Parasite Outbreak Lettuce U.S.
Health officials across the United States are investigating a widespread outbreak of cyclosporiasis, a foodborne illness caused by the microscopic parasite Cyclospora cayetanensis. The outbreak has affected more than 30 states, with health experts increasingly focusing on fresh lettuce as a possible source of the infections.
The Centers for Disease Control and Prevention (CDC), along with state health departments and the U.S. Food and Drug Administration (FDA), are working to identify where the contaminated produce originated. While investigators have not yet identified a specific farm, supplier, or brand, officials say lettuce has emerged as a common food reported by many people who became ill.
Investigation Points Toward Fresh Produce
Health officials in Michigan, which has reported one of the largest concentrations of cases, say interviews with patients suggest lettuce may be responsible for a significant portion of the illnesses. However, investigators caution that the investigation remains active and that other fresh produce could also be involved.
Cyclospora outbreaks have historically been linked to fruits and vegetables that are eaten raw because the parasite can survive on produce before it reaches consumers. Once contaminated food enters the distribution chain, illnesses can spread across multiple states within weeks.
Thousands of Cases Under Review
The CDC has confirmed more than 1,600 domestically acquired cases of cyclosporiasis this year, but officials believe the true number is much higher. Thousands of additional illnesses are still being investigated as laboratories continue testing patient samples from around the country.
Public health experts note that many people with mild symptoms never seek medical care, meaning official case counts likely underestimate the scope of the outbreak.
What Is Cyclospora?
Cyclospora cayetanensis is a microscopic parasite that infects the small intestine after contaminated food or water is consumed. Unlike bacteria that often cause food poisoning, Cyclospora requires time outside the human body before it becomes infectious, making direct person-to-person transmission uncommon.
Fresh produce, particularly leafy greens, herbs, berries, and vegetables that are eaten without cooking, has been linked to previous outbreaks because the parasite is difficult to eliminate once it contaminates crops.
Symptoms Can Last for Weeks
People infected with Cyclospora typically develop symptoms about one week after exposure, although illness can begin sooner or later. The infection commonly causes prolonged watery diarrhea, stomach cramps, nausea, vomiting, bloating, fatigue, loss of appetite, and weight loss.
Without treatment, symptoms can continue for several weeks and may disappear and return multiple times. Doctors typically prescribe antibiotics to treat the infection, and most patients recover fully after receiving appropriate care.
Older adults, young children, and people with weakened immune systems are considered to be at greater risk for severe illness.
Consumers Should Remain Cautious
Health officials are encouraging consumers to practice safe food handling while the investigation continues. Washing hands before preparing meals, rinsing fruits and vegetables, separating raw foods from ready-to-eat items, and seeking medical attention for prolonged diarrhea can help reduce the risk of illness.
Experts also note that washing produce alone may not completely remove Cyclospora because the parasite can cling tightly to the surface of leafy vegetables. Cooking contaminated produce is one of the most effective ways to destroy the parasite.
No Recall Issued Yet
At this time, federal officials have not announced a nationwide recall because investigators have not identified a single source responsible for the outbreak. The CDC and FDA continue tracing food distribution networks and interviewing patients in hopes of determining where the contamination occurred.
Until investigators identify the source, health officials expect additional cases may continue to be reported throughout the summer as laboratories process new test results and more people seek medical care.
