It’s more or less like in the series The Last of Us. But here’s really real life – and scientists even think the series can help the world prepare
Fungi causing infections responsible for millions of deaths a year will spread significantly to new regions as the planet warms, provides a new investigation-and the world is not prepared.
The fungi are absolutely everywhere. A vast kingdom of organisms, from mold to mushrooms, grow in environments such as soil, compound and water. They play an important role in ecosystems, but they can play a devastating impact on human health: fungal infections kill about 2.5 million people a year and the lack of data means that this number can be much higher.
However, we are still far from understanding them, especially as these incredibly adaptable organisms will respond to global warming.
A team of scientists at the University of Manchester has used computational simulations and predictions to map the future propagation of Aspergillus, a common group of fungi found worldwide that can cause aspergillosis, a potentially fatal disease that mainly affects lungs.
Scientists have found that certain species of Aspergillus will expand its distribution area as the climate crisis intensifies, advancing to new parts of North America, Europe, China and Russia. The study, published this month, is currently being reviewed by peers.
“Fungi are relatively little investigated compared to viruses and parasites, but these maps show that fungal pathogens will likely affect most areas of the world in the future,” says Norman Van Rijn, one of the study authors and researcher of climate change and infectious diseases at the University of Manchester.
This field of investigation has gained new attention thanks to HBO’s popular television series “The Last of Us”, which accompanies people trying to survive a world where an infectious mutant fungus has turned most of the population into violent monsters (HBO and CNN are part of the same group, Warner Bros. Discovery).
It’s fiction, says Van Rijn, but this researcher expects the series to increase the visibility of fungal infections that are killing millions of people in reality.
Aspergillus fungi grow like small soil filaments around the world. Like almost every fungi, they free a large number of tiny spores that spread throughout the air.
Human beings inhale spores every day, but most people have no health problems; The immune system eliminates them.
The story is different for those with pulmonary diseases, including asthma, cystic fibrosis and COPD (chronic obstructive pulmonary disease), as well as people with committed immune systems, such as cancer patients and organ transplanted, and those who had severe flu or Covid-19.
If the body’s immune system cannot eliminate spores, the fungus “begins to grow and basically devour us inside to be very frank,” says Van Rijn.
Aspergillosis has very high mortality rates, between 20% and 40%, said the investigator. It is also very difficult to diagnose, as doctors do not always have it in mind and patients usually have fever and cough, symptoms common to many diseases.
Pathogenic fungi are also becoming increasingly resistant to treatment, adds Van Rijn. There are only four classes of antifungal drugs available.
All of this is bad news, as climate change open new areas for Aspergillus to colonize.
Aspergillus flavus, a species that tends to prefer warmer and more tropical climates, can increase its spread by 16% if humans continue to burn large amounts of fossil fuels, a study concluded. It is expected to advance to parts of North America, northern China and Russia.
This species can cause serious infections in humans and is resistant to many antifungal medications. It also infects a variety of eating crops, representing a potential threat to food security. The World Health Organization added Aspergillus Flavus to its critical group of fungal pathogens in 2022 due to its impact on public health and the risk of resistance to antifungals.
Aspergillus fumigatus, which prefers more temperate climates, is expected to spread north toward the north pole as global temperatures increase. Its spread can increase 77.5% to 2100, according to the study, potentially exposing nine million people in Europe.
On the other hand, temperatures in some regions, including sub-Saharan Africa, can become so high that they will no longer be hospitable for Aspergillus fungi. This can bring their own problems as fungi play an important role in ecosystems, including healthy soils.
In addition to expanding the growth area of the fungus, global warming may also be increasing the tolerance of fungi to temperature, allowing them to survive better within the human body.
Extreme climate events such as droughts, floods and heat waves can also affect fungi, helping to spread spores from long distances. There were peaks of fungal diseases after natural disasters, such as the outbreak after the 2011 tornado in Joplin, Missouri.
The new study on Aspergillus “says, rightly, the threat of the fungi that inhabit our natural environment and how poorly prepared we are about to deal with the changes in its prevalence,” says Elaine Bignell, codirer of the MRC Center for Medical Micology at the University of Exeter, which did not participate in the investigation.
However, there are still many uncertainties and much research work to be done, stresses Elaine Bignell.
Despite the deadly nature of aspergillosis, there is a real lack of data about where the pathogen is in the environment and who is infected, says Justin Remais, professor of environmental health sciences at UC Berkeley, who did not participate in the investigation.
Justin Re -leading is leading a study with more than 100 million patients in the United States that has identified more than 20,000 aspergillosis cases between 2013 and 2023. The number of cases is increasing about 5% per year, he reveals.
“Fungal pathogens are becoming increasingly common and resistant to treatment and we are just starting to understand how climate change are contributing to it,” review Justin Reisters.
People are used to hearing about diseases caused by bacteria, viruses and parasites, but much less fungal diseases, says Bignell. “There is a desperate need to reverse this trend, given lethality. Any of us can be affected in the future.”
