Weather conditions associated with climate change are exacerbated by the spread of foodborne pathogens Salmonella and Campylobacter, according to recent studies from researchers at the University of Surrey’s School of Veterinary Medicine. Led by Gianni Lo Iacono, Ph.D., this research sheds light on the alarming connection between changing climates and increasing foodborne illness cases.
Salmonella infections are responsible for nearly one-third of foodborne illnesses across Europe. A study recently published in the Journal of Infection utilized novel statistical models to estimate the incidence of salmonellosis based on fourteen different weather factors. This research analyzed data provided by the UK Health Security Agency (UKHSA) concerning confirmed Salmonella infections in England and Wales between 2000 and 2016, compared with weather data from the UK Met Office.
Through this study, researchers pinpointed significant weather factors contributing to the rise of Salmonella infection rates. These factors include: warmer temperatures above 10 °C, relative humidity with dewpoints ranging from 7 to 10 °C, and longer day lengths between 12 and 15 hours. Conversely, other weather variables—such as air pressure, wind speed, temperature amplitude, and the duration of sunshine—showed limited or no correlation with salmonellosis incidences. The model’s application beyond the UK, particularly its promising adaptation to the Netherlands, demonstrates its potential utility for predicting incidence trends.
Building on previous findings about climatological impacts, another study from the University of Surrey examined the prevalence of campylobacteriosis, another significant foodborne illness. The research, published previously in PLOS Computational Biology, suggests climate change could also worsen the outbreak of Campylobacter infections, which are the leading cause of human bacterial gastroenteritis worldwide, as reported by the World Health Organization (WHO).
Researchers analyzed data pertaining to approximately one million confirmed campylobacteriosis cases collected by UKHSA over two decades, cross-referencing it with weather information from the UK Met Office. Their findings revealed consistent campylobacteriosis rates at temperatures below 8 °C. Notably, there was around one additional case per million for every 5-degree rise above the said threshold. The incidence of this infection dramatically increased as humidity levels approached 75 to 80 percent and exceeded ten hours of daylight. Meanwhile, rainfall and wind conditions appeared less influential on the spread of Campylobacter.
According to Dr. Lo Iacono, "Warmer temperatures above 10 °C, relative humidity of dewpoint 7–10 °C, and day lengths of 12–15 hours contribute to increased Salmonella infections." This compelling insight supports the pressing need for public health strategies to combat rising infection rates attributed to climate change.
The World Health Organization has highlighted, "Campylobacter infections are the most common cause of human bacterial gastroenteritis worldwide," underscoring the importance of recognizing climate impacts on pathogens. The interrelation between climate and health becomes even clearer as global temperatures rise and extreme weather events become more frequent, bringing with them significant health challenges.
These studies collectively suggest not only the immediacy of addressing climate change but also the necessity for improved monitoring of foodborne illnesses linked to climatic factors. Understanding and forecasting infection rates based on weather patterns could enable health authorities to allocate resources more effectively, implement preventive measures, and educate the public on food safety practices as climate conditions fluctuate.
With increased awareness and greater public discourse on the impacts of climate change—especially on food safety—society can work collaboratively toward solutions. The evidence linking climate factors and the rise of foodborne pathogens like Salmonella and Campylobacter exemplifies the urgent need for actionable measures to safeguard public health.