New Delhi, 27 May 2025: In a chilling warning, the World Health Organization (WHO) and researchers from the University of Manchester have raised global alarm about the rising threat of Aspergillus fumigatus — a killer fungus that could become far more dangerous due to climate change. New research predicts that this deadly pathogen, which currently causes life-threatening infections in vulnerable individuals, may expand its geographic reach across Europe by up to 77% by the year 2100, putting millions more at risk.
Aspergillus Fumigatus: A Silent Killer With Up to 85% Fatality Rate
Aspergillus fumigatus a common species of fungus found in soil, decaying plant matter, and even indoor environments. Although harmless to most healthy people, it can be deadly when inhaled by individuals with weakened immune systems. Such as cancer patients, transplant recipients, and those with chronic lung conditions like asthma and cystic fibrosis.
The most severe form of infection caused by this mold is known as invasive aspergillosis. which can result in organ failure, particularly of the lungs. According to experts, this infection carries a mortality rate ranging from 40% to 85%, depending on how quickly it is diagnosed and treated.
Climate Change Could Expand the Fungus’s Reach by 77% by 2100
The recent study, conducted by scientists at the University of Manchester and published in the journal Nature Microbiology, reveals that the continued rise in global temperatures is creating more hospitable environments for A. fumigatus. If current climate trends continue, the fungus is projected to expand its range in Europe by 77%, potentially exposing an additional 9 million people to infection risk.
This shift would allow A. fumigatus to colonize areas previously considered too cold or inhospitable for fungal survival, turning large swaths of the continent into potential danger zones.
Aspergillus Flavus Also Poised to Spread and Threaten Food Security
The study also evaluated another member of the Aspergillus genus: Aspergillus flavus. Unlike A. fumigatus, which causes respiratory infections, A. flavus best known for producing aflatoxins — toxic compounds that contaminate crops like maize, peanuts, and tree nuts.
Aflatoxins are highly carcinogenic and pose a severe threat to agricultural productivity and food safety. The researchers estimate that A. flavus could expand its range by 16% across Europe. Potentially contaminating crops and increasing exposure to these harmful toxins for more than one million additional people.
Immunocompromised Patients at Highest Risk of Fungal Infections
According to WHO and leading experts, the populations most at risk include people with compromised immune systems. This includes:
- Cancer patients undergoing chemotherapy
- Organ transplant recipients
- Individuals with HIV/AIDS
- Patients with chronic respiratory diseases such as asthma and COPD
- People receiving corticosteroid treatments
In these individuals, fungal spores that are normally harmless can lead to aggressive and invasive diseases, often spreading rapidly through the lungs and bloodstream.
Symptoms Often Misdiagnosed: The Danger of Delayed Detection
One of the critical challenges with diagnosing Aspergillus fumigatus infections is that the initial symptoms — cough, fever, shortness of breath — closely mimic common viral or bacterial infections, including COVID-19 and the flu. This leads to frequent misdiagnosis or delayed treatment, which can drastically worsen outcomes.
Compounding the problem is the increasing resistance to antifungal drugs. The limited number of effective antifungal treatments available is dwindling, making the battle against invasive fungal infections even more difficult.
WHO Flags Aspergillus as a Priority Pathogen
In response to the growing threat, the World Health Organization has listed Aspergillus fumigatus and Aspergillus flavus among its high-priority fungal pathogens, emphasizing their global impact and resistance to treatment.
Dr. Norman van Rhijn, lead researcher of the Manchester study, warned that fungal pathogens have historically neglected in public health conversations despite being just as deadly as many bacterial or viral infections. He highlighted the parallels with the recent emergence of Candida auris. Another multidrug-resistant fungus believed to have proliferated due to climate change.
“As the planet warms, we are going to see more pathogens spread across continents,” he said. “Fungi are no exception — and their impact on human health will only intensify if we don’t act now.”
Urgent Need for Global Monitoring and Antifungal Innovation
Experts now say that the time has come to treat fungal diseases with the same urgency as viral pandemics. The study’s authors and WHO officials are calling for:
- Greater investment in antifungal drug development
- Increased research into early detection methods
- Robust surveillance of fungal pathogens
- Stronger awareness campaigns for healthcare providers
Public health authorities are also urging hospitals and clinics to develop fungal screening protocols, especially for high-risk patients.
Final Warning: Climate Change and Fungi Form a Lethal Combination
The growing spread of Aspergillus fumigatus is yet another example of how climate change is not just an environmental crisis but a looming public health emergency. As temperatures rise and ecosystems shift, once-rare pathogens are gaining a foothold in new territories — with potentially deadly consequences.
Without immediate intervention, the silent spread of these killer fungi could affect millions more. Overwhelming healthcare systems and leading to a surge in preventable deaths.
