Climate change is not only altering our weather patterns; it’s also reshaping the risk of infectious diseases. A recent Europe-wide study delved into the prevalence of pathogenic microbes in birds and bats across various climates, shedding light on the intricate relationship between climate and disease transmission.
The study, which compiled data on over 75 pathogenic microbes in nearly 400 bird species and 40 bat species, revealed a compelling connection between climate conditions and the prevalence of these disease-causing agents. Protozoans, bacteria, and viruses that can be harmful to both humans and domestic animals were the focus of this comprehensive research.
Lead author Yanjie Xu, affiliated with the Finnish Museum of Natural History at the University of Helsinki, explains, “In general, the occurrence of pathogenic bacteria increased in areas with a warm and dry climate. On the other hand, pathogenic viruses prefer a moist climate.”
This preference for specific climates extends to individual pathogens. The study examined 17 pathogen taxa with the most robust data, unveiling intriguing associations between climatic factors and disease prevalence.
Temperature was positively associated with the occurrence of avian flu virus, malaria parasites, and bacteria responsible for diseases like chlamydia, salmonella, Q-fever, and typhus in both birds and bats,
notes university lecturer Arto Pulliainen from the University of Turku Institute of Biomedicine.
Rainfall, on the other hand, exhibited both positive and negative correlations with pathogen occurrence. For example, increased rainfall raised the likelihood of Usutu, Sindbis, and avian flu viruses appearing, as well as the presence of salmonella bacteria.
“Usutu and Sindbis viruses are transmitted by mosquitoes, and rainfall can boost the prevalence of the wetlands where mosquitoes thrive. Similarly, avian flu and salmonella often affect waterfowl, which are closely associated with wetlands,” explains academy research fellow Thomas Lilley from the Finnish Museum of Natural History.
This groundbreaking study, based on over 700 research papers and nearly half a million observations, reinforces the idea that climate change significantly impacts the risk of infectious diseases. As climate change alters the distribution of both pathogens and their wildlife hosts, such as birds, it sets the stage for shifts in disease transmission patterns. Birds are already moving northward at a rate of over one kilometer per year.
“Climate change might lead to the emergence of thermophilic pathogens in northern Europe,” speculates senior curator Aleksi Lehikoinen from the Finnish Museum of Natural History.
The findings, published in the esteemed scientific journal Ecography, were made possible through funding from the Academy of Finland’s “Climate Change and Health” research program, involving researchers from the University of Helsinki and the University of Turku.
As we grapple with the consequences of climate change, understanding its impact on disease transmission is a crucial step in safeguarding both human and animal health.