Scientists focus on bats for clues to prevent the next epidemic

RIO DE JANEIRO (AP) – Night fell in Pedra Branca State Park in Rio de Janeiro as four Brazilian scientists turned on their flashlights to walk on a narrow trail of mud in the Ga flash rainforest. The researchers were on a mission: to catch bats and help prevent the next global epidemic.

A few meters ahead, almost invisible in the dark, a bat made high-striped squeaks as its wings pulled it against a thin nylon mesh. One researcher named the bat, which used its pointed teeth to bite its gloved fingers.

The November night outing was part of a project to collect and study the virus present in wild animals at the Fiocruz Institute, run by the Brazilian government – including Ton, which many scientists believe was linked to the outbreak of COVD-19.

The goal now is to identify other viruses that can be highly contagious and deadly in humans, and to use that information to devise plans to prevent them from ever infecting them – before the next possible global disease epidemic begins. To control.

In a highly connected world, like a coronavirus, an outbreak in one place endangers the entire world. The Brazilian team is one of only one in a global race to reduce the risk of another epidemic this century.

Some feel that, considering the next global outbreak too soon, the world will still face the disastrous consequences of the current situation. But scientists say it’s like this, without sensible intervention, that another novel virus would jump from an animal to a human host and find a way to spread like wildfire.

As the epidemic has shown, modern transport can spread the disease to every corner of the world in a matter of hours and spread easily to densely populated cities.

Infectious Diseases Specialist Dr. of Christian Medical College at Vellore, South India. According to Gagandeep Kang, there is no question of when he is.

He drew attention to previous research Due to population density and increasing human and livestock invasion in its ganse tropical forests associated with wildlife, India was one of the most probable destinations for such a “spillover” event.

It is no coincidence that many scientists are focusing on the world’s only flying mammal – the bat.

Bats are thought to be the original or intermediate host for multiple viruses that have produced recent epidemics, including COVD-19, SARS, MERS, Ebola, Nipah virus, Hendra virus, and Marburg virus. 2019 study The five most common mammalian sources – primates, rats, carnivores, ungulates, and bats-derived viruses – have been found to be the most viral in humans.

Bats are a diverse group, with more than 1,400 species roaming each continent except Antarctica. But what most people have in common is adaptation that allows them to carry a virus that is deadly to humans and livestock when they exhibit minimal symptoms – meaning they can travel quickly and spread the virus instead of getting into trouble. Will be able to.

The secret is that bats have an unusual immune system and that is related to their ability to fly, said Raina Florat, an epidemiologist who studied bats at Montana State University.

Incredible energy is required to get off the ground and sustain flight, with the bat’s metabolic rate increasing sixteen times, Plorite said. “You would expect it to damage the cell with metabolic exertion.”

But that doesn’t happen. Instead, bats are remarkably resilient, inhabiting many species Over 30 years – unusual for such small mammals.

Mild and other bat scientists believe that evolutionary tweaks, which help bats recover from flight stress, give them extra protection against pathogens.

Arinjay Banerjee, a virologist at McMaster University in Canada, said: “Bates seems to have developed the collateral advantage of aircraft – resistance to dealing with some of the nestiest viruses known to science.”

While scientists are still unraveling the mystery, the two leading theories are that Batterjee can strictly regulate what he calls “efficient DNA repair mechanisms” or the triggers of inflammation in his body and not over-react to viral infections.

Examining the secrets of the bat’s immune system could help scientists understand more about when the bat virus arrives, as well as provide clues for possible future medical treatment strategies, he said.

Bats and other animals that carry pathogens do not naturally pose a threat to humans – unless conditions are right for a spillover event. “The virus comes out of the host to infect us,” said Cara Brooke, a disease ecologist at the University of California, Berkeley.

The bad news: increasing destruction And fragments of habitats around the world – especially biodiversity areas such as tropical forests – That means “we’re seeing higher rates of contact between wildlife and humans, creating more opportunities for spillovers.”

That’s why Brazilian researchers chose Pedra Branca Park. As one of the largest forests in the world located in an urban area, it offers constant interaction of wild animals with thousands of humans and domestic animals in the surrounding communities. Scientists have confirmed the COVID-19 case of not only bats, but also small primates, wild cats and domestic cats in homes.

Ian Mayke, a virologist at the University of Queensland in Australia, said scientists and governments would have a better chance of a future outbreak if they were told when and where to start.

“Ongoing, continuous, nonstop surveillance” along with lines of flu labs by the World Health Organization could help better prepare researchers, he said. He also suggested that virus detection labs could regularly sample wastewater or materials discharged from hospitals.

In India, a national mission on biodiversity and human well-being is pending from 2018 and is likely to be launched next year. Abi Tamim Wanak, a conservation scientist at the Ashok Trust for Research in Ecology and Environment in Bengaluru, said the main part of the plan is to set up 25 sandinale surveillance sites across the country in both rural and urban areas.

“They will be the first line of defense,” he said.

Various patchwork of virus surveillance programs exist in different countries, but due to the political climate and the sense of urgency the funding is waxed.

One of the most ambitious endeavors is the Global Warm ProjectIs, which aims to find 500,000 new viruses in 10 years.

U.S. for International Development The agency recently announced million 100 million stop spillover start The project, an effort led by scientists from Tufts University and global partners to study zoonotic diseases in Africa and Asia.

One approach, scientists say, will not help, considering bats an enemy – defaming them, throwing stones or trying to burn them out of caves.

This spring, in you, the villagers of the Indian state of Rajasthan identified bat colonies in abandoned forts and palaces and killed hundreds with bats and bats and sticks. They also effectively trapped and sealed some crevices where the bats lived. In the Indian state of Karnataka, villagers cut down old trees where bats roost.

Scientists say those tricks could be fired later.

Check After the US Centers for Disease Control and Prevention and Ugandan health officials found that mining operations had attempted to destroy bats from Ugandan caves, the remaining bats showed higher rates of Marburg virus infection. This led to the most severe outbreak of Marburg hemorrhagic fever in Uganda in 2012.

Vikram Mishra, a virologist at the University of Saskatchewan in Canada, said stress is a major factor in disrupting the natural balance created by bats – the more you push the bats, the more they spread the virus.

Although the complete ban on wildlife killings by Indian forest officials and orders to repeat the information campaign to remove the myths were largely successful, persuading people not to attack bats means removing long-standing cultural assumptions.

“People have a lot of misconceptions about bats. They are nocturnal and see a little strange flying, and there is a lot of literature and culture built around bats becoming scary, “said Hannah Kim Frank, a university biologist at Tulane University.” But bats are not aggressive – and attacking bats helps control diseases. Not. “

Bats also play an important role in ecosystems: they feed on insects like mosquitoes, pollinate plants like amulets and spread seeds.

“We really need bats in the wild that consume organisms that destroy the cotton, corn and pecan harvests,” said Kristen Lear, an ecologist at Bat Conservation International.

A better approach to reducing the risk of disease, Frank said, is simply to reduce contact between wild bats and people and livestock.

She suggested that while migrating bats, and researching when new puppies are born, people can make decisions about when to avoid certain areas or keep their livestock pens.

In North America, some scientists advocate banning public access to caves where people live.

Kate Langwig, an infectious disease ecologist at Virginia Tech, said, “Cave getting – bat-friendly gates, made of iron crossbars – can keep humans out and allow bats to move freely. “If we leave the bats alone, and don’t try to hurt them or spoil them, they’ll be healthy.”

The most significant factor in bringing bats into constant contact with people and domestic animals is habitat destruction, forcing bats to acquire new fodder and scattered grounds.

Australia In Australia, the widespread destruction of winter-flowering eucalyptus trees, which provide nectar for fruit bats – locally known as “flying foxes” – encourages bats to move to areas close to human settlements, including Hendra’s Brisbane para. Is.

There, bats transmit the virus to horses, which in turn infect infected people. It was first identified in 1994 and is called the Hendra virus, It is very deadly, 60% of people and 75% of horses became infected.

Similar incidents occurred in Bangladesh, when fruit bats were taken to cities due to habitat destruction, where they spread the Nipah virus, Which causes severe encephalitis in humans by licking palm juice From storage barrels.

To counteract the potential bat movement, Montana State University’s Plurite and Australia-based colleagues are studying restoration. Bat native habitat.

“Every city in Australia is full of fruit bats losing their winter habitat,” he said. “The idea is to plant new forests and make sure they are away from places with pets and people.”

Whether the goal is to control the spread of known zoonotic diseases or to reduce the risk of newcomers entering as epidemics, the strategy is the same: reducing contact between humans and wild animals.

“In the history of COVID-19s, bats have suffered more than prey,” said Ricardo Moretelli, coordinator of the Fiocruz project in Brazil. “Bats host large numbers of parasites, and they deal well with these parasites. The problem is when humans come in contact with them. “


Lars reported from Washington. Silva de Sosa reported from Rio de Janeiro. Ghosal reports from New Delhi.


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