COVID-19

Bats are innocent, let's find the real culprits of the coronavirus

Bats are innocent, let's find the real culprits of the coronavirus

For the biologist Rodrigo Medellín Legorreta, a researcher at the Institute of Ecology (IE) of the National Autonomous University of Mexico UNAM, bats are the most unfairly abused animals in the world, they are one of the species that have a negative image, such as scorpions, snakes and sharks. "None of these groups does more for your well-being today like bats, they touch every day of your existence with their benefits."

Medellín Legorreta, responsible for the Laboratory of Ecology and Conservation of Terrestrial Vertebrates of the IE of UNAM, explained that bats are the most important controllers of agricultural pests of coffee, tea and cotton; the ceiba, tequila and mezcal agaves are pollinated by bats. Many Mexican fruits depend on this species to disperse their seeds, "it is only fair that we give them the respect, affection and care they deserve for everything they do for us."

Regarding the latest news that states that bats could be the origin of the Wuhan coronavirus, China, Rodrigo Medellín said that there are unscrupulous researchers who blame this species of pests and diseases. "They are completely out of date, those of us who know them have to defend them, do not be fooled by pseudo investigations."

He explained that it is human beings who are affecting all the ecosystems in the world, “we are getting into places where we did not reach before, where there are pathogens that did not affect us before, it may be that someone touched a plant or caressed an animal or He ate it and could have been infected with this virus ”.

In this sense, he pointed out as alarmist and false that type of news that only causes damage to the species. "They are one of the animals that offer the most environmental services, it is estimated that bats every night consume 10 tons of insects."

In such a way that if the bats were to disappear, in three or four months a large part of the crops would be destroyed by insect pests. Likewise, fruits such as guava and plum, among others, would be lost, since the bat is the pollinator of these fruits or plants.

And if that were to happen, Mexico would be one of the most affected countries, since it is the sixth country with the highest diversity of bat species, below Brazil, Ecuador, Peru, Colombia and Venezuela.

"These are the practices carried out in China and its process of using wildlife, they are being exposed to various pathogens to which humans were not exposed before. We are part of an ecosystem and we have invaded many, the species that were there have more right to live there, let us protect the different species and their habitat ”, concluded the specialist.

Bats: a key piece for ecosystems

Bats are mammalian vertebrates covered with very short hair that helps them protect themselves from humidity and cold. There are about 1,000 species in the world, being one of the most diverse groups of mammals. These animals have nocturnal habits: they leave their shelters at dusk and roam the forest in search of food or a mate, returning to the shelter before dawn where they will remain resting all day.

Of all the species of bats in the world, there are only three that feed on blood, and of these only one feeds on mammalian blood, which is the common vampire. 70% of them feed on insects, such as moths, flies, mosquitoes and beetles (they can eat half their weight in a single night) and the rest feed on pollen and fruits, or they are carnivores and can eat frogs, lizards, mice and sometimes other specimens of their species.

The lack of information makes human attacks the greatest threat faced by bats, due to their particular appearance and nocturnal habits. The myth that they are "blood-sucking animals" is what affects these mammals the most, especially among the livestock population. For one of the species, the vampire bat, attacks cattle, biting them. But it is not the bite itself that harms livestock, rather the bites can cause a number of infections and diseases in livestock. In cows, milk production decreases and even the death of the animal, which causes economic losses for farmers.

Despite this, bats are animals that regenerate and maintain the environments where other species live.

Why are bats important?

The presence of bats in ecosystems has many benefits, among them are:

• Control of insect pests without causing damage to the environment, as if exterminators do.

• They disperse seeds and pollinate flowers of ecologically important plants. (Some 500 species of flowers around the world depend on bats to pollinate)

• Your saliva contains an anticoagulant

• They eliminate mosquitoes, which are often carriers of dengue, chikungunya and other diseases.

Coronavirus: How serious will the crisis be?

As the coronavirus outbreak spreads in China, a flood of early research offers a clearer picture of how the pathogen behaves and the key factors that will determine whether it can be contained.

Although the virus is a serious public health concern, the risk to most people outside of China remains very low - in fact, seasonal flu is a more immediate threat. To avoid any viral illness, experts advise that we wash our hands frequently and do not go to school or the office when we are sick. Most healthy people do not need masks, and stockpiling them may contribute to shortages for health care workers who do need them, experts said.

How contagious is the virus?

The scale of an outbreak depends on the speed and ease with which a virus is transmitted from person to person. Although investigations have only just begun, scientists have estimated that each person with the new coronavirus could infect 1.5 to 3.5 people if effective containment measures are not taken.

That would make the virus about as contagious as SARS, another coronavirus that circulated in China in 2003 and was contained after it sickened 8,098 people and killed 774. Respiratory viruses like this can be transmitted through the air, enveloped in tiny droplets that are produced when a sick person breathes, speaks, coughs, or sneezes.

Those drops fall to the ground several centimeters away. That makes the virus more difficult to catch than other pathogens like measles, chickenpox and tuberculosis, which can travel tens of meters through the air. However, it is easier to contract than HIV or hepatitis, which are only transmitted through direct contact with the bodily fluids of an infected person.

If each person infected with the new coronavirus infects two or three more, that may be enough to sustain and accelerate an outbreak if nothing is done to reduce it.

Coronaviruses like the Wuhan virus can travel only about two meters from the infected person. How long they can survive on surfaces is unknown. Other viruses, like measles, can travel up to 100 feet and survive for hours on surfaces.

Compare that to a less contagious virus, like the seasonal flu. People with the flu usually infect, on average, 1.3 people.

However, the transmission figures for any disease are not fixed. They can be reduced by effective public health measures, such as isolating sick people and following up on individuals with whom they have had contact. When world health authorities methodically followed up and isolated people infected with SARS in 2003, they were able to reduce the average number of infected individuals per sick person to 0.4; enough to stop the outbreak.

Health authorities around the world are making a great effort to try to replicate that strategy.

So far, the number of cases outside of China has been small. However, in recent days, cases have emerged in several countries, including the United States, with people who have not visited China. And the number of cases within China has accelerated, far exceeding the rate of new SARS cases in 2003.

How long does it take to have symptoms?

The time it takes for symptoms to appear after a person is infected can be vital for prevention and control. That time, known as the incubation period, can allow health officials to quarantine or observe people who have been exposed to the virus. However, if the incubation period is too long or too short, these measures can be difficult to implement.

Some illnesses, like influenza, have a short incubation period of two or three days. However, SARS had an incubation period of almost five days. Also, it took four to five days after symptoms started for people to transmit the virus. That gave officials time to stop the virus and contain the outbreak effectively, said Allison McGeer, an infectious disease specialist at Mount Sinai Hospital in Toronto, who was at the forefront in Canada of the SARS response.

Officials at the Centers for Disease Control and Prevention estimate that the new coronavirus has an incubation period of two to fourteen days. However, it is not yet clear whether a person can transmit the virus before symptoms develop or whether the severity of the disease affects how easily a patient can spread the virus.

How long will it take to develop a vaccine?

A coronavirus vaccine could prevent infections and stop the spread of the disease. However, vaccines take time.

After the SARS outbreak in 2003, it took researchers about twenty months to have a vaccine ready for human testing. (The vaccine was never needed because they ended up containing the disease.) With the Zika outbreak in 2015, researchers were able to reduce the development period of the vaccine to six months.

Now they hope that the work of the previous outbreaks will help reduce that period even more. Researchers have already studied the genome of the new coronavirus and found the proteins that are crucial for infection. Scientists from the National Institutes of Health, Australia and at least three companies are working on possible vaccines.

Experts step up development of coronavirus vaccine

Scientists have succeeded in taking the crucial first step towards developing an effective vaccine against the new coronavirus (nCoV): Doctors from the Chinese Center for Disease Control and Prevention (CDC) have isolated the new virus and analyzed its genetic information Xu Wenbo, director of the Institute for Viral Diseases, told Xinhua news agency.

Never before in human history has the leap of a new pathogen from an animal - yet unknown - to man been discovered so quickly, a virus was completely decoded, reproduced in cell culture and existing knowledge was made available so quickly in the form of scientific publications around the world.

Development of a vaccine

Just as Chinese researchers, who have already started developing vaccines, doctors in the United States, Australia and other countries are working on a solution: in the United States, a new vaccine research group from the National Institute of Health (NIH) led by Anthony Fauci, director of the Institute of Allergies and Infectious Diseases (NIAID), met to coordinate the strategy for the development of the vaccine.

In a recent article in the Journal of the American Medical Association, Fauci writes that vaccines that have already been developed against two other dangerous coronaviruses such as SARS and MERS may also provide a good basis for developing a vaccine against nCoV.

In the so-called "platform approach," researchers use a harmless cold virus and incorporate components of the coronavirus to activate an immune response.

In 2003, the research group led by Andrea Gambotto, a molecular physician at the University of Pittsburgh, generated three different types of vaccine. These were based on several proteins: the spike protein S1, which is responsible for the formation of the crown-shaped tips (“spikes”) in coronaviruses, a membrane protein and a nucleocapsid protein from the original SARS virus. Rapid development was only possible because the entire SARS virus genome could be decoded in record time.

Unknown risks: the mutability of the virus

However, one factor that hinders the development of vaccines against coronaviruses lies in the fact that they are extremely versatile. The same thing happened with SARS. Doctors feared that vaccination with the active substance spike protein might even accelerate the penetration of certain virus variants. Fauci considers, however, that both the spike vaccine and the nucleocapsid protein vaccine are a possible basis for future research.

Australian scientists led by Keith Chappell from the University of Queensland joined forces with other doctors to develop a new vaccine with the help of the so-called molecular clamp. The idea of ​​this vaccine is to make the previous stages of the viruses look like fully grown and stable viruses. This allows the immune system to attack them even before they fuse with the cell.

This is also a "platform approach," Chappel told Reuters. The method has already been shown to work against other dangerous viruses such as Ebola, MERS or SARS, but only in the laboratory.

The biggest challenge, as with SARS, is again the speed of vaccine development. Fauci's American researchers hope to be ready in three months to test a vaccine in humans.

Anti-virus drugs

Whether or not the epidemic goes that far also depends on whether a completely different approach might be helpful: treatment with antiviral drugs. Fauci says that several broad-spectrum antiviral drugs could be considered, such as the RNA polymerase inhibitor Remdesivir, known for treating Ebola, or the combination of the active substances Lopinavir and Ritonavir that have been tested in the treatment of HIV.

Another very different approach is to fight the virus with so-called monoclonal antibodies, that is, immunologically active proteins, which trigger a very specific immune response in the body.

Herbert Virgin of Vir-Biotechnologies in Illinois, United States, said his company has already developed antibodies that have been shown to be effective against SARS and MERS in laboratory tests. Some of them were able to neutralize the coronaviruses. "Perhaps they also have the potential to treat the Wuhan virus," Virgin said.

Quarantine remains the most effective measure

Whether any vaccine is released on the market also depends on the subsequent course of the epidemic. Chinese authorities currently use the most effective means to contain the disease: isolate patients and quarantine entire cities. 43 million people are affected by the measure.

An nCoV infection appears to be much less fatal than one with SARS. In that case, approximately 10 percent of the 8,000 people proven to be infected died. Now, instead, the number of infected people is increasing rapidly and steadily, but only relatively few patients die from the infection. And they are mostly older people with previous illnesses.

Professor Mark Harris, a virologist at the School of Molecular and Cellular Biology at the University of Leeds, estimates that the death rate is only 0.1 percent. In his estimate, he takes into account the probable high number of unreported cases of patients with a relatively mild course of the disease who do not even go to clinics and are therefore not recorded in official statistics. If your theory is correct, the new virus would be slightly more dangerous than the usual seasonal flu.

There is still a lack of clarity on how highly contagious the virus really is. Chinese health authorities had temporarily assumed that carriers of the nCoV virus could infect other people if they did not show symptoms themselves. While that would explain why the epidemic could spread so quickly, doctors have now questioned this assessment.

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