Outbreak of Parasite Causes Severe Illness in 170 Michigan Residents

WHO:

NBC News - The U.S. Centers for Disease Control and Prevention (CDC) is involved in investigating the outbreak.

NBC News - Health officials from the Michigan Department of Health and Human Services (MDHHS) are investigating the outbreak.

WHAT:

ClickOnDetroit | WDIV Local 4 - Over 300 cases of cyclosporiasis have been reported within a week in Southeast Michigan.

ClickOnDetroit | WDIV Local 4 - The age range of individuals diagnosed with the illness ranges from 8 years old to 84 years old, with a median age of 41.

The Guardian - More than 400 cases of cyclosporiasis have been reported across 18 states.

NBC News - The CDC reported that as of July 1, there were at least 300 cases in Michigan, up from 170 just days prior.

The Guardian - More than 300 cases of cyclosporiasis have been reported in Michigan since June 22, 2026.

NBC News - Health officials in Michigan anticipate additional cases of illness being reported due to the unusual number of cases identified in a short period.

NBC 5 Chicago - The Michigan Department of Health and Human Services reported that the outbreak has impacted more than 170 individuals in just nine days.

NBC News - The Michigan Department of Health and Human Services reported that the outbreak has impacted more than 100 individuals in just nine days.

NBC News - The CDC noted that the true number of people sick with cyclosporiasis is likely higher than the number reported.

NBC News - As of July 1, Michigan health officials reported that more than 170 cases of cyclosporiasis were identified across seven counties.

NBC News - A county-by-county breakdown of cases in Michigan includes: Monroe (70), Lenawee (33), Washtenaw (21), Wayne (12), Jackson (7), Shiawassee (7), and 24 cases in 11 other counties and the City of Detroit.

NBC News - The number of reported cases of cyclosporiasis in Michigan has increased to over 170, up from 150 several days prior.

CNN - New York State, excluding New York City, has reported 107 cases of cyclosporiasis since May 1, 2026.

NBC News - 170 cases of cyclosporiasis have been reported in Michigan.

NBC News - At least 20 people have been hospitalized nationwide due to cyclosporiasis.

NBC News - The CDC reported that 145 cases of cyclosporiasis were reported in 17 U.S. states between May 1 and June 16.

NBC News - Michigan typically identifies 50 cases of cyclosporiasis per year, indicating the current outbreak is significantly above normal levels.

WHERE:

ClickOnDetroit | WDIV Local 4 - The outbreak has been confirmed in Monroe, Lenawee, Washtenaw, Wayne, Shiawassee, Jackson, and Livingston counties, as well as 11 other counties including the City of Detroit.

The Guardian - The outbreak has affected 18 states across the U.S., with New York, Texas, Illinois, and Michigan being the hardest hit.

NBC News - The outbreak is primarily located in southeast Michigan, specifically in seven counties: Monroe, Lenawee, Washtenaw, Wayne, Livingston, Shiawassee, and Jackson.

NBC News - The CDC is working with the U.S. Food and Drug Administration and local officials to investigate the outbreak.

WHEN:

NBC News - The increase in cases began to be reported since June 22, 2026.

NBC News - The CDC noted that cases of cyclosporiasis typically peak between May and August.

WHY:

NBC 5 Chicago - Health officials are investigating the outbreak due to the unusual number of cases identified in a short period, anticipating additional cases of illness being reported.

NBC News - The CDC noted that the cases currently under investigation did not report travel in the two weeks before they got sick, indicating local transmission.

NBC News - Cyclosporiasis is caused by the parasite Cyclospora cayetanensis, which spreads through contaminated food.

NBC News - The CDC is investigating potential sources of the infection, which is commonly linked to fresh produce.

HOW:

CNN - Health officials recommend thoroughly washing all fresh produce before eating, as the parasite can contaminate food through water sprayed on crops.

NBC News - Health officials recommend washing all fruits and vegetables thoroughly under running water before eating, cutting, or cooking to prevent infection.

CNN - The parasite is killed by heat, making cooking an effective method to eliminate it, but it can thrive when people opt for raw produce during warmer weather.

NBC News - Cyclosporiasis spreads through the fecal-oral route, primarily through the consumption of contaminated food or water.

NBC News - The CDC states that human-to-human transmission is highly unlikely due to the lifecycle of the parasite.

(UPDATED July 4, 2026 13:21 UTC)

Health officials are investigating an outbreak of cyclosporiasis that has led to over 300 reported cases in Southeast Michigan within just a week, with the age of those affected ranging from 8 to 84 years old and a median age of 41. The outbreak has been confirmed in multiple counties, including Monroe, Lenawee, Washtenaw, Wayne, Shiawassee, Jackson, and Livingston, as well as the City of Detroit, and more than 400 cases have been reported across 18 states. The Centers for Disease Control and Prevention noted that as of July 1, the number of cases in Michigan had increased significantly from 170 just days earlier, raising concerns about the potential for more illnesses to emerge.

(UPDATED July 4, 2026 01:26 UTC)

Health officials in Michigan are reporting over 300 cases of cyclosporiasis since June 22, 2026, with more than 170 individuals affected in just nine days. The outbreak has spread to 18 states across the U.S., with New York, Texas, Illinois, and Michigan experiencing the highest number of cases. To prevent further infections, health officials are advising everyone to thoroughly wash all fresh produce, as the parasite can contaminate food through water used on crops.

(UPDATED July 3, 2026 23:20 UTC)

The Michigan Department of Health and Human Services has reported that over 170 cases of cyclosporiasis have been identified across seven counties, with the outbreak impacting more than 100 individuals in just nine days. A detailed breakdown reveals that Monroe County has the highest number of cases at 70, followed by Lenawee with 33, and Washtenaw with 21, among others. Health officials are urging everyone to wash all fruits and vegetables thoroughly under running water before eating, cutting, or cooking to help prevent further infections.

(UPDATED July 3, 2026 19:25 UTC)

The number of reported cases of cyclosporiasis in Michigan has risen to over 170, an increase from 150 just a few days ago. Meanwhile, New York State, excluding New York City, has reported 107 cases of the illness since May 1, 2026. Health experts note that while the parasite can be eliminated by heat, it tends to thrive when people choose to eat raw produce during warmer weather.

(UPDATED July 3, 2026 17:33 UTC)

The CDC is currently investigating an outbreak of cyclosporiasis that has resulted in 170 reported cases in Michigan, with at least 20 individuals hospitalized nationwide. This outbreak, which is significantly above the typical annual average of 50 cases for the state, is primarily concentrated in southeast Michigan across seven counties. Health officials are working to identify potential sources of the infection, which is often linked to contaminated fresh produce, as the increase in cases began to be reported on June 22, 2026.