How Might Climate Change Increase the Risk of an Outbreak?

For one, warmer temperatures help speed up the maturation process that makes cyclospora oocysts, or early stage parasites, infectious to humans. That’s why you typically see more cases of the infection during the summer months. As climate change makes summers hotter — and longer — the window of time when cyclospora could become infectious and present a public health risk is also growing.

Another way that climate change supercharges the conditions for an outbreak like cyclosporiasis is by disrupting the water cycle. Extreme heat sucks moisture out of the environment, from rivers and lakes as well as the soil and plants. During drought conditions, agricultural producers are more likely to reuse nontraditional water sources, such as municipal and commercial wastewater, to irrigate crops. What’s more, cycling between drought and downpours means that when it does rain on dry soil, more runoff carries more particles and organisms across a landscape.

there’s even more pathogens to worry about too:

Food system researchers have seen how very dry, hot conditions supercharge the likelihood of other foodborne pathogens, such as salmonella and E. coli. In 2024, the U.S. Department of Agriculture released a multiyear study centered on Yuma County, Arizona, where a majority of the country’s lettuce is grown in the winter months. The researchers found that dust kicked up from a nearby cattle feedlot helped carry E. coli through the air and deposit the bacteria on nearby water and soil.

Holly Bainbridge, a senior attorney at FarmSTAND, a legal advocacy organization, noted that studies like the USDA’s point to a gap in the nation’s regulatory oversight of the food system. “It was a step in the right direction, but the federal government hasn’t really done anything with it,” she said.

Bainbridge added that the corporate consolidation of agriculture — and specifically, the intensive confinement of animals on farms — makes outbreaks of salmonella and E. coli more likely.

Last week, the FDA issued a recall of over one and a half million eggs that have been potentially contaminated with salmonella. As of this writing, 98 people across 17 states have been made sick, according to the latest numbers from the CDC.