U.S. public health officials are investigating a nationwide cyclospora (cyclosporiasis) outbreak that has caused thousands of illnesses and outbreaks of watery, sometimes “explosive” diarrhea. Multiple outlets report that the suspect ingredient is iceberg lettuce used at Taco Bell, traced to a supplier connected to outbreaks in several states. Reports say cases have been reported across more than 30 states, with particular concentration in Michigan, and illness counts and hospitalizations vary by outlet, though several describe over 1,600 reported cases and dozens of hospitalizations in a smaller number of states. Investigators trace contaminated lettuce through the supply chain to a farm and supplier linked to the lettuce provided to Taco Bell. One supplier, Taylor Farms, is reported to have voluntarily removed iceberg lettuce from the U.S. market and initiated a recall. In response, Taco Bell says it removes potentially affected lettuce from some restaurants in states identified as part of the investigation and plans to replace the ingredient quickly. Officials also caution that not every illness may have come from a single source as the investigation continues.