New findings presented at the annual meeting of the American Society for Microbiology suggest increased levels of fungal spores in the air are strongly linked to surges in cases of influenza and COVID-19.
The study was based on daily spore samples taken in 2022 and 2024 in San Juan and Caguas, Puerto Rico, where fungal spores and pollen are endemic and present year-round. The data on spores was matched to data on the daily incidence of people diagnosed with COVID-19 and flu.
The researchers found increases in fungal spore counts matched surges in flu and COVID activity. There was no relationship between pollen levels and respiratory illness activity.
The findings from our study suggest that monitoring airborne fungal spore levels could help predict short-term outbreaks (spikes) of flu and COVID-19.
“The findings from our study suggest that monitoring airborne fungal spore levels could help predict short-term outbreaks (spikes) of flu and COVID-19, giving public health systems an early warning signal,” study author Felix Rivera-Mariani, PhD said in a press release from the American Society of Microbiology. “Our findings also highlight the potential role of environmental factors—not just person-to-person spread—in contributing to the incidence of respiratory viral infections. That could open new doors for targeted public health alerts, especially in areas with high outdoor airborne fungi.”
The authors said the findings may help develop environmental risk alerts, particularly for vulnerable populations like the elderly, or those with asthma.