The US Food and Drug Administration has reported additional illnesses in a separate Cyclospora outbreak that has not been linked to the ongoing lettuce-related outbreak. The development matters because it suggests health officials are dealing with more than one source of infection and have not yet identified the food responsible for the newer cluster.

Cyclospora is a parasite that can cause prolonged diarrhoea and other gastrointestinal symptoms. The FDA has begun traceback work on the unexplained outbreak, while continuing its separate investigation into illnesses associated with shredded iceberg lettuce; the two investigations should not be treated as the same outbreak.