Fungal pathogens are becoming more common. This isn’t a reference to The Last Of Us, but a reflection of how human activity is altering the climate, and this is leading to new patterns of fungi and, in some cases, the appearance of pathogenic fungi in previously unrecorded locations. Scientific estimates suggest there are between 2.2–3.8 million or more fungal species exist on Earth. However, scientists have only succeeded in characterising around 146,000 of these (which suggests 96 percent of fungal species remain unknown).
Despite this lack of detail, the abundance of fungi across all ecosystems is of great importance as is examining trends for biogeographic patterns. Fungi can exist as pathogens and, in addition, the ubiquitous nature of fungi provides important clues about climate change.
The impact of climate change is significant, such as drive striking differences in carbon decomposition and soil organic matter formation between different biomes. Fungi experience considerable conversion pressures due to different human-centric activities. In association with general climate changes, there is the intensification of land use alongside growing human populations, environmental exploitation and pollution. These changes are leading to an alternation of fungal diversity in some areas, which provides information about environmental challenges.
In addition, the changing patterns are also influencing the spread of fungal pathogens that pose a risk to humans. This trend has been identified in a recent World Health Organisation review “WHO fungal priority pathogens list to guide research, development and public health action.”
The WHO report draws on research that finds more frequent extreme weather events (including heat waves, drought, and flooding) foster circumstances that favour the survival and infectivity of fungal pathogens.
Of particular concern with these trends are candidal infections, dermatophytoses, other mold infections, and deep fungal infections. Here there was clear evidence of climate sensitivity, particularly those that are emerging, spreading to new geographic regions, or both.
According to one review: “Climate change presents substantial challenges to healthcare systems worldwide. Physicians who completed their training or practice in regions where certain climate-sensitive fungal diseases were historically rare or absent may find it difficult to recognize, diagnose, and treat them.”
Data suggests that sustained higher temperatures at increasingly higher latitudes account partially for the expanding geographic ranges of the dimorphic pathogenic fungi. Natural disasters like floods, hurricanes, and drought are associated with increased incidences of specific fungal infections. The risk stemming from these infections may increase as a result of more frequent climate change-related extreme weather events.
In addition, novel climate-sensitive pathogenic fungal organisms have emerged in recent years in the setting of global warming.
Such investigations provide an important tool to researchers for understanding the epidemiological patterns underlying fungal transmission. This fraction also aids with the prediction of future outbreaks and with the adoption of effective control strategies.
