Deadly fungus Aspergillus fumigatus spreads across the U.S. due to climate change
22nd June 2025 – (San Francisco) A lethal fungus known as Aspergillus fumigatus is rapidly spreading throughout the United States, raising serious health concerns among experts as climate change exacerbates its growth. This fungus can rot human tissue from within, leading to severe lung infections called aspergillosis, particularly in vulnerable populations such as cancer patients, individuals with asthma, and those living with HIV.
Aspergillus fumigatus is airborne, with spores so minuscule that they are easily inhaled without notice. Infections can lead to organ failure and death, particularly in those with weakened immune systems. Regions such as Florida, Louisiana, Texas, Georgia, and California have reported the highest levels of exposure, largely due to their warm, humid climates and agricultural activities. Major urban centres like New York, Houston, and Los Angeles are also at increased risk due to dense populations and aging infrastructure.
Currently, aspergillosis is not classified as a reportable disease in the U.S., making it challenging to track the number of infections, hospitalizations, and related fatalities. Health officials recommend that at-risk individuals avoid environments with soil, mould, and dust, while hospitals have begun enhancing their mould inspection and antifungal protocols.
The World Health Organization (WHO) recognises Aspergillus fumigatus as a “critical priority” fungal threat due to rising drug resistance and high mortality rates. The fungus thrives in warm, damp conditions, and studies suggest that climate change is facilitating its survival, potentially expanding its range by over 75% by 2100 if current fossil fuel consumption continues.
Experts warn that the overuse of azole drugs in agriculture, which are also used to treat human infections, may lead to drug-resistant strains that can transfer from the environment to humans. This complicates treatment options and heightens the urgency for investment in new antifungal therapies and improved healthcare training.