WASHINGTON, DC — A fast-moving cyclosporiasis outbreak has sickened thousands of people across the country, and health officials say the count is still climbing. The illness is tied to a microscopic parasite that can cause frequent, watery diarrhea, sometimes described as explosive, and it has already been linked to hospitalizations and deaths in Michigan.
Here is a plain-English look at what the CDC and state health agencies say so far, including where cases are concentrated, what may be driving the outbreak, and how people can lower their risk.
1. The outbreak has spread to 45 states
By late July, the CDC said 45 states had reported cyclosporiasis cases. From May 1 through July 27, the agency confirmed 6,707 cases nationwide, along with 423 hospitalizations. Officials also said they were aware of more than 11,500 additional illnesses that had not yet been lab confirmed or fully reviewed.
The numbers are expected to rise as new reports come in. Health experts also warn the real total is probably higher because some people recover without ever being tested or seeking medical care.
2. Michigan has been hit especially hard
Michigan is among the hardest-hit states, and state officials reported two deaths on Aug. 3. Health authorities said both people had significant underlying health conditions that may have been affected by cyclosporiasis and dehydration.
The outbreak has also been severe in Ohio, while Illinois, New York and North Carolina have each reported hundreds of cases. Even with those tallies, the CDC says the situation remains fluid and the case count could keep changing quickly.
3. Cyclosporiasis is a parasitic intestinal illness
Cyclosporiasis is caused by a microscopic parasite called cyclospora. People usually get infected by eating contaminated food or drinking contaminated water. The CDC says the illness is less common than foodborne infections such as salmonella or E. coli, and it is not usually life-threatening.
Symptoms do not always show up right away. When they do, they often include diarrhea with frequent and sometimes explosive bowel movements, and it usually takes about a week after exposure to become sick.
4. Symptoms can linger or come back
For some patients, cyclosporiasis passes in a few days. For others, it can last more than a month if left untreated. The CDC says symptoms can also fade and then return, which can make the illness confusing to track.
Not everyone infected gets sick, but those who do may feel enough gastrointestinal distress to need medical attention. Because dehydration can become a concern, public health officials urge people with ongoing diarrhea to check in with a health provider.
5. One lettuce-linked cluster spans nine states
The CDC says one multi-state cluster has been tied to iceberg lettuce and has affected nine states. In response, Taylor Farms recalled all iceberg lettuce sourced from central Mexico. Officials say the people linked to that cluster became ill after eating food in the United States and had not traveled abroad in the two weeks before getting sick.
Other cyclosporiasis outbreaks in the U.S. have been linked to bagged salad mixes, cilantro, basil, raspberries, snow peas and green onions. The CDC says some of the current outbreaks may be unrelated to the lettuce cluster.
6. Person-to-person spread is not how this illness moves
Experts say cyclosporiasis does not spread from one person directly to another. Dr. Caitlin Rivers of the Johns Hopkins Center for Health Security wrote in an July 8 newsletter that transmission is fecal-oral, meaning it happens when someone ingests contaminated food or water.
That matters for prevention because it means kitchens, farms and food handling practices are central to controlling risk. The CDC says the outbreak cases it is tracking came from people who ate food in the U.S., not from recent foreign travel.
7. Washing produce helps, but recall advice matters most
Michigan health officials recommend extra caution in restaurants and kitchens that serve raw produce. Their advice includes thoroughly washing greens, cooking raspberries and leafy greens when possible, and removing outer layers of lettuce and green onions to cut risk.
For the recalled iceberg lettuce tied to the outbreak, the CDC is more direct: do not eat it. If you bought recalled lettuce from Taylor Farms de Mexico, health officials say to throw it away or return it. The FDA says rinsing produce is unlikely to be effective, even though the CDC still recommends rinsing as part of safer food handling.
What this means for consumers
The outbreak is a reminder that foodborne illness can spread widely before the source is pinned down. For now, the most important steps are to follow recall notices, watch for symptoms after eating raw produce, and seek medical advice if diarrhea develops.
With case numbers still moving upward, public health agencies say the investigation is ongoing and more updates are likely.
