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Infectious Disease Outbreaks

Infectious Disease Outbreaks

This page provides information on current and recent infectious disease outbreaks in Michigan, including case counts, outbreak updates, and resources for the public and health care providers. 

Cyclosporiasis Outbreak 

MDHHS is investigating an outbreak of cyclosporiasis in Michigan. While the investigation is ongoing, available information indicates that lettuce or salad greens may be a potential source of this outbreak. However, other food items cannot be completely ruled out. No specific type of produce, grower, or supplier has been identified as the source. 
 
MDHHS continues to work with local health departments and partners to investigate cases and provide updates as more information becomes available.

Michigan Case Counts

Total Cases: 14,718
Hospitalizations: As of September 3, 2026, 366 reported cases indicated they had been hospitalized.
Deaths: 2

Two deaths have been identified as part of the cyclosporiasis outbreak affecting Michigan. According to medical records, both individuals had significant underlying health conditions that may have been impacted by cyclosporiasis and dehydration. The two Michigan cases became ill prior to the voluntary recall of iceberg lettuce announced by U.S Food and Drug Administration on July 17.

No additional information will be provided on these two cases.

Cyclosporiasis is generally not a life-threatening illness. Death resulting from cyclosporiasis is uncommon in the United States.

Last updated: September 6, 2026

Data notes

  • Case counts reflect all cases of cyclosporiasis reported during the outbreak investigation period and may change as additional information becomes available.
  • Case counts reflect data reported through 9:30 a.m. Eastern Time.
  • Total case counts, hospitalization status and detailed outbreak data are updated on the first Thursday of each month by 12:00 p.m. Eastern Time.

 

National cyclosporiasis case count information is available from CDC: Cyclosporiasis Surveillance.

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Detailed Outbreak Data

  • Cases by county

     

    County/Jurisdiction

    Number Cyclosporiasis Cases Reported
    Alcona 22
    Allegan 129
    Alpena 166
    Antrim 3
    Arenac 12
    Barry 45
    Bay 18
    Benzie 3
    Berrien 39
    Branch 20
    Calhoun 409
    Cass 14
    Charlevoix 5
    Cheboygan 4
    Clare 73
    Clinton 254
    Crawford 58
    Delta 2
    Detroit City 458
    Eaton 430
    Emmet 7
    Genesee 690
    Gladwin 5
    Grand Traverse 15
    Gratiot 279
    Hillsdale 71
    Houghton 2
    Huron 50
    Ingham 925
    Ionia 207
    Iosco 40
    Isabella 152
    Jackson 440
    Kalamazoo 375
    Kalkaska 7
    Kent 280
    Lake 14
    Lapeer 44
    Leelanau 2
    Lenawee 423
    Livingston 493
    Luce 1
    Macomb 535
    Manistee 6
    Marquette 5
    Mason 9
    Mecosta 39
    Midland 46
    Missaukee 1
    Monroe 405
    Montcalm 78
    Montmorency 5
    Muskegon 587
    Newaygo 83
    Oakland 1692
    Oceana 46
    Ogemaw 8
    Osceola 52
    Oscoda 5
    Otsego 3
    Ottawa 210
    Presque Isle 13
    Roscommon 14
    Saginaw 105
    Sanilac 44
    Shiawassee 503
    St. Clair 31
    St Joseph 52
    Tuscola 22
    Van Buren 156
    Washtenaw 1115
    Wayne 2158
    Wexford 2

    Last Update: September 3, 2026

    Data notes

    • Case counts reflect all cases of cyclosporiasis reported during the outbreak investigation period and may change as additional information becomes available.
    • One (1) reported cases have an unknown county of residence. As a result, the total shown in the county distribution may not equal the overall case count.
    • Case counts reflect data reported through 9:30 a.m. Eastern Time.
    • Cases by county are updated on the first Thursday of each month by 12:00 p.m. Eastern Time.

     

  • Cases by age group

     

    Age Group

    Number of Cases
    0-9 years 98
    10-19 years 860
    20-29 years 2,458
    30-39 years 2,992
    40-49 years 2,641
    50-59 years 2,238
    60-69 years 1,919
    70-79 years 1,122
    80-89 years 351
    90 years and above 33

    Last update: September 3, 2026

    Data notes

    • Case counts reflect all cases of cyclosporiasis reported during the outbreak investigation period and may change as additional information becomes available.
    • Three (3) cases have an unknown age. As a result, the total shown in the age distribution may not equal the overall case count.
    • Case counts reflect data reported through 9:30 a.m. Eastern Time.
    • Cases by age group are updated on the first Thursday of each month by 12:00 p.m. Eastern Time.

  • Cases by date reported

    This graph shows the cyclosporiasis cases reported to MDHHS from June 22, 2026, through 9:30 a.m. September 3, 2026.

    This graph shows the cyclosporiasis cases reported to MDHHS from June 22, 2026, through 9:30 a.m. September 3, 2026. Noting July 19 and August 2 inflated cases.  

    Last update: September 3, 2026

    Data notes

    • Case counts reflect all cases of cyclosporiasis reported during the outbreak investigation period and may change as additional information becomes available.
    • The July 19, 2026 reported week includes approximately 475 cases that were not previously reported to MDHHS due to delayed laboratory reporting. These cases do not reflect a sudden increase in illnesses.
    • The August 2, 2026 reported week includes approximately 473 cases that were not previously reported to MDHHS due to delayed laboratory reporting. These cases do not reflect a sudden increase in illnesses.
    • Cases by date reported are updated on the first Thursday of each month by 12:00 p.m. Eastern Time.

  • Cases by illness onset

    This graph shows the week of illness onset for cyclosporiasis cases reported to MDHHS from May 10, 2026, through September 3, 2026.

     This graph shows the week of illness onset for cyclosporiasis cases reported to MDHHS from May 10, 2026, through September 3, 2026. 

    Last update: September 3, 2026

    Data notes

    • Case counts reflect all cases of cyclosporiasis reported during the outbreak investigation period and may change as additional information becomes available.
    • Cases by illness onset are updated on the first Thursday of each month by 12:00 p.m. Eastern Time.

This is an active and evolving situation, these recommendations may change as more information becomes available.

Recommended actions for individuals who think they may have cyclosporiasis:

People experiencing gastrointestinal illness, such as sudden and ongoing diarrhea, are encouraged to contact their health care provider for testing and treatment. For general questions about the cyclosporiasis outbreak, contact your local health department. Cyclosporiasis is treated with antibiotics along with rest and drinking plenty of fluids to maintain hydration.

Recommended practices for all individuals serving, preparing or consuming lettuce and salad greens in impacted counties:

Michigan residents may resume routine guidance for consuming lettuce and salad greens as new cyclosporiasis case reports and related emergency department visits are on the decline.

General practices to reduce your risk of cyclosporiasis and other foodborne illnesses:

  • Cook when you can. Heating food to 158°F (70°C) or higher kills Cyclospora.
  • Peel produce. Peeling is highly effective for food items with removable skin as the parasite sits on the outer surface.
  • Wash all fresh produce under clean running water, even if you plan to peel it.
    • “Pre-washed” does not guarantee safety and rewashing bagged lettuce is unlikely to remove cyclospora. While washing alone may not fully eliminate cyclospora, it enhances protection when combined with cooking or peeling. 

Additional food safety reminders:

  • Wash hands with soap and water before and after handling or preparing food.
  • Scrub firm fruits and vegetables, such as melons and cucumbers, with a clean produce brush.
  • Cut away any damaged or bruised areas on fruits and vegetables before preparing and eating.
  • Wash and sanitize utensils and surfaces before and after handling food. Wash and sanitize display cases and refrigerators where fresh produce is stored.
  • Wash and sanitize cutting boards, surfaces and utensils used to prepare, serve or store fresh produce.
  • Refrigerate cut, peeled or cooked fruits and vegetables as soon as possible. 

Salmonella Outbreak

MDHHS is aware of a multistate Salmonella Javiana outbreak. For additional information about the outbreak, including case updates, investigation details, and recall information, see the CDC and FDA advisories below.

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