Cyclosporiasis Cases Continue to Surge Nationwide

Cyclosporiasis cases in Michigan continue to rise, with 3,309 reported as of July 13, according to the Michigan Department of Health and Human Services (MDHHS).

Of these cases, 44 have been hospitalized as of July 9, said MDHHS. No deaths have been reported. Cases began being reported on June 22.

While the investigation is ongoing, available information indicates that lettuce or salad greens may be a potential source of the outbreak, said MDHHS. However, other food items cannot be ruled out, and no specific type of produce, grower or supplier has been identified as the source, the agency said.

The U.S. Centers for Disease Control and Prevention (CDC) is investigating cyclosporiasis outbreaks nationally. Its latest count accounts for 1,645 cases across 34 states, with 141 hospitalized.

CDC said it assumes a 6-week reporting lag between illness onset and case reporting to CDC. The agency said it is aware that states are likely to report higher case counts of cyclosporiasis than reflected in CDC data and added that it is working closely with states to update numbers as additional cases are confirmed.

Other states have reported their own cases of cyclosporiasis, including Ohio, which has reported 364 cases as of July 9, and New York, which has reported 470 cases since May 1.

Of the 1,645 cases reported by CDC, sick people ranged in age from 2 to 95, with a median age of 44, and 56% were female. The median illness onset date was June 22 (range from May 1 to July 9). 

Local, state, and federal (CDC, FDA) public health authorities are investigating several clusters of cases in more than one state. Investigations to identify potential sources are ongoing.

Cyclosporiasis cases may not be limited to states with known cases, CDC said. The true number of people sick with cyclosporiasis is likely higher than the number reported, the agency added.

Cases Acquired Outside the U.S.

As of July 13, CDC is reporting an additional 440 cases of cyclosporiasis in people who ate or drank food or water that made them sick while they were traveling outside the United States during the 14 days before they got sick.

These cases were reported by 35 states. Sick people ranged in age from 14 to 89, with a median age of 45, and 59% were female. The median illness onset date was June 9 (range from May 1 to July 8).

Of the 440 people with information available, 20 were hospitalized. No deaths have been reported.

What Is Cyclosporiasis?

Cyclosporiasis is an intestinal illness caused by the Cyclospora parasite. People can become infected by consuming food or water that contains the parasite.

Cyclospora infects the small intestine (bowel) and usually causes frequent, watery and explosive diarrhea. The time between being exposed and becoming sick is usually about one week but can range from two days to two weeks or more. Untreated, the illness may last from a few days to more than a month. Symptoms may go away and then return.

Cyclosporiasis is not usually life-threatening, but dehydration from frequent bouts of diarrhea can cause severe illness, particularly among younger or older people and those who have weakened immune systems.