Health officials across the United States are investigating a major rise in illnesses caused by Cyclospora, a microscopic parasite that can lead to a prolonged intestinal infection.
The investigation has expanded as thousands of people have reported symptoms in different parts of the country. Federal agencies and state health departments are working to determine which illnesses are connected to the same source and how widely the outbreak has spread.
One of the largest identified clusters has been associated with shredded iceberg lettuce served at Taco Bell restaurants in several states. Investigators have linked the lettuce to a supplier that sourced the produce from central Mexico. The affected lettuce was subsequently recalled as officials worked to prevent additional illnesses.
The Cyclospora outbreak is part of a broader increase in cyclosporiasis cases reported nationwide this summer. Federal surveillance data shows that thousands of laboratory-confirmed domestic cases have been reported since May, although officials say the actual number of infections may be considerably higher because some cases remain under investigation.
How the Outbreak Was Traced
Investigators began looking for common connections among people who became sick after eating at different locations.
The investigation eventually identified a pattern involving shredded iceberg lettuce. Health authorities determined that illnesses in several states were associated with lettuce served at Taco Bell locations, prompting federal agencies to investigate the supply chain.
By late July, the identified outbreak had expanded to nine states, including Illinois, Indiana, Kansas, Kentucky, Michigan, Ohio, Oklahoma, Pennsylvania and West Virginia. At that stage, nearly 2,000 illnesses had been associated with the specific outbreak, along with dozens of hospitalizations.
However, officials have stressed that not every Cyclospora infection reported across the country is necessarily connected to this particular outbreak. Other cases and potential clusters are being investigated separately.
The FDA and CDC have been working with state and local health departments to identify additional links and determine whether other foods or sources could be involved.
What Is Cyclospora?
Cyclospora is a parasite that causes an intestinal illness known as cyclosporiasis. People can become infected by consuming food or water contaminated with the parasite.
Symptoms commonly include frequent watery diarrhea, stomach cramps, nausea, loss of appetite and fatigue. Some people can experience symptoms for an extended period if the infection is not treated.
The parasite has historically been associated with fresh produce, particularly leafy greens and certain fruits and herbs. Contamination can occur when produce comes into contact with contaminated water or other sources during growing, harvesting, processing or handling.
Health authorities say the infection is different from many common foodborne illnesses because symptoms can persist or return over time.
Officials Continue Tracking New Cases
The Cyclospora outbreak investigation remains complicated because cases can take time to identify and report.
Health departments must determine whether an illness was acquired domestically, associated with international travel or connected to a particular food source. Some reported cases also require additional testing or investigation before they can be classified as part of a specific outbreak.
Federal surveillance data indicates that the number of reported cases has continued to grow, with infections recorded in numerous states. Authorities caution that surveillance totals can change as laboratories and health departments process additional reports.
Officials are also investigating other potential Cyclospora clusters that do not appear to be connected to the lettuce-associated outbreak.
Consumers Urged to Follow Food Safety Practices
While investigations continue, health officials continue to encourage consumers to follow basic food safety measures when handling fresh produce.
People should wash produce thoroughly under running water, keep food preparation surfaces clean and avoid cross-contamination between raw foods and ready-to-eat items.
Anyone experiencing persistent diarrhea or other concerning gastrointestinal symptoms should contact a healthcare professional, particularly if symptoms continue for several days or lead to dehydration.
The Cyclospora outbreak has also renewed attention on the challenges involved in tracking foodborne illnesses through complex supply chains. A contaminated ingredient can move through multiple states before health officials identify a common connection.
For now, investigators are continuing to analyze case reports, trace food distribution networks and examine possible sources. As additional information becomes available, health authorities may be able to determine the full scale of the outbreak and whether other products are involved.
