and then comparing this sequence with the data in the database through an algorithm, it is possible to preliminarily determine its geographic origin.
Align the sequence with the sequence of previous cases. If the sequence is on the same evolutionary tree branch, it can be judged whether these cases are from the same transmission chain or source of infection.
In the face of this epidemic, Hunan Province’s CDC has sequenced 20 samples since the first local case of new coronary pneumonia in 2021 was obtained in Hunan Province on July 28.
Complete viral gene sequencing and traceability within 24 hours
"After the new coronavirus sample is sent to the laboratory, it usually needs to go through multiple steps to complete the test." Zhan Zhifei said that after receiving a positive sample, the staff first conducts a review work, extracts nucleic acid from the sample, and then uses two reagents Perform nucleic acid testing.
The rechecked positive specimens are sequenced using second-generation and third-generation high-throughput sequencing technologies to set up "double insurance" for virus traceability to ensure that there is nothing wrong.
After the virus gene sequence determination is completed, the staff will immediately perform bioinformatics analysis, compare the virus sequence with the sequence in the database, check for mutation sites, and compare homology.
After completing the data comparison, a traceability report must be written in time.
"At present, the Hunan Provincial Center for Disease Control and Prevention has high-throughput second- and third-generation sequencing capabilities for the new coronavirus genome, providing strong technical support for the identification, traceability, prevention and control of the new coronavirus epidemic and other infectious disease pathogens in Hunan Province. "Zhan Zhifei introduced that this technology was only mastered in October last year, and it was previously sent to the National Center for Disease Control and Prevention for testing.
At present, the Hunan Provincial Center for Disease Control and Prevention has trained three technical backbones. All the new coronavirus genome sequencing can be completed within 24 hours, and the complicated situation will not exceed 48 hours.
According to the changes in the epidemic, as long as there are samples, the sequencing process will be started within 24 hours.
Sequencing results are highly homologous to Nanjing
On July 28, since receiving the sequencing of the first local case of new coronary pneumonia in 2021, the Provincial Center for Disease Control and Prevention immediately organized professional and technical personnel to carry out sequencing work day and night, through library preparation, cluster generation, computer sequencing and Data comparison and analysis showed that all the specimens that have completed sequencing results are Delta strains.
The results of the feedback from the National Center for Disease Control and Prevention show that the genome sequence of the new coronavirus is highly homologous to the local case of the Nanjing epidemic reported in Jiangsu Province.
According to the latest epidemic report, Hunan Province has reported a total of 22 confirmed cases of new coronavirus pneumonia from 0:00 on July 20 to 24:00 on August 1, 2021 (3 cases imported from abroad).
The pathogen of this epidemic is a delta mutant strain with a wide range and fierce coming. The general public must not take it lightly. Strictly implement measures such as entering and exiting with codes, measuring body temperature, wearing masks, and keeping distance, effectively reducing the risk of virus transmission and reducing unnecessary People gather.