Climate change is altering the spread of waterborne diseases around the world, according to a comprehensive review published today in Nature Reviews Microbiology . The publication is the most up-to-date and comprehensive analysis to date examining how climate change influences waterborne diseases.
The review warns that more frequent extreme weather events could undermine decades of progress in reducing waterborne diseases, which contribute to nearly 1.2 million deaths from infectious diarrhea each year.
Led by researchers from the Colorado School of Public Health at the University of Colorado Anschutz and the University of Washington School of Public Health, the review found that climate change does not affect all disease-causing microorganisms, known as pathogens, in the same way.
Instead, bacteria, viruses and parasites each respond differently to changing environmental conditions, showing why managing the public health response should be tailored to specific pathogens.
“We want people to know climate change changes the conditions that allow pathogens to spread,” said the review’s co-author Elizabeth Carlton, PhD, professor and chair of the Department of Environmental and Occupational Health at the Colorado School of Public Health. “It’s making it harder to control some of the world’s most deadly infectious diseases by creating more favorable conditions for transmission.”
Climate change affects transmission in multiple ways
The review explains that climate change alters the environmental conditions that determine whether pathogens survive, spread and infect new hosts. For example, while waterborne diseases are often associated with flooding and heavy rainfall that carry pathogens into drinking water supplies, the authors explain droughts can also increase disease risk by reducing access to safe water and changing how people use the water that is available.
The review also explains that rising temperatures generally promote bacterial growth, while some viruses, including norovirus, rotavirus and adenovirus, spread more easily under cooler, drier conditions - and may, in fact, decrease in a warmer world.
Public Health strategies that can reduce risk
The review outlines practical steps that can help communities adapt to the growing threat of climate-driven waterborne diseases.
These strategies are described in the paper as “no-regrets” investments because they not only reduce waterborne disease today but also help communities become more resilient to the health impacts of climate change.
“Climate change is changing the rules of how these diseases spread,” Carlton said. “The good news is we already have many of the tools needed to reduce risk. The challenge now is making sure they're designed and deployed for the climate conditions we're facing today and the ones we'll face in the future.”
The authors conclude that no single strategy will protect against every waterborne disease. Instead, they say climate adaptation efforts should account for how individual pathogens respond to changing environmental conditions, allowing public health officials to better anticipate and prevent future outbreaks.
About the University of Colorado Anschutz
The University of Colorado Anschutz is a world-class academic medical campus leading transformative advances in science, medicine, education and patient care. The campus includes the University of Colorado’s health professional schools, more than 60 centers and institutes, and two nationally ranked independent hospitals - UCHealth University of Colorado Hospital and Children's Hospital Colorado - which see nearly three million adult and pediatric patient visits each year. Innovative, interconnected and highly collaborative, CU Anschutz delivers life-changing treatments, exceptional patient care and top-tier professional training. The campus conducts world-renowned research supported by $890 million in funding, including $762 million in sponsored awards and $128 million in philanthropic gifts for research.
Nature Reviews Microbiology
Waterborne diseases and climate change