<\/p>\n <\/a><\/p>\n For one, warmer temperatures help speed up the maturation process that makes cyclospora oocysts, or early stage parasites, infectious to humans. That\u2019s why you typically see more cases of the infection during the summer months<\/a>. As climate change makes summers hotter<\/a> \u2014 and longer<\/a> \u2014 the window of time when cyclospora could become infectious and present a public health risk is also growing. <\/p>\n 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\u2019s 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. <\/p>\n I wish. 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<\/a>, Arizona, where a majority of the country\u2019s lettuce<\/a> 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.\u00a0\u00a0<\/p>\n Holly Bainbridge, a senior attorney at FarmSTAND, a legal advocacy organization, noted that studies like the USDA\u2019s point to a gap in the nation\u2019s regulatory oversight of the food system. \u201cIt was a step in the right direction, but the federal government hasn\u2019t really done anything with it,\u201d she said. <\/p>\n Bainbridge added that the corporate consolidation of agriculture \u2014 and specifically, the intensive confinement of animals on farms<\/a> \u2014 makes outbreaks of salmonella and E. coli more likely. <\/p>\n Last week, the FDA issued a recall<\/a> of over one and a half million eggs that have been potentially contaminated with salmonella. As of this writing, 98 people across 17 states<\/a> have been made sick, according to the latest numbers from the CDC.<\/p>\n This story was originally published by Grist<\/a> with the headline 4 things to know about cyclospora and climate change\u00a0<\/a> on Jul 30, 2026.<\/p>\n![\"17](\"https:\/\/grist.org\/wp-content\/uploads\/2026\/02\/toilet-water-flush.jpg\")
\n <\/figure>\nHow might climate change increase the risk of an outbreak?<\/h3>\n
Is cyclospora the only foodborne pathogen to worry about?<\/h3>\n
At the time, the outbreak had been contained to five states in the Midwest, according to the Centers for Disease Control and Prevention. Since then, the CDC has linked four more states<\/a> reporting cases of cyclosporiasis to contaminated lettuce from Taylor Farms, bringing the total of impacted states to nine. The CDC also stated that the outbreak has caused close to 2,000 cases of the illness \u2014 although that is likely an undercount<\/a>. (The CDC is also monitoring cases of cyclosporiasis that appear unrelated to this outbreak.)<\/p>\n There are a number of reasons why it can be difficult to track cases of cyclosporiasis. For example, many people may experience and manage symptoms, which include persistent, watery diarrhea, at home without ever seeing a doctor. <\/p>\n But the uneven rollout of information from public health authorities during this outbreak has further complicated matters. Former<\/a> federal food-safety officials<\/a> have criticized the Trump administration\u2019s handling of what is now considered the largest known cyclosporiasis outbreak in U.S. history<\/a>. <\/p>\n Unsaid in all of this is whether climate change and its impact on our globalized food system made this year\u2019s outbreak more likely. The answer is complicated. <\/p>\n \u201cThere are a couple things that make it a little difficult to fully assess what [the role of] climate change or changes in weather patterns could be,\u201d said Jeffrey Griffiths, a professor of public health at the Tufts University School of Medicine. \u201cBut I would say there’s still enough information that we have such that we can make some pretty reasonable inferences about how climate change would work.\u201d<\/p>\n Unlike other foodborne pathogens \u2014 like salmonella and E. coli, which exist in and on animals \u2014 cyclospora is transmitted through food or water that has been contaminated with human feces. When infectious, cyclospora causes explosive diarrhea and other gastrointestinal symptoms in humans. <\/p>\n Cyclospora can often linger in difficult-to-wash produce with uneven surfaces, like leafy greens and berries. Previous outbreaks have been tied to fresh produce including cilantro<\/a>, basil<\/a>, raspberries<\/a>, and other berries<\/a>. Thankfully, for anyone feeling overly cautious, cooking fresh produce kills this parasite. <\/p>\n Whether or not a person who has ingested the parasite becomes ill depends on the maturity level of the parasite at the time of exposure. Cyclospora is not immediately infectious when released in human stool. The parasite must undergo a maturation process that typically takes about one to two weeks. If cyclospora is ingested after that point, then it is considered infectious and causes gastrointestinal distress in its host. However, if the parasite is ingested before it has had enough time to mature, then it will likely pass without causing any illness. <\/p>\n This window of time wherein cyclospora is in the natural environment (say, in our water supply or on our produce) but not infectious to humans has created a lag in public health authorities\u2019 ability to trace the origins of the outbreak. <\/p>\n The exact origin of this specific outbreak is still unclear. Taylor Farms said in a statement that the company has voluntarily recalled its iceberg lettuce products that came from central Mexico \u201cout of an abundance of caution\u201d and has also reached out to \u201cindependent experts\u201d to review its food-safety protocols.<\/p>\n But experts say there are a few potential pathways for contamination \u2014 most having to do with how water is used and managed for agricultural production. <\/p>\n In many past outbreaks of cyclospora that have been associated with fresh produce, \u201cwe\u2019ve seen that water is critical,\u201d said Kalmia Kniel, a professor of microbial food safety at the University of Delaware. If the irrigation water supply on an agricultural site comes into contact with wastewater, for example, and is not adequately filtered, then it runs the risk of contaminating crops meant for human consumption. <\/p>\n \u201cThere’s lots of different little mechanisms where that could happen,\u201d said Griffiths \u2014 like if agricultural fields are located adjacent to faulty sanitation systems. In these cases, storm events resulting in flooding or water runoff could lead to cross-contamination. Additionally, if a farm reuses municipal wastewater as part of its irrigation system and that wastewater is not treated to a high enough standard so as to remove pathogens, it poses a risk of transmitting cyclospora to crops. <\/p>\nFirst off, what is cyclospora?<\/h3>\n
How does human fecal matter enter our food or water supply to begin with?<\/h3>\n