New diseases transmitted from animals to humans could destroy humanity

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New diseases transmitted from animals to humans could destroy humanity
New diseases transmitted from animals to humans could destroy humanity
Anonim

The author reminds us of a disease called Ebola, which was recently considered the number one threat to humanity. Although covid-19 has distracted attention from the disease, it is killing people in Africa. The risk of new diseases transmitted from animals to humans is also high. Environmental measures can help, but they cost $ 30 billion.

The doctor who discovered Ebola warns that deadly new viruses could emerge from the Congo rainforest.

Kinshasa, Democratic Republic of the Congo - A patient with early symptoms of hemorrhagic fever sits quietly on her bed, holding back two toddlers desperate to escape a prison cell-like hospital ward in the provincial town of Ingende in the Democratic Republic of Congo.

They are awaiting the results of the Ebola test.

The patient can communicate with her relatives only through a transparent plastic viewing window. Her name is kept secret, so that the woman is not persecuted by the local population frightened by Ebola. The children were also tested, but they have no symptoms yet.

There is a vaccine for Ebola, there are drugs for the disease, and this has helped reduce the number of deaths.

But everyone secretly thinks about one thing. What if this woman doesn't have Ebola? What if this is Patient X Zero? And disease X is here called the infection of a new pathogen that could sweep the world as quickly as COVID-19? Moreover, this disease has the same mortality rate as Ebola - from 50 to 90 percent.

This is not science fiction. It is scientific fear based on scientific evidence.

“We all need to be afraid,” says Dadin Bonkole, the attending physician of the Ingende patient. - Ebola was unknown. Covid was unknown. We must be wary of new diseases."

Threat to humanity

Humanity is facing an unknown number of new and potentially deadly viruses emerging from the tropical rain forests of Africa, says Professor Jean-Jacques Muyembe Tamfum. This man participated in the identification of the Ebola virus in 1976 and has been searching for new pathogens since then.

“More and more pathogens will appear in our world,” he told CNN. "And this is a threat to humanity."

As a young scientist, Muembe took the first blood samples from victims of a mysterious disease that caused bleeding and killed about 88% of patients, as well as 80% of the medical staff working at Yambuku Hospital, where it was first discovered.

Tubes of blood were sent to Belgium and the United States, and the scientists there found a virus in the form of a worm in the samples. They named it "Ebola" after a river close to the site of the outbreak in what was then Zaire.

An entire network has been created to identify Ebola, linking remote areas of the African rainforest to cutting-edge Western laboratories.

Today, the West is forced to rely on African scientists from the Congo and elsewhere, counting on them to become the frontline guardians of future diseases.

In England, the fear of a deadly new virus is very high, even after the recovery of a patient who had Ebola-like symptoms. Samples taken from her were checked on the spot and sent to the National Institute for Biomedical Research (INRB) in Kinshasa, where they were analyzed for other diseases with similar symptoms. All tests gave a negative result, and the disease that struck the woman remained a mystery.

Giving an exclusive interview to CNN in the capital of the DRC, Kinshasa, Muembe said that new zoonoses, as infections transmitted from animal to humans are called, should be expected. These include yellow fever, various forms of influenza, rabies, brucellosis, and Lyme disease. Rodents and insects often become carriers of the disease. They have caused epidemics and pandemics before.

HIV originated from a certain species of chimpanzee and mutated to become a modern plague on a global scale. The viruses of SARS, Middle East respiratory syndrome and covid-19, which is known as SARS-CoV-2, are all coronaviruses that have passed to humans from unknown reservoirs of the animal world. This is what virologists call the natural hosts of viruses. COVID-19 is believed to have originated in China, possibly in bats.

Does Muembe think that pandemics of the future will be worse than COVID-19, more apocalyptic? “Yes, yes, I think so,” he replies.

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Hospital COVID-19 in City Clinical Hospital No. 15 named after O. Filatov

New viruses on the rise

Since the first animal-to-human infection (yellow fever) was discovered in 1901, scientists have found at least 200 more viruses that cause disease in humans. According to a study by Professor Mark Woolhouse, who studies infectious epidemiology at the University of Edinburgh, scientists find three to four viruses every year. Most of them are carried by animals.

Experts say the rise in the number of new viruses is a result of the destruction of the ecological environment and the trade in wild animals.

When animals lose their natural habitat, large animals die out, and rats, bats and insects survive. They can live near a person and often become carriers of new diseases.

Scientists have linked past Ebola outbreaks to human invasion of tropical rainforests. In one 2017 research paper, scientists took satellite imagery and determined that 25 of the 27 Ebola outbreaks in the tropical rainforests of western and central Africa between 2001 and 2014 began in areas where trees had been felled two years earlier. They also found that outbreaks of natural focal Ebola occurred in areas of high population density and where conditions were favorable for the virus. But the significance of deforestation was almost independent of these factors.

In the first 14 years of the 21st century, rainforests in the Congo Basin were cleared in an area the size of Bangladesh. The United Nations warns that if deforestation and population growth continue, rainforests in the DRC could disappear completely by the end of the century. In this case, the animals living there and the viruses they carry will more often encounter a person, causing new, often catastrophic consequences.

It doesn't have to be that way.

A multidisciplinary team of scientists from the United States, China, Kenya, and Brazil has calculated that spending $ 30 billion a year on projects to protect rainforests, stop wildlife trade and farming will be enough to stave off future pandemics.

The group wrote in Science magazine that spending $ 9.6 billion a year to protect forests around the world will result in a 40 percent reduction in deforestation in areas where transmission of the virus to humans is greatest. We need to create new incentives for people living in forests and making money from them. The large-scale felling of trees and the commercialization of the wildlife trade must be banned.

In Brazil, a similar program was carried out, and thanks to it, between 2005 and 2012, deforestation there decreased by 70%.

It may seem like $ 30 billion a year is too much. However, scientists argue that these costs will pay off quickly. The coronavirus pandemic will cost America alone in the coming years about $ 16 trillion, according to Harvard economists David Cutler and Larry Summers, former Treasury Secretary. The IMF estimates that production losses due to the pandemic will amount to $ 28 trillion between 2020 and 2025.

Early warning system

Today Muembe runs the National Institute for Biomedical Research in Kinshasa.

Some scientists still sit in cramped rooms in the old INRB site, where Muembe began working on Ebola. But in February, new institute laboratories were also opened. INRB is supported by Japan, the United States, the World Health Organization, the EU, and other foreign donors, including nongovernmental organizations, foundations and academic institutions.

Biosafety Level 3 laboratories, genome sequencing equipment, and world-class equipment are not charitable donations. These are strategic investments.

With the support of the US Centers for Disease Control and Prevention and the World Health Organization, these INRB laboratories have become an international early warning system for new outbreaks of known diseases such as Ebola and, more importantly, for those diseases that have not yet been discovered.

“If a pathogen emerges from Africa, it will take time for it to spread throughout the world,” says Muembe. “And if the virus is detected early on, as my institute is doing here, Europe [and the rest of the world] will have the opportunity to develop new strategies to combat these pathogens.”

Muembe has forward outposts leading the front line for reconnaissance and search for new pathogens. Doctors, virologists and scientists are working deep in the DRC to identify known and unknown viruses before they can trigger a new pandemic.

Simon Pierre Ndimbo and Guy Midingi are ecologists hunting for viruses in the northwestern Equatorial province of Ingende. They are at the forefront of this quest, watching for signs of new infectious diseases.

On a recent expedition, these researchers captured 84 bats by carefully removing these squeaking and biting animals from their nets and placing them in their bags. “We must proceed with caution. If you're careless, they'll bite,”explained Midingi, who wore two pairs of gloves to protect him. A single bite from a bat may be enough for a new disease to spread from animal to human.

Ndimbo says that they primarily look for signs of Ebola infection in bats. The last outbreak of the disease in Equatorial Province was due to person-to-person transmission, but there is also a new strain that is believed to have emerged from a forest reservoir. And no one knows what kind of reservoir it is, and where it is located.

In a laboratory in Mbandaka, swabs and blood samples are taken from mice. They are tested for Ebola and then sent to INRB for further testing. After that, the bats are released.

In recent years, dozens of new coronaviruses have been found in bats. Nobody knows how dangerous they are to humans.

How a person first contracted Ebola remains a mystery. But scientists believe zoonoses like Ebola and covid-19 jump onto humans when wild animals are slaughtered.

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A nine-year-old woman from Monrovia mourns her mother, who died of Ebola. Liberia, Oct 2, 2014

Bushmeat is a traditional source of protein for rainforest people. But now it is sold very far from hunting grounds, and is also exported all over the world. The UN estimates that five million tons of game are removed from the Congo Basin every year.

In Kinshasa, a market vendor displays a smoked colobus monkey carcass. The animal's teeth are bared in a terrible, lifeless grin. The seller asks for $ 22 for a small primate, but declares that it is possible to bargain.

In some parts of the DRC, colobuses have been almost completely wiped out, but the trader says he can export them to Europe by plane in large numbers.“To be honest, these monkeys are not allowed to be sold,” he explains. "We have to cut off their heads and arms and pack them with other meat."

According to the trader, he receives carcasses every week, and some of the game comes from Ingende, about 650 kilometers upstream of the river. This is the same town where doctors live in constant fear of a new pandemic.

Conserv Congo director Adams Cassinga, who investigates crimes against wildlife, said that “Kinshasa alone exports between five and 15 tons of game, with some going to North and South America. however, most of it ends up in Europe. According to him, the main recipients are Brussels, Paris and London.

Smoked monkeys, soot-covered python chunks, fly-infested ham of the sitatunga water antelope make a terrible impression. But they are unlikely to contain dangerous viruses, because they die during heat treatment. True, scientists warn that even cooked primate meat is not entirely safe.

Live animals from the market are much more dangerous. Here you can see young crocodiles with their mouths wrapped in a rope and tied paws, wriggling, lying on top of each other. Vendors offer giant earthen snails, land turtles and freshwater turtles that are stored in barrels. There is also a black market that sells live chimpanzees, as well as more exotic animals. Someone buys them for private collections, and someone sends them to the pan.

"Disease X" may be hiding in any of these animals, which are brought to the capital by the poor, serving the rich people who are hungry for exotic meat and pets.

“Contrary to popular but mistaken beliefs, game here in cities is not for the poor, but for the rich and privileged. There are senior officials who believe that eating a certain type of game will give you strength,”Cassinga said. “There are people who see game as a status symbol. But in the last 10-20 years, we have seen an influx of expats, mainly from Southeast Asia, who require the meat of very specific animals, for example, turtles, snakes, primates."

Scientists have previously linked these live animal markets to zoonoses. This is where the H5N1 virus, known as bird flu, and the SARS virus came from. The exact origin of the coronavirus that causes Covid-19 has not been confirmed. But more often than not, scientists suspect that the source was such markets where live animals are sold and slaughtered for meat.

The commercialization of the wildlife trade is a potential route for infection. It is also a symptom of the destruction of the Congo rainforest, which is the second largest in the world after the Amazon jungle.

Most of the tree felling is done by local farmers, for whom the forest is a source of prosperity. 84% of felling areas are small farms. But slash-and-burn agriculture, which the local population is engaged in, brings people closer to the wild animals living in this once virgin territory, and this creates a serious danger associated with the spread of disease.

“If you attack a forest, you change the environment. Insects and rats leave these places and come to villages … this is how they transmit viruses, including new pathogens,”says Muembe.

And at the Ingende hospital, doctors wear maximum personal protective equipment. These are glasses, yellow overalls for biological protection, double gloves tightly wrapped with tape, transparent hoods on the head and shoulders, galoshes for shoes, complex face masks.

They are still worried about the Ebola patient who turns out to have no Ebola. But it could be a new virus, it could be one of those many diseases that are already known to science. But no analysis has explained why she has a high fever and diarrhea.

“There are cases that are very similar to Ebola, and then we do the tests, and they come back negative,” says Dr. Christian Bompalanga, head of medical services at Ingende.

“We have to do more research to understand what's going on … We have two suspicious cases here at the moment,” he adds, pointing to the isolation ward where a young woman with children is being treated. Several weeks have passed, and there is still no exact diagnosis of her illness.

When a new virus begins to circulate among humans, the consequences of short contact at the edge of the forest or in the live animal market can be disastrous. This was shown by covid-19. Ebola proved it. The authors of most scientific publications proceed from the assumption that if humanity continues to destroy the natural habitat of animals, more and more infectious diseases will appear. It's just a matter of time.

The solution to the problem is clear. Protect forests to save humanity. Indeed, Mother Nature has many deadly weapons in her arsenal.

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