Source 丨21 Healthnews21 original work
Author 丨Ji Yuanyuan
Editor 丨Xu Xu
Image source 丨 Figureworm
Recently, the National Health Commission issued the "Catalogue of Pathogenic Microorganisms Transmitted by Humans (Draft for Solicitation of Comments)" (hereinafter referred to as the "New Catalogue"), which incorporates more new understandings of the biological characteristics and pathogenicity of pathogenic microorganisms in the world according to the latest research progress of pathogenic microorganisms and laboratory biosecurity in the world, as well as the discovery of new pathogenic microorganisms in human infection.
Through combing, it can be found that the classification of the new Catalogue will be in line with the classification of WHO, and will be divided into the fourth, third, second and first categories according to the degree of harm of pathogenic microorganisms. Among them, there are 28 species in the fourth category, 71 in the third category, 394 in the second category, and 6 in the first category, for a total of 499 species.
According to public information, the last edition of the "Directory of Pathogenic Microorganisms Transmitted by Humans" was released in 2006, 16 years have passed, including Ebola virus, HIV, etc.; and the new version of the "Catalogue" appeared in the Middle East respiratory syndrome coronavirus, new coronavirus and so on.
It has to be said that the virus existed on earth before humans, and it has always coexisted and coexisted with humans. In the long history of mankind, it is also like a "scythe of death", which has been hanging high above people's heads, and every outbreak of infectious diseases is a harvest of life. Humans have also been fighting the virus, but humans have never been able to completely eliminate it, only let it slowly fade.
With the arrival of the new 2022, the new coronavirus has been ravaging mankind for two years, more than 290 million people have been infected, and more than 5 million deaths have been killed, and the horror and difficulty of the new coronavirus are now known to the world. In fact, in addition to the new coronavirus first discovered in 2019, there are 6 kinds of coronaviruses known to mankind so far: HCoV-229E, HCoVOC43, SARS-CoV, MERS-CoV, HCoV-HKU1, HCoV-NL63.
Are these discolored coronaviruses now completely gone? Will there be a stronger coronavirus in the future than the new coronavirus?
Seven coronaviruses that can infect people
In fact, coronaviruses are a family of hundreds of viruses, most of which infect animals. So far, about 15 different strains of coronavirus have been found worldwide, including those that can infect humans and animals.
The first coronavirus was detected in chickens in the 1930s. It was not until the 1960s that coronaviruses infecting humans were first detected. In 1965, the first human coronavirus was isolated, and the first coronaviruses that could infect humans were HCoV-229E and HCoVOC43.
In November 2002, severe acute respiratory syndrome (SARS-CoV), known as SARS coronavirus (SARS-CoV), was first detected in China and swept through many countries and regions around the world. The incubation period of SARS is usually limited to 2 weeks, usually about 2 to 10 days. People are generally susceptible. SARS patients are the most important source of infection, patients with obvious symptoms are more contagious, and patients with incubation periods or cured are not infectious. The SARS-CoV-induced CASES rate is nearly 10%.
In 2004, HCoV-NL63 was detected for the first time in the Netherlands in infants with bronchiolitis, a lower respiratory tract infection. This virus may have been around for hundreds of years, but we didn't discover it until then. A year later, another coronavirus was discovered in Hong Kong — this time in an elderly patient with pneumonia. It was later named HCoV-HKU1 and was found to exist in populations around the world.
In September 2012, the new coronavirus, the Middle East Respiratory Syndrome Virus (MERS-CoV), appeared again in Saudi Arabia, and MERS later spread to 27 countries and regions in the Middle East, Asia, and Europe. The incubation period is up to 14 days, and the population is generally susceptible. MERS-CoV has a case fatality rate of 35% to 40% caused by MERS-CoV, but it can only be transmitted from camels to humans and cannot be sustained from person to person. No effective cure for the disease has been found.
The latest human-infectable coronavirus is the 2019-nCoV novel coronavirus, which was discovered in late 2019 and is still ravaging humans.
So far, a total of 7 human-infecting coronaviruses have been found worldwide, namely HCoV-229E, HCoV-OC43, SARS-CoV, HCoV-NL63, HCoV-HKU1, MERS-nCoV and 2019-nCoV, of which SARS-CoV, MERS-nCoV and 2019-nCoV are highly infected and have a tendency to strengthen their adaptability. Human coronavirus is not acid-tolerant and alkali-intolerant, the most appropriate PH value for viral replication is 7.2, and it is more sensitive to heat, and as the temperature increases, the resistance of the virus decreases.
From the current situation, the incidence of SARS is the highest, and the case fatality rate of MERS is the highest, but the new crown virus is higher than the incidence of MERS, but the mortality rate is low. SARS-CoV is now gone, and no cases of SARS infection have been reported globally since 2004. MERS-CoV has also largely disappeared. The other 4 coronaviruses persist in populations and communities all year round. These 4 coronaviruses only cause the common cold. However, when they first "jumped" from animals to the human world, they all caused a pandemic.
The eighth type can infect or appear in humans
Humanity's fight against the virus is also a major driving force for the development of human society. With the outbreak of the new crown epidemic, human understanding and exploration of the coronavirus are also deepening.
Dr. Tan Deyong, director of the respiratory production line of Shengxiang Biological Life Science Research Institute, previously introduced that the coronavirus particles are irregularly shaped, with a diameter of about 60-220nm. Coronavirus virions are wrapped in a fatty membrane with three glycoproteins on the surface:
One is that spiked sugar eggs are self (S, Spike Protein, which is the receptor binding site, cytolytic action and major antigenic site);
The second is that small envelopes of sugar eggs are self (E, Envelope Protein, smaller, proteins bound to the envelope);
The third is that the membrane sugar egg is self (M, membrane protein, which is responsible for the transmembrane transport of nutrients, the germination release of the nasous virus and the formation of the virus outer membrane). A few species also include hemagglutinin glycoprotein (He protein, Haemag lutinin-esterase). The total length of the genome is about 27-32 kb, which is the largest genome among known RNA viruses.
Seven coronaviruses, including HCoV-229E, HCoVOC43, SARS-CoV, MERS-CoV, HCoV-HKU1, HCoV-NL63, and 2019-nCoV, produced through multiple mutations, can infect humans. Related studies have shown that similar to SARS-CoV and MERS-CoV viruses, the genome of SARS-CoV-2 (2019-nCoV) is also divided into non-structural genes and structural genes in the western part. The non-structural genes, which account for about two-thirds of the total length of the entire genome of SARS-CoV-2, contain sequences that encode the egg's autoplasm in the western segment, called ORF1a and ORF1b. The region of structural genes that follows encodes structural proteins such as protein § and E protein.
In fact, the first time humans paid the most attention to the coronavirus was in 2003. That year, after researchers detected that the virus that triggered severe acute respiratory syndrome (SARS) in China was a brand new coronavirus, the previous calm was completely broken.
In late 2021, a study titled Novel Canine Coronavirus Isolated from a Hospitalized Patient With Pneumonia in East Malaysia published in the international academic journal Clinical Infectious Diseases showed that a canine coronavirus was discovered by scientists at the University of Florida and Duke University. Named CCoV-HuPn-2018. The virus can directly infect people through animals, but there is currently no evidence that the coronavirus can be transmitted from person to person.
However, Academician Gao Fu, director of the Chinese Center for Disease Control and Prevention, said that this is the eighth coronavirus known to humans after SARS-CoV-2 (2019-nCoV).
How should humans get along with the coronavirus?
In the face of the constant emergence of viruses, is mankind ready to "fight the epidemic"?
As Bill Gates once said publicly in a speech, if there's anything that could kill tens of millions of people in the coming decades, it's most likely a highly contagious virus because we're investing so little in the system to prevent it, and we're not ready to prevent a pandemic.
In fact, in the face of the constant emergence of virus invasion, the information points of all parties also make people realize a fact: for now, the medical community is also in the stage of breaking new understanding of information every day.
Coronaviruses can cause the common cold, severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS) in humans, but there are some aesthetic differences in epidemiological characteristics. Dr. Tedroyon introduced that 10% to 30% of the world's upper respiratory tract infections are caused by four types of coronaviruses, HCoV-oC43, HCOV-NL63 and HCoV-HKU1, accounting for the second largest cause of the common cold, yiji hand and nose virus. Infections are seasonally endemic, with high incidence periods in spring and winter. The incubation period is 2-5 days, and the population is generally susceptible. It is transmitted primarily through human-to-human contact.
"These 4 coronaviruses only cause the common cold. However, when they first 'jumped' from animals to the human world, they all caused a pandemic. The most recent documented world pandemic, possibly caused by coronaviruses, occurred around 1890. After that, we didn't develop a vaccine against these 4 viruses because the symptoms they caused were too mild. Professor Jin Dongyan of the School of Biomedical Sciences of the University of Hong Kong's Li Ka Shing School of Medicine previously pointed out when talking about the mutation of the new crown virus, "At present, the research on the coronavirus is still in progress, and it takes time and patience. Virus mutation is only a small setback in the road to human resistance to the virus, and there may be new mutations in the future, but we can still control it. ”
"Human genomic DNA is made up of about 3 billion PAIRs of DNA bases. In human cells, genomic DNA guides the production of more than 20,000 protein molecules with different functions, maintaining the survival and activity of cells and constructing a complex and exquisite human body. But the surprising fact is that only 2 percent of the DNA in the human genome is used to direct protein production. So what is the remaining 98%? About 8% of it actually comes from viruses. More specifically, there is a class of legacies called "retroviruses." Dr. Tan Saidyong said.
Zhang Wenhong, director of the Department of Infectious Diseases of Huashan Hospital affiliated to Fudan University and head of the Shanghai Medical Treatment Expert Group, once said in a public speech: When a new virus comes to the world, your resistance to it completely depends on the body's immunity. When a new virus reaches the human body, the immunity generated by the human body will not work immediately, because all the cells of the human body have no memory of the new virus, so at this time, the human body needs to fight against it.
Looking back at the history of human struggle with the virus, in addition to doing a good job of protection, human beings also have to praise the kings who provided combat weapons for human struggle - the emergence of various antiviral drugs, like the first dawn of the first opening of the earth, gave mankind finally the opportunity to choke the throat of the virus.
In the wake of the COVID-19 outbreak, the world is struggling to develop vaccines and therapeutics. In 2021, the new crown vaccine took the lead in success and opened mass vaccination around the world, establishing a strong basic immune defense line for the global fight against the "epidemic". According to incomplete statistics from the 21st Century New Health Research Institute, there are currently more than 25 new coronavirus vaccines approved by governments around the world. The cumulative number of COVID-19 vaccine doses worldwide exceeds 9 billion doses.
In addition, in 2021, the new crown treatment drugs are also ushering in a breakthrough in difficulties. According to the 21st Century Business Herald reporter, as of December 2021, a total of 6 new crown neutralizing antibody drugs (including combination therapy) at home and abroad have been approved for use; 2 new crown small molecule oral drugs have been approved for use. In the face of the new crown pneumonia epidemic, whether the "special drug" can stop its progress, build hope for mankind, and become the focus of global attention in the new 2022.
In short, viruses and humans are like shadows, but also embedded in genes. The history of human anti-virus is also a history of human development, which is not only a medical story, but also a battle to change the fate of human survival.