Michigan health officials said Thursday that residents could return to their usual salad routine as cyclosporiasis cases in the state continue to fall.

Michigan has logged the most cases of the parasitic infection, which causes explosive diarrhea, as the illness has surged across the U.S. Michigan has reported 12,485 cases of cyclosporiasis since June, including 279 hospitalizations and two deaths.

Case reports, however, are slowing, officials said, “including a downward trend in diarrhea-related emergency department visits.”

On Thursday, Michigan’s health department said that the majority of people sickened were exposed in late June to early July, and that “the majority of contaminated produce is likely no longer available for consumption.”

Michigan residents no longer need to avoid bagged salads, the health department said Thursday, and could also return to their usual produce-handling practices.

Residents should still avoid recalled lettuce, it added.

Fifteen states have been connected to the cyclosporiasis outbreak, the Centers for Disease Control and Prevention said Wednesday, which has been linked to shredded iceberg lettuce served at Taco Bell restaurants and supplied by Taylor Farms de Mexico.

The Food and Drug Administration announced that on July 17 Taylor Farms voluntary recalled all of its iceberg lettuce grown in central Mexico. That lettuce had been distributed to restaurants and retailers in 27 states. Retailers included selected Walmart locations, which sold the lettuce under the Marketside brand.

In addition to avoiding the recalled lettuce, Michigan health officials recommended that people purchase whole heads of lettuce or salad greens instead of bagged salads, discard the outer layers and thoroughly wash the remaining inner leaves before eating.

On Wednesday, the CDC said that four people in Michigan had been sickened in an unrelated outbreak of salmonella linked to jalapeños.