Saturday September 21, 2019

Study: Global Temperatures May be Responsible for Rise of Deadly Fungal Disease

Though only 715 people in the United States have contracted the new fungal infection so far, scientists say it may be an indication of what's to come

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fungal disease, global temperatures
FILE - This undated photo shows a CDC technician making notations on culture plates in which fungal colonies had been grown. The fungus Candida auris has spread to more than 30 countries in the past decade. VOA

The first fungal disease linked to rising global temperatures may have emerged, suggests a study published in the scientific journal mBio. Though only 715 people in the United States have contracted the new fungal infection so far, scientists say it may be an indication of what’s to come.

Three unrelated variants of deadly Candida auris cropped up simultaneously in South America, Asia and Africa, and it has spread to more than 30 countries in the past decade.

The fungus, which is difficult to treat, can be life-threatening in people with weakened immune systems. The U.S. Centers for Disease Control and Prevention (CDC) said C. auris has been found to be resistant to all three of the most common antifungal drugs, and more than a third of people afflicted with invasive cases of the fungus die.

Mild fungal maladies like athlete’s foot are common, but severe fungal infections are relatively rare in healthy individuals. We are guarded from fungal infections by our strong immune systems and high body temperatures. Knock down one or both of those protective pillars, however, and humans start to look like a good host for opportunistic fungi.

Dr. Arturo Casadevall, a microbiology professor at Johns Hopkins University and lead author of the paper, suggested nearly 10 years ago that fungi would become more heat-tolerant as Earth became warmer, causing humans to lose the advantage that our high body temperatures provide. He said C. auris may be the first example — and it’s unlikely to be the last.

fungal disease, global temperatures
U.S. public health officials are urging doctors and nurses around the world to be on the lookout for a highly drug-resistant yeast strain called Candida auris. (Photo courtesy of CDC). VOA

Heat-tolerant fungus

The researchers compared the heat tolerance of C. auris to that of similar species. While most of the species they considered don’t multiply above 35-37°C (95-98.6°F), C. auris can survive temperatures of up to 42°C (107.6°F).

That’s a problem for people because “we have very little ability [to adapt],” said Casadevall. “We can’t raise our temperature and walk around with a high fever all the time. But these organisms have the capacity to adapt to change, and for them, this change is happening gradually, because they can replicate every couple of hours.”

Alone, C. auris’ tolerance of high temperatures isn’t enough to prove that its rise is the product of climate change, since it isn’t clear how long ago the fungi developed their resistance to high temperatures. The researchers acknowledge that climate change is likely just one of many factors that led to its emergence.

“When it comes to the origins of Candida auris, it’s a complete mystery about where it came from still,” said Dr. Brendan Jackson, leader of the epidemiology team of the CDC’s fungal diseases branch, who was not involved with the research. “It’s clear there are huge environmental changes going on in the world, and for a fungal organism that has just come onto the scene within the last decade in multiple places in the world, it does make you think that something could be happening on a large environmental scale.”

In order to determine how large a role climate change played, the researchers suggest more careful analysis of C. auris’ ability to tolerate high temperatures. For example, if early outbreaks are less heat-tolerant than later outbreaks, that could indicate that the fungi are rapidly adapting to warmer temperatures.

Fungal disease
Fungus can impair the immune system. Pixabay

Looking ahead 

Casadevall noted that C. auris has mostly affected people with weakened immune systems, which could mean that while the fungus has adapted to high temperatures, it still isn’t very good at infecting people. On the other hand, he added, it’s possible that there are other fungi that are highly infectious but can’t grow in higher temperatures yet.

If climate change created one new infection, Casadevall said, “we can’t prevent it from happening again. This is likely something that humanity is going to have to deal with. I do think that we could be better prepared if there were more monitoring of fungal diseases, more research into how fungi cause disease and more antifungal drugs.”

ALSO READ: Many US Cities Lack Data to Measure Greenhouse Emissions Progress: Report

Jackson said the CDC has increased its efforts to inform the public about the seriousness of fungal infections, and new antifungal drugs are under development. Despite the increasing number of cases around the world, he emphasized that there’s no cause for alarm since C. auris poses little to no threat to healthy individuals.

“There’s a lot of fear that comes with an emerging pathogen like this,” said Jackson. “But this is affecting the sickest of the sick. I think it’s something to be on top of, but the average person does not need to be concerned about this in their daily life.”  (VOA)

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The Mayors Announce Their Support For Climate Change Strike

The Mayors of Paris, New York, Los Angeles and Copenhagen on Friday announced their support for the global climate strike

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mayors, worldwide, climate change, strike
We have an opportunity to show, not only that we hear their message, but that they have inspired us to act even faster. Pixabay

The Mayors of Paris, New York, Los Angeles and Copenhagen on Friday announced their support for the global climate strike.

“Today, September 20th, these inspiring young leaders have called for adults to join them for a global climate strike. We have an opportunity to show, not only that we hear their message, but that they have inspired us to act even faster,” they said in a joint statement.

“As mayors, our greatest responsibility is to protect the lives and wellbeing of those that live in our cities. As adults, our obligation is to leave the world in a better state for our children than we inherited it,” they said.

“That is why we are supporting the global climate strike. Mayors around the world, working through C40 Cities, are committed to deliver on the Paris Agreement and taking action to peak their emissions as our cities already have and bring them down sharply by 2030.

“Many businesses, investors, labour groups, faith leaders and local communities share our urgency…Young people are telling us that the climate emergency demands an emergency response. We couldn’t agree more,” the Mayors added.

mayors, worldwide, climate change, strike
C40 Cities connects 94 of the world’s greatest cities to take bold climate action, leading the way towards a healthier and more sustainable future. Pixabay

They are the Mayor of Paris and Chair of C40 Cities, Anne Hidalgo; Mayor of New York City, Bill de Blasio; Mayor of Los Angeles, Eric Garcetti; and Lord Mayor of Copenhagen, Frank Jensen.

Following next week’s UN Climate Action Summit, these four leaders will be among 70 plus Mayors committing to more ambitious climate action at the C40 World Mayors Summit in Copenhagen on October 9-12.

ALSO READ: How Often You Exercise Depends on Your Personality

C40 Cities connects 94 of the world’s greatest cities to take bold climate action, leading the way towards a healthier and more sustainable future. (IANS)