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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: 14,277
Hospitalizations: As of August 20, 2026, 335 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: August 20, 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 weekly on Thursdays by 11:00 a.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 160
    Antrim 3
    Arenac 12
    Barry 43
    Bay 18
    Benzie 3
    Berrien 36
    Branch 20
    Calhoun 406
    Cass 14
    Charlevoix 5
    Cheboygan 3
    Clare 69
    Clinton 247
    Crawford 58
    Delta 2
    Detroit City 432
    Eaton 425
    Emmet 5
    Genesee 653
    Gladwin 5
    Grand Traverse 15
    Gratiot 279
    Hillsdale 71
    Houghton 2
    Huron 50
    Ingham 921
    Ionia 202
    Iosco 39
    Isabella 148
    Jackson 432
    Kalamazoo 369
    Kalkaska 7
    Kent 274
    Lake 14
    Lapeer 39
    Leelanau 2
    Lenawee 419
    Livingston 484
    Luce 1
    Macomb 503
    Manistee 6
    Marquette 4
    Mason 9
    Mecosta 38
    Midland 45
    Missaukee 1
    Monroe 401
    Montcalm 76
    Montmorency 5
    Muskegon 583
    Newaygo 81
    Oakland 1538
    Oceana 45
    Ogemaw 8
    Osceola 51
    Oscoda 5
    Otsego 3
    Ottawa 207
    Presque Isle 13
    Roscommon 14
    Saginaw 105
    Sanilac 44
    Shiawassee 495
    St. Clair 31
    St Joseph 52
    Tuscola 23
    Van Buren 150
    Washtenaw 1105
    Wayne 2095
    Wexford 2

    Last Update: August 20, 2026

    Data notes

    • Case counts reflect all cases of cyclosporiasis reported during the outbreak investigation period and may change as additional information becomes available.
    • Two (2) 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 weekly on Thursdays.

     

  • Cases by age group

     

    Age Group

    Number of Cases
    0-9 years 94
    10-19 years 843
    20-29 years 2,409
    30-39 years 2,937
    40-49 years 2,571
    50-59 years 2,153
    60-69 years 1,830
    70-79 years 1,076
    80-89 years 326
    90 years and above 32

    Last update: August 20, 2026

    Data notes

    • Case counts reflect all cases of cyclosporiasis reported during the outbreak investigation period and may change as additional information becomes available.
    • Six (6) 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 weekly on Thursdays.

  • Cases by date reported

    This graph shows the cyclosporiasis cases reported to MDHHS from June 22, 2026, through 9:30 a.m. August 20, 2026.

    This graph shows the cyclosporiasis cases reported to MDHHS from June 22, 2026, through 9:30 a.m. August 20, 2026. Noting July 19 and August 2 inflated cases.

     

    Last update: August 20, 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 weekly on Thursdays.

  • Cases by illness onset

    This graph shows the week of illness onset for cyclosporiasis cases reported to MDHHS from May 10, 2026, through August 20, 2026.

     This graph shows the week of illness onset for cyclosporiasis cases reported to MDHHS from May 10, 2026, through August 17, 2026.

    Last update: August 20, 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 weekly on Thursdays.

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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