By IDSE News Staff
Temperature, day length and humidity have been linked to the increased spread of a diarrheal illness. The findings could help predict further outbreaks of the illness, potentially leading to better preparedness within health services (PLoS Comput Biol 2024;20[1]:e1011714).
Researchers led by Giovanni Lo Iacono, PhD, investigated the impact of weather on the transmission of Campylobacter, the most common cause of human bacterial gastroenteritis in the world. Infections are generally mild, but can be fatal among very young children, older adults and immunosuppressed individuals.
“Since Hippocrates, there has been a large consensus that weather and climate influence the spread of diseases. Getting to the bottom of why this is and what specific environmental factors drive the spread of disease is a complicated matter and not fully understood. We now have a detailed description of how the weather affects the disease, and the next step is to understand the why. Importantly, through our transparent and conceptually simple approach, we can now tell the risk of getting the disease when we know the recent local weather,” said Dr. Lo Iacono, a senior lecturer in biostatistics and epidemiology in the School of Veterinary Medicine at the University of Surrey, in England, and who contributed to the recent UK Health Security Agency’s (UKHSA’s) Health Effects of Climate Change report.
To determine how weather affects the incidence of campylobacteriosis, researchers analyzed data from approximately 1 million cases of campylobacteriosis in England and Wales over a 20-year period from UKHSA. An innovative mathematical model was developed by the team enabling them to compare these data provided by the Met Office with weather parameters at the time. The analysis showed incidence of campylobacteriosis was consistent below temperatures of 8° C.
However, a sharp increase in infection (approximately one case per 1 million) were observed for every 5-degree rise in temperature, where temperatures were between 8° C and 15° C.
A link to humidity was identified by the team, which also observed a high incidence of infection when levels of water vapor in the air were between 75% and 80%.
Of note, the researchers also observed strong associations between day length (longer than 10 hours) and increased cases of the illness. This association was further strengthened when humidity was also high.
However, rainfall and wind speed were not strongly linked to the spread of campylobacteriosis.
“What we have found is that rising temperatures, humidity and increased day length are associated with the spread of campylobacteriosis. We do not fully understand why this may be. It could be that warm weather increases the survival and spread of pathogenic bacteria, so the weather causes the disease, or alternatively it could be people’s behavior and how they socialize during such periods.
“However, what we do know is climate change not only has an environmental impact but has the potential to negatively affect our health by aiding the spread of infectious diseases.”
