Blocking novel coronavirus infection: a new way of thinking: How did the virus spread from animal to human?

February 7, 2020 / Biovalley novel coronavirus BIOON/, with the increase in the number of deaths caused by the new coronavirus, people will naturally be worried about how far it spreads in humans Will another such virus appear out of thin air? Animal disease animal animal novel coronavirus will not be the last fatal virus from wild animals to human beings due to continuous deforestation, hunting of wild animals and animal care In fact, there are many viruses in the wild bat and primates that are closely related to SARS and HIV When humans are in contact with wild animals, they will live in these animals It can also spread to humans, sometimes with deadly effects Photo source: hu.wikipedia.org no new virus in the sun? In some cases, animal hosts have reached a state of peaceful coexistence with viruses, just like in the case of bats, while in other cases, these viruses are just as lethal in wild animal hosts and human beings, just like the immune deficiency in chimpanzees and their bodies Like trap viruses, human activity increases the speed at which viruses in wildlife, especially bats, spread to humans Deforestation has made bats closer to human habitats, which has led to the repeated spread and spread of Ebola virus in sub Saharan Africa Of course, the trade of wild animals has also brought SARS to human beings, because bats will transmit the virus in their bodies to civets kept in animal markets About a century ago, chimpanzees were hunted in Cameron Bringing HIV to humans is likely to be an accident in the handling of infected bodies Other recently emerging viruses will also be transmitted to us from bats through domestic animals Hendra virus and Nipah virus were transmitted from fruit bats in 1994 and horses and pigs in 1999 respectively In 2012, mers virus was transmitted to humans from camels, and camels were infected from bats hundreds of years ago When humans raised horses and camels , indirectly infected with Hendra virus and mers In the past, researchers have confirmed that agricultural animals and livestock will bring the most deadly pathogens to human beings For example, hundreds of years ago, smallpox spread from camels, measles spread from cattle The infection of these viruses is not a flash in the pan, but has always been with us Until recently, most children have been infected, and without vaccines, these viruses will remain a critical part of children's health and even death Although novel coronavirus be not at all surprising animal origin, it is not surprising that the virus appears in a market containing many wild animals How far will this novel coronavirus spread? Scientists use statistical R0 strategy to quantify the transmission ability of the virus R0 can measure the average number of people infected by each infected person When more than one person (R0 is greater than 1), the virus can spread indefinitely When the average number of people infected by each infected person is less than 1, the results will be satisfactory Such viruses may spread in the human body for a short time Broadcast, but eventually it will disappear from the crowd At present, the novel coronavirus spreads R0 between 1.4-2.5, which means that it can spread indefinitely As a comparison, the median R0 of seasonal influenza virus is 1.28, which makes it spread worldwide every year R0 is a dynamic parameter with rapid change The transmission rate of virus can be increased by the evolution and adaptation of virus to human beings, and also decreased by the change of human behavior and technology For example, in the recent Ebola epidemic in West Africa, the spread of the virus among people eventually caused more than 28000 people to become infected During this period, the virus evolved to be better at attaching to human cells, while attaching to bat cells became worse With the end of the Ebola epidemic in West Africa, the virus strain adapted to human died out The novel coronavirus may imitate and adapt to humans, thereby increasing its transmission capacity Photo source: the change of human behavior will reduce the transmission of the virus For example, when SARS first appeared, its transmission was rapid and R0 was very high, resulting in 8098 infected persons and 774 dead patients in the world However, SARS does not have the right substance to spread infinitely Soon, scientists clearly realized that the infected people were not infectious until they had severe headache and myalgia and other early symptoms Therefore, the infected people can easily carry out self diagnosis , and be admitted to the hospital before infecting anyone, so its R0 will drop to less than 1, which will ensure that the virus is eradicated Like SARS, Ebola virus has terrible lethality and infectiousness It does not have suitable conditions for its long-lasting existence in human body However, Ebola virus can be transmitted by contacting the body fluids of the infected person, but not by sneezing or coughing in the distance The burial tradition of the West African population has contributed significantly to the early and rapid outbreak of the virus, as family members deal directly with the bodies of the dead When people began to avoid contact with the body fluids of infected people (living or dead), the transmission rate of Ebola virus dropped to R0 < 1; even in the most remote rural areas, without the help of newly developed treatment methods and vaccines, the R0 of Ebola virus would be reduced due to the change of behavior So far, novel coronavirus has not been so lucky for scientists and medical staff to control this virus, because the virus is infectious even before symptoms appear However, novel coronavirus will be less likely to spread if we follow the usual procedures to prevent influenza and influenza infection, such as self isolation, hand washing and avoiding contact with other people's bacteria Besides the change of behavior? Changes in medical technology may help the development of new therapies in the future At present, researchers have developed a portable detection tool, the verecov detection box, which can effectively distinguish SARS, mers and 2019ncov within two hours Long term technical efforts may eventually bring new vaccination and drug treatment methods to patients The risk of novel coronavirus infection and transmission is very high If health officials can reduce the virus to R0 less than 1 by changing their behavior or technical means, we may eliminate SARS globally and even destroy the Ebola virus infection in some areas Novel coronavirus is likely to be with humans if the virus continues to propagate at the present rate or accelerate its transmission through evolution This virus will join the ranks of persistent viruses accumulated from animal hunting or domesticated animals for thousands of years, which may require changes in personal behavior, investment in public health, and new technologies We will continue to innovate and believe that through our joint efforts, we will finally win this epidemic prevention battle Reference materials: [1] Dennis Carroll, Peter daszak, Nathan D Wolfe, et al The global virome project, science 23 Feb 2018: Vol 359, issue 6378, pp 872-874 doi: 10.1126/science.aap7463 [2] complexity of the basic reproduction number (R0) [3] statement on the meeting of the international health regulations (2005) Emergency Committee regarding the outbreak of novel coronavirus (2019-nCoV) 【4】 Summary of probable SARS cases with onset of illness from 1 November 2002 to 31 July 2003 【5】 Origins of major human infectious diseases 【6】 A clue to stopping coronavirus： Knowing how viruses adapt from animals to humans by Frederick Cohan， Kathleen Sagarin and Kelly Mei， The Conversation