The Centers for Disease Control and Prevention is working with state and local health officials to determine the source of a food-borne parasitic illness as cases rise in several states.

In its latest update Wednesday, the CDC said it received reports of 145 U.S.-acquired cases of cyclosporiasis in 17 states involving people who became sick from May 1 through June 16.

Cyclosporiasis causes explosive, watery diarrhea. The illness is typically not life-threatening and can be treated with antibiotics.

The CDC said at least 20 people have been hospitalized, and no deaths have been reported.

Separately, Michigan health officials are investigating an unusually large and growing outbreak. As of Friday, more than 170 cases were reported between June 22 and July 1, according to the state’s health department.

The state said it typically identifies only about 50 cases of cyclosporiasis a year.

"Based on the unusual number of cases we have identified in a little over a week, we anticipate additional cases of illness being reported," Dr. Natasha Bagdasarian, chief medical executive of the Michigan Department of Health and Human Services, said Wednesday in a news release. "We recommend Michiganders contact their healthcare provider if they experience sudden, ongoing diarrhea and reach out to their local health department if additional members of their family are suffering from the same symptoms."

There have been 112 confirmed cases in New York state, excluding New York City, since Jan. 1, the Rochester Democrat and Chronicle reported Friday, citing preliminary data from the state health department. Of those, 107 cases were reported since May 1.

Health officials in New York City said there were about twice as many cases reported from January through June of this year as during the same period last year, The New York Times reported Thursday.

The CDC said there was no immediate evidence of a single, multistate outbreak linking all of the cases. Investigators were working to identify potential clusters and sources of illness in multiple states.

Cyclosporiasis is caused by several species of the microscopic parasite Cyclospora cayetanensis, according to the CDC. The parasite spreads through raw produce and water contaminated with human feces. Symptoms include cramps, nausea, fatigue, loss of appetite, low-grade fever, and vomiting.

The most commonly reported symptom is "watery diarrhea with frequent and sometimes explosive bowel movements," according to the CDC.

The CDC recommends washing hands before and after handling produce, thoroughly rinsing fruits and vegetables under running water, scrubbing firm produce such as melons and cucumbers, cutting away damaged areas, and promptly refrigerating cut produce.

The CDC added that fruits and vegetables labeled "prewashed" do not need to be washed again at home.

Most people will recover from cyclosporiasis without needing treatment. Cases typically rise between May 1 and Aug. 31 annually, according to the CDC.