Pima County has five reported cases of the intestinal infection cyclospora, according to the Arizona Department of Health Services.
People are also reading…
Nineteen people have gotten the infection across the state, but Arizona's number is not considered to be an outbreak, the Arizona Republic reports.
Arizona is among 34 states reporting cases.
Cyclospora illness, also known as cyclosporiasis, is a gastrointestinal disease caused by a parasite found in food or water that may be contaminated with feces, says the U.S. Centers for Disease Control and Prevention.
This stained image provided by the Centers for Disease Control and Prevention shows cyclospora cayetanensis in a stool sample.
Symptoms include gas, cramping, bloating and "explosive" or watery diarrhea. After the parasite is ingested, symptoms can develop within two days or as late as two weeks.
Cyclosporiasis is often linked to raw fruits and vegetables. Some health officials in various states with more severe outbreaks, such as Michigan, say the most recent surge in cases is potentially caused by lettuce or salad greens.
Proper food handling is important to reduce the risk of getting infected, the CDC says. Wash all fruits and vegetables with running water, even prewashed, and scrub firm fruits and vegetables with a clean produce brush. It is also recommended to cut away any damaged or bruised areas on fruits and vegetables before eating.
The confirmed Arizona cases also include eight in Maricopa County, three in Yuma County and three in Pinal County.
The illness is not common, but seasonal cases routinely occur in Arizona, mostly in the summer months, the Arizona Republic reports. A total of 50 cases were reported in the state in 2025, state data show.
The Arizona number is significantly lower than case counts in Michigan, where reports of illnesses on July 14 reached 3,309.
Also, Arizona is not one of the four states where investigators believe current cyclosporiasis cases have an epidemiological link, the Republic says. Those states are Michigan, Ohio, West Virginia and Kentucky.
Q&A about the outbreaks
In a University of Arizona news release Thursday, a UA expert provided answers to common questions about the parasite.
The answers are from Gerardo "Jerry" Lopez, an associate professor and extension specialist in STEM, food safety and environmental microbiology in the UA School of Animal and Comparative Biomedical Sciences, who has spent years tracking how the parasite gets into agricultural water and onto fresh produce. He also sits on the U.S. Food and Drug Administration's cyclospora task force.
Why is cyclosporiasis making so many people sick right now?
A: People are getting sick from eating fresh produce, most likely, or berries that have been contaminated with human feces. That's where cyclospora is found. The produce could be imported or grown here in the U.S., and we often don't know how it became contaminated. It might be the irrigation water. It might be something in the handling, anywhere from the field to the processing plant to transportation to grocery stores or restaurants. Our fresh produce system is really a web, a network, going out to grocery stores, restaurants and schools. The produce industry and other stakeholders do the best they can to prevent these outbreaks. But once the parasite is on produce, it's hard to get off.
What makes an outbreak like this so hard to trace back to a source?
A: It's a complicated process. It can take two to 14 days for someone to start showing symptoms: the diarrhea, the nausea, the fatigue. So, by the time people are sick, investigators have to work backward and figure out what someone ate and where, whether it was at a restaurant or what they purchased at a grocery store. Then they must trace that product back to its source, determine if there are packages or produce left and test it for cyclospora. From historical data, we know these outbreaks tend to involve leafy greens and berries. But we don't yet know which product is responsible, or whether it's more than one, or whether it was imported or grown domestically. The CDC and FDA are hard at work on the traceback.
Is this year's outbreak actually worse, or are we just better at detecting it?
A: We don't know yet. The testing we're doing now is pretty much the same testing we've had the last couple of years, so it isn't that we suddenly got better at detecting it. Why there's been such an early uptick this year, and why in certain regions, we're not sure. One thing we're looking at is the heat. Cyclospora is temperature-dependent. It needs warmth to mature, so with the heat exposure this year, we're asking whether that happened sooner. Those are the questions our cyclospora task force is going to work on with the FDA, the CDC, other university experts and fresh produce industry stakeholders.
What's the best way for people to protect themselves?
A: The parasite isn't very susceptible to household chemicals, so it comes down to careful handling. Washing is the best tool we have, but you have to do it right. Rinse produce cleanly, and don't let the water coming off one item run down onto the rest. Wash one piece at a time, set it aside, and rub it as much as the product allows. Don't use soap or detergent. There are good resources out there on how to rinse vegetables properly. Watch for cross-contamination on your counters, too. Remember to use good hand hygiene practices by washing your hands before and after meal preparations. And while the outbreak is going on, it's reasonable to be a little cautious about what you order at restaurants. A lot of them are already taking steps to lower the risk. The good news is people generally don't die from this. There have been hospitalizations, but the main thing is to stay hydrated, and if it lasts more than a couple of days, see a doctor or go to urgent care.
What do people most often get wrong about cyclospora?
A: The biggest one is that people think it's bacteria. Bacteria like salmonella, listeria, E. coli and campylobacter multiply, even in your refrigerator, which is what makes them so dangerous. Cyclospora doesn't work that way. It can't multiply on your lettuce. If it's there, it's already there. It only becomes infectious after an infected person sheds it in their stool and it sits in the environment for a while, about two weeks, and that depends on temperature. Cyclosporiasis isn't a simple fecal-to-mouth infection, cyclospora has to mature in the environment first. That sets it apart from other parasites like cryptosporidium and giardia, which are infectious right away.
