Climate change is linked to the spread of viruses like monkeypox, experts say: NPR


This photo, taken on February 24, 2014 during a Greenpeace aerial survey mission in Indonesia, shows felled trees in a forest located in the Karya Makmur Abadi concession, which was being developed for a palm oil plantation . On February 26, environmental group Greenpeace accused American consumer goods giant Procter & Gamble of helping destroy Indonesia’s rainforests.

BAY ISMOYO/AFP via Getty Images


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BAY ISMOYO/AFP via Getty Images


This photo, taken on February 24, 2014 during a Greenpeace aerial survey mission in Indonesia, shows felled trees in a forest located in the Karya Makmur Abadi concession, which was being developed for a palm oil plantation . On February 26, environmental group Greenpeace accused American consumer goods giant Procter & Gamble of helping destroy Indonesia’s rainforests.

BAY ISMOYO/AFP via Getty Images

Cases of monkeypox are on the rise in the United States, with about 67,600 cases globally, including about 25,500 in the US. At the same time, the world is still facing a pandemic of COVID-19, although the number of cases has decreased.

Researchers say these types of viruses, known as zoonotic diseases, or those that spread between humans and animals, will become more common as factors such as destruction of animal habitats and human expansion intensify in previously uninhabited areas.

Humans and animals are interacting more

Monkeypox was first found in monkeys in 1958 and in humans in 1970, according to the Centers for Disease Control and Prevention.

Factors such as deforestation, population growth and animal husbandry have removed the boundaries between the places where humans and wild animals live, resulting in in closer contact.

Since 1990, about 1 billion acres of forest have been cut. Deforestation rates have been declining, with an average of 25 million hectares cleared each year from 2015 to 2020, down from 16 million annually in the 1990s, according to a United Nations report.

In addition to the impact on the climate, deforestation means a loss of habitat that often ends up bringing wildlife closer to people.

“You’re just seeing the effects of change in the environment, change in animal behavior, change in human behavior, bringing wild animals and humans into more contact where they can have more contamination,” said Lanre Williams-Ayedun , the senior vice president of international programs at World Relief, a sustainability nonprofit.

Those that change patterns in animals Migration and reproduction can influence how pathogens behave in their natural host, possibly making them more contagious in the process, said Dr. Carl Fichtenbaum, vice chair of clinical research for internal medicine at the University of Cincinnati.

“Depending on the particular germ, when it gets a chance to do that multiple times, the germ adapts to the new species,” he said.

A United Nations study found that 60% of known infectious diseases found in humans and 75% of all emerging infectious diseases are zoonotic, or transmitted between species, from animals to humans.

Some of these include Ebola, Zika, and COVID-19, which scientists hypothesize began in bats.

Could the current monkeypox outbreak be predicted?

Monkey pox is endemic, or occurs regularly, in some African countries. But because monkeypox can be “self-limited” and not as transmissible as other viruses. “This it wasn’t something you would have thought would become such a big outbreak,” Williams-Ayedun said.

The virus was nearly eradicated at one point when people in these regions received vaccines against smallpox, a relative of monkeypox, in greater numbers. But now, vaccine rates are much lower in people 40 and younger, Williams-Ayedun said.

People are also traveling further and more often these days.

“It’s easy to spread disease globally and we’ve seen that something that happens in what we think is a remote part of the world somewhere can very easily become something that we’re concerned about where we live,” he said.

Luis Escobar, assistant professor in Virginia Tech’s Department of Fish and Wildlife, said that while researchers have been able to predict where small outbreaks of monkeypox are most likely to occur (poorer regions, areas of war or social conflict, or remote locations), it is in those places that data is less accessible .

“My perception is that the data may not be enough,” he said. “The data may not have been sufficient to anticipate a global epidemic of this magnitude.”

He added that scientists need to study zoonotic diseases “in every corner of the world because we don’t know which [region] will trigger the next pandemic.”

Fichtenbaum agrees, saying that with the thousands of germs in the ecosphere, it’s hard to know which ones are spreading to pandemic proportions.

“I think it would be very disingenuous for someone to say, ‘Well, I can predict that this germ is going to be the next big germ,'” he said. “I think we’re not very good at that, just like we’re not very good at predicting earthquakes “.

The spread of zoonotic diseases is likely to be more frequent

Escobar said that in looking to the future, researchers have neglected data from the past in their work to combat the spread of the disease.

“The research I do is kind of anticipating the future,” he said. “But we’re putting a lot of effort into trying to reconstruct the past. We’re looking at data from the last century, in terms of wildlife diseases, climate, forest laws from the last 100 years, and with that we understand what’s happening now.”

He and his colleagues have used this data in simulations to predict patterns over the next 50 to 100 years. But zoonotic diseases may not take that long.

Escobar’s research suggests that in the next 12 to 20 years, there could be a significant increase in diseases spread to humans by bats. Diseases endemic to Latin America’s bat population could begin to head south as Latin America warms, he said, affecting the distribution and quantity of bats.

Also, diseases that are unique to animals could tell us a lot about what society might be like in the future.

For example, as global warming continues to intensify, a common virus among fish could decimate aquaculture, dealing blows to food production and the economy, Escobar said.

What can be done about it?

Fichtenbaum says public policy will have to be addressed the spread of zoonotic diseases.

“I think right now, a lot of the focus on climate change has been, ‘Well, this is bad for the environment, and we’re going to see floods and we’re going to see heat waves, and that can affect economic survival.’ But people don’t always look at it in terms of human health and disease, which is very costly.”

In recent years, some researchers in the zoonoses field have been pushing toward a “one health” approach, merging public health, veterinary health and environmental health, Ayedun-Wliliams said.

Helping people secure jobs, shelter and safe food is also important, as shortages can lead to the hunting of wild animals or the cutting down of trees for households, which in turn can lead to zoonotic diseases , he said.

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