A source familiar with the investigation told the outlet that some sickened people interviewed reported having eaten at Taco Bells, while others did not, suggesting that there could be multiple sources of the contaminated food item.

Identifying the source of Cyclospora can be difficult because it can take up to two weeks between when a person eats contaminated food and when they develop symptoms, making recall of the possible food sources difficult, the MDHHS noted. They also pointed to the “complex food distribution networks” as complicating factors in tracking the source or sources.

National situation

While Michigan is seeing the highest numbers of cases, at least 31 states are also reporting illnesses. New York has reported 470 cases. Ohio is seeing at least 397 cases. North Carolina has reported at least 240. (The Centers for Disease Control and Prevention is collecting data on the cases, but is reporting them slowly.) The nationwide tally is well over 4,000 already at this point in the summer, which is when cyclosporiasis cases peak. In past years, the US has typically reported between 2,000 and 5,000 cases a year.

Amid the outbreak with no clear source as of yet, health officials are recommending that people be cautious about leafy greens, particularly bagged or boxed greens. It’s recommended to instead buy whole heads of lettuce, discard the outer two or three layers of leaves, and then wash the rest thoroughly. But, sticking with peel-able or smooth-surfaced produce is safer. The safest choice is cooking produce to at least 158° F (70° C), which will kill the parasite.

Past cyclosporiasis outbreaks have been linked to bagged salad mixes and kits, fresh cilantro, fresh basil, raspberries, snow peas, and green onions, MDHHS notes.

People who experience frequent watery diarrhea should consult with their healthcare provider. An antimicrobial treatment can treat the infection, along with rest and hydration.