Michigan health officials have lifted their warning against bagged lettuce and pre-packaged salad mixes after reported cyclosporiasis cases began to decline. The move signals that the immediate risk appears to have eased, although the wider investigation into the parasite outbreak and its food sources continues.

The outbreak was linked in part to shredded iceberg lettuce sourced from central Mexico and served at some Taco Bell restaurants, prompting a July recall. Michigan had recorded more than 11,000 cases, 193 hospitalisations and two deaths among people with significant underlying health conditions; the state normally reports about 40 to 50 cases a year.