Michigan officials say lettuce and salad greens may be linked to parasite outbreak

Michigan health officials said on Monday that lettuce and other salad greens are a possible source of a cyclosporiasis outbreak that has sickened thousands of people. The state health department said the inquiry is still under way and that other food sources have not been ruled out.

Cyclosporiasis is a parasitic infection that can cause watery diarrhea, loss of appetite and weight loss. Officials said the early evidence points to leafy produce, but they have not yet identified a single confirmed source.

The announcement came as public health investigators continued tracing the outbreak and reviewing food exposures reported by patients. The department said the findings remain preliminary.

Cyclosporiasis outbreaks are typically investigated through interviews, food histories and supply-chain checks, and officials said more work is needed before the source can be confirmed.