Preliminary progress has been made in pathogen identification of unexplained viral pneumonia in Wuhan.

　　Xinhua News Agency, Beijing, January 9 (Reporter Qu Ting) Recently, the reporter interviewed Xu Jianguo, the leader of the expert group for preliminary evaluation of pathogen test results and an academician of China Academy of Engineering, on the progress of pathogen identification of unexplained viral pneumonia in Wuhan. He said that the expert group believed that the pathogen of this unexplained viral pneumonia case was preliminarily determined to be novel coronavirus.

　　Question 1: At present, what progress has been made in the etiological identification of viral pneumonia with unknown causes in Wuhan?

　　Xu Jianguo: As of 21: 00 on January 7, 2020, a novel coronavirus was detected in the laboratory, and the whole genome sequence of the virus was obtained. By nucleic acid detection, 15 cases were found to be novel coronavirus positive, and the virus was isolated from a positive patient sample, showing a typical coronavirus morphology under the electron microscope.

　　The expert group believes that the pathogen of this unexplained viral pneumonia case was initially determined to be novel coronavirus.

　　Question 2: How was this pathogen identification organized?

　　Xu Jianguo: Tissue laboratory used genome sequencing, nucleic acid detection, virus isolation and other methods to detect the pathogens of patients’ alveolar lavage fluid, throat swab, blood and other samples.

　　Question 3: What procedures are needed to confirm the pathogen?

　　Xu Jianguo: To confirm the pathogen causing an epidemic disease, the following points should be met: (1) Suspected pathogens must be found in all patients, and pathogenic nucleic acids can be detected in patients’ clinical samples; (2) The pathogen can be successfully isolated from the clinical samples of patients; (3) Isolated pathogens can cause the same disease symptoms after infecting host animals. However, the antibody titer of the pathogen in the serum of patients in recovery period increased by 4 times, which can help to determine the pathogen.

　　The discovery of nucleic acid, genome and antibody evidence of pathogens from patients can be completed in a short time. Scientific research such as isolation and pathogenicity identification of pathogens will take several weeks. The development of specific drugs and vaccines for a new pathogen may take years to complete.

　　Question 4: What should be done next?

　　Xu Jianguo: The expert group believes that the pathogen of this unexplained viral pneumonia case is preliminarily determined as novel coronavirus, and the next step needs to be combined with etiological research, epidemiological investigation and clinical manifestations for expert judgment.

　　Question 5: What is coronavirus?

　　Xu Jianguo: Coronavirus is a kind of pathogen that mainly causes respiratory and intestinal diseases. There are many regularly arranged protrusions on the surface of this kind of virus particles, and the whole virus particle is like a crown of an emperor, hence the name "coronavirus". Besides humans, coronavirus can also infect many mammals such as pigs, cows, cats, dogs, minks, camels, bats, mice, hedgehogs and many birds. So far, there are six known human coronaviruses. Among them, four coronaviruses are common in the population, with low pathogenicity, and generally only cause mild respiratory symptoms similar to the common cold. Two other coronaviruses — — Severe acute respiratory syndrome coronavirus and Middle East respiratory syndrome coronavirus, also known as SARS coronavirus and MERS coronavirus, can cause serious respiratory diseases. Novel coronavirus, which caused the epidemic, is different from the human coronavirus that has been found. Further scientific research is needed to understand the virus.