Why wild animals are susceptible to viral transmission

Editor’s note: Zhong Nanshan academician recently said that bamboo rats, crickets and other wild animals may be the new coronavirus to human transmission of the “main culprit.” Which wild animals are easy to become the “hosts” of the virus, and why are they less susceptible to new viruses? How should people prevent it? In response to the above-mentioned problems, the Global Times reporter interviewed a number of domestic experts in related fields on the 22nd.

Why wild animals are susceptible to viral transmission

Journalist of this newspaper, Hao Fan Lingzhi, special correspondent of this newspaper, Ren Zheng

Which animals are susceptible to virus “host”

On the evening of January 20, Zhong Nanshan, head of the high-level expert group of the National Health and Reform Commission and a member of the Chinese Academy of Engineering, in an interview with CCTV, transmitted the virus to the crowd stoking the source of wild animals sold at the South China Seafood Market in Wuhan. He analyzed that through preliminary epidemiological analysis, through the wild animals to infect people more likely, such as bamboo rats, crickets.

Gao Fu, a member of the Chinese Academy of Sciences and director of the Chinese Center for Disease Control and Prevention, also said at a press conference at the State News Agency that the source of the new coronavirus is illegally sold wild animals at a seafood market in Wuhan.

Which wild animals are prone to human disease? Singapore’s “Joint Morning Post” website reported on the 22nd, china’s top expert Zhong Nanshan as the possible source of the new coronavirus bamboo rat, in recent years in mainland China has been large-scale artificial breeding, but also in the network of celebrities to promote the Chinese table food. The article also quoted Hong Kong media reports that the bamboo mouse in a strong shape, mainly living in subtropical forests, thickets and bamboo forests, mainly to bamboo for food, because of the large body size of meat, rich nutritional value, has a higher economic and medicinal value.

As during the SARS outbreak, bats are highly suspected of being responsible for the spread of the new coronavirus. On January 22nd, Tongji Hospital, affiliated with Huazhong University of Science and Technology, published an article entitled “A Quick Guide to the Diagnosis and Treatment of New Coronary Virus pneumonia”, saying that after a virus sequence comparison analysis, Tongji Hospital Expert Group speculated that the natural host of the new coronavirus disease may be bats. According to Ning Qin, director of the hospital’s infection department, there is likely to be an unknown intermediate host vector in the course of transmission from bat to human.

Yang Zhanqiu, director of the Institute of Medical Viruses at Wuhan University, believes that the real culprit stakes further research to be determined. 22 he told the Global Times reporter, strictly speaking, should be found in the animal’s body live virus, to prove that it is the original host, if only from the animal gene fragments found on the basis is only ambiguous. Yang Zhanqiu believes that the new coronavirus not only originated in bats, but may also be parasitic in different animals. With so many hosts, it’s too early to lock in bats.

The BBC said on the 22nd, that year’s SARS incident, medical experts initially determined that the beaver is the cause of the virus. Years after SARS, Chinese researchers published a paper in the journal Nature, saying that the real culprit of the SARS virus is the Chinese chrysanthemum manta ray.

In recent decades, the world’s major infectious diseases have always been closely related to animals. More than 60 percent of emerging human infectious diseases come from animals, and more than 70 percent of these zoonotic animal-borne diseases come from wild animals, according to a study published in the journal Public Library of Science, Neglected Tropical Diseases, according to the Associated Press. Research shows that about 85 percent of respondents ate primate meat at some point in their lives.

More than 10 percent of rodents are host edgy animals, carrying 85 different diseases, researchers at the Cary Ecosystem Institute and the University of Georgia wrote in the journal Parasitic Trends. Although the study covered few primates, 21% were hosts. The researchers also noted that although bats are “notorious,” they carry fewer diseases (25 species) than rodents (85), primates (61) and carnivores (83). In addition, Europe and Russia are global hotspots for rodent hosts, Central and South America are bat hotspots, and primate hosts are concentrated in equatorial Africa. Moreover, mammals carry more bacteria than other pathogen types.

What should I do besides not eating?

With the development of the epidemic, the Chinese Internet has been constantly circulating pictures of people eating bats and other wild animals. So how do we prevent new viruses from spreading from animals to humans?

Yang Zhanqiu told the Global Times that eating wild animals cooked at high temperatures does not themselves cause disease, because after the high temperature, the virus parasitic environment has been destroyed. But people are at great risk of being exposed to these virus-carrying wildlife in the process of acquiring and processing. Yang Zhanqiu believes that to eliminate the risk of this infection, or the need for the masses not to blindly eat wild animals, to cut off the risk of virus transmission to the greatest extent.

The anonymous immunologist mentioned above told the Global Times that, in addition to not eating the wild animals, try not to keep wild animals caught from the wild and not to make contact. Also pay attention to wild animals that may carry parasites, fleas, mosquitoes and can also transmit the virus from wild animals to humans, such as plague. In addition, wildlife secretions or feces, as well as its contaminated items should also be as little contact, not to contact.

The Website of the Chinese Society of Experimental Zoology says the pathogen is prone to human infection and spread, which is linked to the current way of life. Now humans live more intensively and interact more frequently. Natural destruction, frequent animal trade, and a warming climate all contribute to the spread of pathogens. Once pathogens are transmitted from person to person, activities such as convenient and frequent travel are easier to spread pathogens quickly around the world through infected people, becoming a global public safety issue.

The Voice of Germany said Tuesday that WHO recommends washing hands with soap and water after contact with animals and animal products to avoid touching the eyes, nose and mouth. Avoid contact with sick animals and spoiled meat. Avoid contact with stray animals and waste water in the market. However, even in areas with high outbreaks, meat can be eaten safely if thoroughly cooked and properly treated during food preparation.

WHO also recommends that if you work in a fresh market, wash your hands with soap and water when you come into contact with animals and animal products. Disinfect equipment and work areas once a day. Wear protective clothing, gloves and face protection when handling animals and fresh animal products. Take off your protective clothing after work, clean it daily and leave it in the work area to avoid contact with unwashed work clothes and shoes.

Why the new virus “prefers” wild animals

Why do new viruses always live in wild animals, especially mammals, and why do they not pose serious harm to these animals themselves?

Yang Zhanqiu explained that an important characteristic of the virus is that it has to live in life to survive, and the natural world has a wide variety of organisms, widely distributed, so a variety of organisms become a reservoir of viruses. Some animals have weak pathogenicity of the virus, while some animals have a virus in the long transmission chain through multiple mutations, thus becoming very aggressive, causing widespread concern.

An immunologist, who did not want to be named, told the Global Times in an interview that wild animals grow in nature, it is difficult to fully manage them, wildlife epidemic prevention work is almost difficult to carry out, so wild animals will have a lot of potential pathogen infection. And because of survival in the wild, it is also difficult for humans to detect pathogens infected with animals.

“When these viruses live in other organisms, they do not appear to be disease, because the virus needs to rely on long-term parasites in animals to complete their own life activities, so generally does not cause the host to become sick, the host also has a corresponding resistance to the virus,” Yang said. “But when the virus starts to spread outwards and between different intermediate hosts, it tends to mutate, creating the effect of making the host disease-causing.”

After animals are domesticated by humans, are they much less harmful to the virus? Yang Zhanqiu affirmed this. He told the Global Times that there are viruses in wild animals and reared animals, and the difference is in the amount. Because the environment of animal spending is relatively clean, or artificial disinfection treatment, is not conducive to the growth of the virus. Sometimes, the same virus does not exhibit the same characteristics in poultry and livestock as it does in wild animals. Because viruses are to survive, they must adapt to different host environments.

The immunologists believe that if there is no effective quarantine of the wild animals kept, then these animals may still have pathogens in them, and may continue to spread under artificial breeding, and even mutate, resulting in more infectious to the human body.