Outbreak Overview and Nationwide Impact
An outbreak of cyclosporiasis, an intestinal illness caused by the microscopic parasite *Cyclospora*, has spread across 31 states. As of mid-July, federal health authorities reported 843 confirmed cases of the infection, with 86 hospitalizations and no deaths. However, public health officials caution that the true number of infections is likely much higher. The Centers for Disease Control and Prevention (CDC) indicated it is aware of more than 1,500 additional cases requiring further analysis, and total figures are expected to rise due to an estimated six-week lag between the onset of illness and reporting to federal authorities.
While cases have been reported from California to Texas to Florida, the Midwest and Northeast appear to be among the hardest-hit areas. Michigan has reported a significant number of cases, with over 1,500 reported as of Friday. Other states have also seen substantial figures, including nearly 300 cases in New York, 177 in Ohio, and 141 in Illinois. Health officials noted that while infections typically rise during the spring and summer, multiple states have experienced a larger jump in cases over the recent two-week period compared to the same time last year.
Understanding the Illness and Symptoms
Cyclosporiasis is a gastrointestinal affliction transmitted through the consumption of contaminated food or water. According to the CDC, the illness is generally not fatal but is considered a serious condition that can cause dehydration, potentially requiring patients to seek emergency medical care.
Symptoms of the infection include nausea, fatigue, and diarrhea, which the CDC describes as potentially “explosive.” If left untreated, the illness may last from a few days to over a month, and symptoms have been known to return after appearing to dissipate. Those sickened in the current outbreak have ranged in age from 5 to 88 years old. Medical professionals typically treat the infection with antibiotics.
For more on this story, see Norton Healthcare Reports Cyclosporiasis Spike in Kentucky Amid National Outbreak.
Investigation Into the Source
Despite the widespread nature of the outbreak, health officials have not yet identified a specific source. Investigators are currently interviewing sickened individuals to determine what they consumed, though this process is complicated by the nature of the parasite. Symptoms can appear anywhere from two days to two weeks or more after infection, making it difficult for patients to accurately recall their dietary history.
Historically, outbreaks of cyclosporiasis in the United States have been associated with fresh produce, including raspberries, basil, cilantro, snow peas, and lettuce. In 2018, McDonald’s removed salads from restaurants in 14 states following a link to dozens of cases, and in 2013, tainted lettuce imported from Mexico was suspected of sickening 400 people. Regarding the current surge, major berry supplier Driscoll’s stated that health officials have not contacted the company regarding any connection to the rise in cases.
This follows our earlier report, Michigan Cyclosporiasis Cases Surge to Over 700 in Unusual Parasitic Outbreak.
Prevention and Food Safety Guidance
Public health officials have not recommended that the public stop eating fresh fruits and vegetables, noting that such produce is part of a healthy diet. Instead, they emphasize safe handling and preparation practices.
The CDC and state health departments offer the following guidance to reduce the risk of infection:
| Recommendation | Best Practice |
| :— | :— |
| Cooking | Heat produce to at least 158 degrees Fahrenheit to kill the parasite. |
| Washing | Rinse fruits and vegetables thoroughly under running water. |
| Handling | Wash hands with soap and water before and after handling produce. |
| Preparation | Remove outer leaves of lettuce and the outer layer/root of scallions. |
| Storage | Refrigerate cut or peeled produce within two hours. |
Experts advise against using dish soap to clean produce, as it may leave a residue that can cause stomach upset. While some state departments have suggested cooking items like raspberries and leafy greens when possible, officials note that the effectiveness of these measures is not medically proven. Consumers are encouraged to see a doctor if they experience severe diarrhea or signs of dehydration.
Read also: CDC Investigates Outbreak of ‘Explosive’ Diarrhea Across 18 States.
Find more reporting in our Health section.
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