WASHINGTON — U.S. health authorities are continuing to investigate a growing outbreak of Cyclospora infections, a parasitic intestinal illness associated with contaminated food.

The CDC, FDA and state and local health departments have expanded the investigation to 20 states after identifying additional cases. Authorities have linked the outbreak to iceberg lettuce served at Taco Bell restaurants, with the lettuce traced to Taylor Farms operations in central Mexico.

The outbreak has resulted in 11,458 reported cases and 495 hospitalizations in the latest Reuters report, although health authorities continue updating the figures as additional infections are identified.

Cyclospora is a parasite that can cause prolonged gastrointestinal symptoms, making food-safety investigations particularly important when contaminated produce is distributed across multiple states.

Health officials are continuing to investigate the supply chain and distribution of the affected lettuce while monitoring new cases.

The expanding investigation highlights the challenges of tracing contaminated fresh produce across state and international supply chains.

The outbreak also comes as U.S. consumers and retailers face increasing scrutiny over foodborne illnesses involving fresh produce. Federal agencies are working with state health departments to identify additional cases and determine whether further food products or locations could be involved.