Bats are the host of many zoonotic viruses (Image source / Visual China)
In the early morning of February 7, South China Agricultural University released a message saying that pangolins were found to be potential intermediate hosts for the new crown virus. Previously, researchers have locked the source of the possibility of the new crown virus on bats.
Humanity should be clear that we have never been the masters of the earth. Ironically, as the youngest part of the ancient cycle of earth's ecology, it's becoming easier and easier for us to forget this.
Moreover, the rapid development of human civilization has made us more arrogant and arrogant, and we are more convinced of how different humans are from the wild animals that we regard as "wild meat". As the saying goes, all things are conserved, cause and effect are accompanied, and when they are wantonly preyed and killed by humans, wild animals are also using epidemics as weapons to launch revenge on human beings.
<h1 class= "pgc-h-arrow-right" > night killer: bats</h1>
Bats are animals that are born with more than 100 viruses, and they rarely have the opportunity to directly transmit the virus to humans. However, bowl after bowl of bat soup, a table of "bat" birthday feasts, humans have eaten these viruses that were originally far away from themselves into the body...
< h1 class= "pgc-h-arrow-right" > Ebola haemorrhagic fever</h1>
Ebola virus, full name Ebola haemorrhagic fever, is the number one killer of human health threats in contemporary society.
As a potent infectious disease, Ebola haemorrhagic fever is a zoonotic infectious disease that is extremely lethal to primates, with a biosecurity level of up to 4, and is a virus that even HIV (grade 3) and SARS virus (grade 3) are willing to bow down. Currently, the Ebola virus is recognized worldwide as one of the tools that can be used as a tool for bioterrorism.
▲ Scientific research shows that bats are the host of many zoonotic viruses (image from the Network)
Beginning with a "raid" of 55 villages on the banks of the Ebola River in 1976, the Ebola virus swept through Africa for a time. Of the 24 Ebola outbreaks officially notified by the World Health Organization (WHO) in 2013, there were 2387 confirmed cases and 1590 deaths. Since then, the WHO has sounded the international public health emergency (PHEIC) alarm twice: from 2013 to 2016, the world's largest Ebola outbreak in West Africa caused 28,646 infections and 1,323 deaths; in 2017, the epidemic made a comeback in the Democratic Republic of the Congo (DRC), with 1,100 infected patients and 690 deaths as of April 2019... It can be said that Ebola haemorrhagic fever is the same as the Black Death in medieval Europe where the average fatality rate can reach 50%, and the highest can even climb to 90%, which is the deadliest viral haemorrhagic fever in the world today.
As of now, the scientific community has not fully determined the natural host of Ebola virus, but scholars generally believe that fruit bats are the real culprit of this virus. In 1996, researchers found that among the 24 plant species and 19 vertebrate species, only bats would be infected by Ebola virus without disease, which is one of the important characteristics of identifying the natural host of the virus.
During this period, although genetic fragments of Ebola virus have also been found in the carcasses of gorillas and chimpanzees, given the extremely high lethality rate of the virus to primates, this is inconsistent with the theory of the natural host of the virus, so the possibility of orangutans and other primates being hosts is basically ruled out. In the years since, a growing body of research has pointed to fruit bats as the true host of Ebola virus.
It is worth noting that human consumption and direct contact with infected animals or carcasses can transmit Ebola virus: wild animals such as gorillas can be infected by Ebola virus after eating fruit after being gnawed by fruit bats; locals are infected by the virus after eating "jungle meat" (wild game such as gorillas, antelopes, etc.), and saliva and droplets further lead to human-to-human transmission of the virus.
< h1 class= "pgc-h-arrow-right" > severe acute respiratory syndrome (SARS</h1>).
SARS, also known as Severe Acute Respiratory Syndrome, is a globally serious infectious disease caused by coronaviruses. From its first detection in December 2002 to the basic end of the outbreak in July 2003, SARS patients have confirmed a total of 8,069 cases and died 774 cases worldwide, compared with 7,083 confirmed cases and 647 deaths in China alone.
▲ Civets have been confirmed by scientists to spread the SARS virus from bats to humans (picture from the network)
According to incomplete statistics in 2004, during the worst period of the SARS epidemic, the fatality rate of the disease was considered to be between 7% and 15%, and the mortality rate of people over 65 years old was as high as 55%. Affected by the epidemic, the direct economic loss of China's national economy in that year was as high as 93.3 billion yuan.
At first, it was widely believed that civets were the host of the SARS virus, but a paper published by the Wuhan Institute of Virology of the Chinese Academy of Sciences in 2013 confirmed that the Chinese chrysanthemum bat is the true source of the SARS virus, and the civet beaver, as an intermediate host, indirectly transmitted the virus to humans after being infected with the virus by the Chinese chrysanthemum bat.
< h1 class = "pgc-h-arrow-right" > Middle East respiratory syndrome (MERS</h1>).
MERS, full name Middle East respiratory syndrome, is another bat killing of humans through the hands of other wild animals, only this time the intermediate host changed from civets to camels.
In 2012, the first patient infected with the MERS virus was confirmed in Saudi Arabia. In the early days, because the clinical symptoms of patients were quite similar to those of SARS virus, MERS virus was named "SARS-like virus", which is the sixth coronavirus known to mankind.
▲ Middle East respiratory syndrome is a bat through the hands of other wild animals to kill humans, only this time the intermediate host changed from a civet to a camel (picture from the Network)
From first detection in September 2012 to April 2014, 92 people worldwide lost their lives from MERS virus infection, during which time the MERS fatality rate was as high as 53%. In May 2015, South Korea's first confirmed case of MERS was discovered, and the MERS virus caused a massive panic. As of the basic end of the epidemic in July 2015, more than 16,000 people in South Korea have been quarantined for MERS, with 186 confirmed cases and 36 deaths. In the following years, the MERS virus has emerged from time to time, and as of November 2019, there have been 2494 confirmed MERS patients worldwide, with 858 deaths, with an average fatality rate of 34.3%.
The Saudi Arabia region is the epicenter of MERS outbreaks. Originally, camels were thought to be the real culprits of the MERS virus, but scientists eventually confirmed that the Egyptian tomb bat was the true host of the MERS virus, because humans came into contact with or ate camels infected with the virus and were indirectly invaded by the MERS virus.
An Ebola virus particle has a significant "shepherd's cane" structure. This is one of the earliest photographs of the Ebola virus, taken on October 13, 1976, by Frederick M. Thompson, who was working at the Centers for Disease Control at the time. A. Murphy. Mysterious structural proteins are entangled like ropes around single strands of RNA containing a genetic code. Magnification: 112000
<h1 class= "pgc-h-arrow-right" > thousand-year-old demon rat</h1>
Rodents have never been weaker than bats in the transmission of diseases. Who can achieve "slaughtering the city in one day" in the era of cold weapons? The answer is rats.
On the one hand, the rapid expansion of human towns not only encroached on the original homeland of rats, but also forced the tenacious rats to adapt to people, providing a hotbed for them to transmit diseases to humans; on the other hand, humans have no shortage of hunters since ancient times, and the so-called "gourmets" who have brought various wild rats to the table have invisibly pushed humans closer to disaster.
<h1 class= "pgc-h-arrow-right" > the Black Death</h1>
As one of the worst plagues in humans, the Black Death is a fierce natural epidemic caused by Yersinia pestis infection, and wild rodents such as marmots and marmots are its main hosts. In the Middle Ages, because the disease was extremely contagious, the fatality rate was extremely high, and the symptoms of subcutaneous bleeding and blackening of the patient after infection, it was called the "Black Death".
In the hundred years that have ravaged human society, the Black Death has wiped out nearly 75 million people worldwide, and even indirectly affected the development process of European capitalism and even human society.
▲ The apocalyptic scene of the Black Death "Slaughter City" in the painter's pen (picture from the Internet)
In fact, long before the Black Death in Europe, the Byzantine Empire had a massive outbreak of plague (Justinian plague) in 541-542 AD that killed nearly 40% of the inhabitants of Constantinople and 25% of the total population of the Eastern Roman Empire. Because the plague came and went quickly and did not recur, it was quickly submerged in the long river of history. It was not until October 1347 that the first case of the Black Death was discovered in Sicily and quickly swept through Italy in less than four months. In two years, Hungary, Poland, Prussia, Scotland, Russia... More and more European countries were affected, corpses piled up, and half of Europe's population lost their lives to the Black Death in four years.
Since then, there have been many large-scale outbreaks of the Black Death in Europe, Italy in 1629-1631, London in 1665-1666, Vienna in 1679, Marseille in 1720-1722, Moscow in 1771... It can be said that before the discovery of antibiotics, the quarantine of the town until the last epidemic patient died on its own, this "resigned to fate" epidemic prevention method is almost the only way for humans to fight the Black Death.
Needless to say, rats were the culprit of the Black Death: in the Middle Ages, due to the influence of climate and human activities (such as the military activities of the Mongol Empire), rats were forced to "flee" from arid steppes to densely populated European towns, along with rats, of course, pestis bacillus. With the help of the "mouth" of the fleas parasitic rats, they spread in each seemingly careless bite of the latter, easily breaking through the already vulnerable sanitary defense line of human society at that time and killing humans.
<h1 class="pgc-h-arrow-right" > monkey ceiling</h1>
In 2018, British scientists issued a warning to warn humans of a "mutant ceiling"
The comeback of the monkey smallpox.
Monkey smallpox, also known as monkey pox, is a close relative of the smallpox virus that once ravaged the world, and is a zoonotic infectious disease, of which primates are the most susceptible to infection. Unlike smallpox virus, the highest fatality rate of monkey smallpox virus is only 11%, but children are mostly susceptible people, and the skin of the affected area will become "numb" after recovery.
In 1970, 10 years before humans officially declared the eradication of the smallpox virus, the monkey ceiling virus first appeared in the Democratic Republic of the Congo. Since then, the disease has had a second local outbreak in 1996-1997.
In 2003, a monkey smallpox outbreak suddenly broke out in 6 states in the United States, including Ohio and Missouri, and a total of 71 people were confirmed to be infected within a month, but fortunately no one died. After investigation, it was found that the culprit of the epidemic in the United States was a new pet in the patient's home, a Gambian rat (prairie marmot).
▲In 2003, the first case of monkey smallpox virus appeared, and the picture showed the patient's hand (picture from the Network)
At present, humans can not accurately identify the true natural host of monkey smallpox virus, but since 2003, scientists have repeatedly found this virus in rodent wild animals such as squirrels and Gambian rats, and the Gambian rat is the most suspected, scratched, bitten, and direct contact with infected pets (such as cats and dogs) will cause human infection, air and contact transmission can accelerate the human-to-human transmission of the virus.
<h1 class="pgc-h-arrow-right" > typhus</h1>
As an acute infectious disease, typhus is another disease brought to humans by rodents. In general, typhus can be divided into epidemic typhus and endemic typhus, the latter of which is currently recognized as a naturally occurring disease.
Endemic typhus is caused by Rickettsia Mooseri, and because its main host is rodents, which are then transmitted to humans by rat lice, they are called flea typhus or murine typhus.
▲ Typhus case, the picture is the patient's hand (picture from the network)
As a global epidemic, typhus is still infected with 1 million cases per year, especially in the underdeveloped regions of asia and the Pacific. Although the fatality rate is not as high as that of the Black Death, if timely treatment is not taken, the fatality rate of typhus can reach 70%, and infected patients will have symptoms such as persistent high fever, arrhythmias, and manic trance.
As early as World War II, typhus ravaged Myanmar and Ceylon. In his memoirs, The American military scientist MacArthur pointed out that in the Battle of Kokoda Trail in World War II, the ratio of the number of people killed by typhus to the number of deaths from weapon wounds was as high as 5:1. At the same time, the Allies suffered from typhus in the Battles of New Guinea and Guadalcanal.
< h1 class= "pgc-h-arrow-right" > Lassa fever</h1>
Unlike the Black Death and typhus, Lassa fever caused by Lassa virus does not need to be transmitted by parasites in rats, but directly contaminates human food and daily necessities through rodent feces and urine, and then directly transmits the virus to humans. Currently, the virus reservoir of the disease is thought to be a species of rodent called Mastomys.
▲ The virus host of Lassa fever is believed to be a rodent called Mastomys (image from the internet)
As a highly contagious international infectious disease, at present, Lassa fever is mainly concentrated in Ghana, Guinea, Liberia, Sierra Leone and other West African countries, of which Sierra Leone and Liberia are the most serious.
According to incomplete statistics, the number of infections of the disease in West Africa is about 100,000-300,000 cases per year. The incubation period of Lassa fever is very long (6 days to 1 month), and the early symptoms are very difficult to identify, although the fatality rate is not high (1%), but the death rate is mostly concentrated in children, and the mortality rate of critical cases can reach 15%, of which the fatality rate for pregnant women is as high as 80%. Notably, there was an outbreak of Lassa fever in Nigeria in 2018 that resulted in more than 300 people being confirmed to be infected in one month, with a mortality rate of more than 20% at one point.
<h1 class = "pgc-h-arrow-right" > "close relatives" cannibalism: primates</h1>
As "close relatives" of humans, primates such as chimpanzees and monkeys have also sent a chronic killer to humans: human immunodeficiency virus (HIV), that is, HIV. For a long time, humans blindly believed that the blood of gorillas could strengthen the body and aphrodisiac, and this desire provoked them to raise their butcher knives and hunt gorillas more brazenly. Ironically, however, primates, who are considered "inferior" by humans, chose to use a special chronic virus to start a century-long revenge.
▲White-naped white-browed monkey is considered a natural host for HIV- (Image from the Internet)
Unlike the infectious diseases mentioned above, HIV is a lentivirus that infects the cells of the human immune system, a type of retrovirus, which is not transmitted through droplets and normal contact, and HIV-infected people are called AIDS only after the onset of the disease.
HIV appeared in Africa in 1920, and in 1981 humans were first diagnosed with the virus in U.S. medical facilities. Because the Reagan administration at that time did not pay attention to the dangers of AIDS, more and more patients were infected due to blood transmission. Ironically, at the beginning of the discovery, European and American scholars had been "big hits" because of the naming of the virus and the technical patents, until 1986, when it was finally uniformly named "HIV", in order to better reflect the nature of the virus that causes immunodeficiency rather than carcinogenesis.
According to the WHO, as of 2018, 37.9 million people worldwide have been confirmed to be infected, and 8.1 million people do not even know they are infected with HIV. In 2018 alone, 770 000 people died of AIDS, with another 1.7 million new infections. Most frighteningly, this number is still growing, especially in the Sahara and sub-Africa, followed by South Asia, Southeast Asia, and in recent years, the increase in AIDS in East Asia, Eastern Europe and Central Asia has shown a rapid growth trend.
HIV viruses can be divided into HIV-1 and HIV-2. It is now widely believed that AIDS is primarily caused by HIV-1, and that its natural host is a chimpanzee from southern Cameroon, which is the first time that humans have fully identified all sources of HIV strains.
In 2018, scientists confirmed that the natural host of HIV-2 is a white-naped white-browed monkey that lives in West Africa. (Written by/Reporter Wang Xueying, Photo editor Ji Jingjing)
TIPS:
These wild animals are "carrying poison"!
The source of these deadly viruses that frighten human beings basically comes from wild animals.
Even if technology is so advanced today, the primates of all things at the top of the food chain, human beings can't beat all of them, these deadly viruses may teach us one thing - reverence for nature.
(Photo/Reporter Wang Xueying)
Review expert: Dr. Ximena Aguilera, Director of the Center for Epidemiology and Health Policy at the University of Desaro in Chile
This article is jointly compiled by China Digital Science and Technology Museum and Beijing Science and Technology News
Producer: Popular Science Central Kitchen
Producer: Beijing Science and Technology News | Science plus client
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