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Past Outbreaks in Wisconsin

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Archived outbreaks and investigations

Below is a list of past outbreaks and investigations with wide impact in Wisconsin.

For current outbreaks and investigations, please visit our Outbreaks in Wisconsin page.

2023 Outbreaks

The Wisconsin Department of Health Services (DHS), along with the Department of Agriculture, Trade, and Consumer Protection (DATCP), local health departments, and federal partners, worked to investigate a multistate outbreak of Salmonella infections linked to cantaloupe.

  • According to the CDC (Centers for Disease Control and Prevention), 407 people in 44 states were infected with the outbreak strain of Salmonella. One hundred fifty-eight people were hospitalized and six deaths were reported.
  • Wisconsin had 29 laboratory-confirmed cases in 17 counties linked to this outbreak. Nine people were hospitalized and zero deaths were reported.

As of January 19, 2024, CDC declared this outbreak to be over.

Recall information

All recalls that resulted from this investigation are listed on the Food and Drug Administration’s (FDA) cantaloupe recall website. Recalled cantaloupes are no longer available for sale and the use-by dates have passed

Advice to consumers

DHS and CDC urge people to take the following steps:

Always follow four food safety steps to prevent getting sick from Salmonella:

  • Clean: Wash your hands, utensils, and surfaces often.
  • Separate: Keep food that won’t be cooked separate from raw meat, poultry, and seafood.
  • Cook: Use a food thermometer to make sure you have cooked your food to a temperature high enough to kill germs.
  • Chill: Refrigerate perishable food (food that goes bad) within 2 hours. If the food is exposed to temperatures above 90°F (like a hot car or picnic), refrigerate it within 1 hour. Thaw food in the refrigerator, not on the counter.

See the FDA and CDC webpages for more information on this investigation, and to stay up to date on other food-borne outbreaks and recalls:

CDC: Salmonella Outbreak Linked to Cantaloupes

FDA: Outbreak Investigation of Salmonella - Cantaloupes

CDC: Salmonella and Food

CDC: Fruit and Vegetable Safety

The Wisconsin Department of Health Services (DHS) worked with state and federal partners to investigate a multistate outbreak of Listeria monocytogenes infections linked to leafy greens.

  • According to the CDC (Centers for Disease Control and Prevention), 19 people in 16 states became infected with the outbreak strain of Listeria. Eighteen people were hospitalized and zero deaths were reported
  • Wisconsin had two laboratory-confirmed cases and zero deaths linked to this outbreak.

Epidemiologic evidence indicated that leafy greens were a likely source of this outbreak, but there was not enough information to determine a specific type or produce.

As of June 13, 2023, CDC declared this outbreak to be over.

Advice to consumers

DHS and CDC urge people to take the following steps:

  • Stay healthy and prevent Listeria
    • People aged 65 and older, pregnant people and their newborns, and people who have weakened immune systems are at a higher risk of becoming sick from Listeria.
    • Learn about which foods are more likely to contain Listeria and steps to take to prevent illness.
    • Stay informed on food recalls and outbreaks to avoid getting sick.
  • Prepare leafy greens safely
    • Wash your hands, utensils, and food preparation surfaces before and after preparing leafy greens.
    • Clean leafy greens before eating or cutting them:
      • Discard outer leaves on whole heads of lettuce. Discard any torn or bruised leaves.
      • Use your hands to gently rub the surface of the leaves as you rinse them under running water, then dry leaves with a clean cloth or paper towel.
      • If the label on a leafy greens package says “ready to eat,” “triple washed,” or “no washing necessary,” you don’t need to wash the greens.
    • Keep leafy greens separate from raw meat, poultry, and seafood. These can contain germs that can contaminate leafy greens.
    • Refrigerate leafy greens within two hours, within one hour if they have been exposed to temperatures above 90°F.

See the Food and Drug Administration (FDA) and CDC webpages for more information on this investigation, and to stay up to date on other food-borne outbreaks and recalls:

CDC: Listeria Outbreak CDC webpage

FDA: Investigations of Foodborne Illness Outbreaks

CDC: Listeria: Questions and Answers

The Wisconsin Department of Health Services (DHS) worked with local, state, and federal partners to investigate multiple outbreaks of Salmonella infections linked to contact with backyard poultry.

  • Between January 1 and September 25, 2023, the CDC reported that 1,072 people, in 48 states and Puerto Rico were infected with one of the outbreak strains of Salmonella.
  • In Wisconsin since March 2023, 41 people were infected with one of the outbreak strains of Salmonella.
  • Among Wisconsinites with infections linked to the national outbreak:
    • Case patients resided in 31 counties across the state.
    • Seven infections resulted in hospitalization. No deaths were reported.
    • Case patients range in age from under 1 year to 75 years, with an average age of 32 years.

CDC ended the annual investigation of outbreaks linked to backyard poultry on October 19, 2023. Outbreaks of Salmonella linked to backyard poultry occur every year in the U.S., including in Wisconsin residents. Many of these infections are preventable.

  • Poultry, including healthy and clean backyard poultry, can have Salmonella germs in their poop and on their bodies (feathers, feet, and beaks). The germs can easily spread to their cages, coops, eggs, and equipment used to care for them. People can get sick from Salmonella if they touch the birds or anything in their environment and then touch their mouth or food before washing their hands.
  • Children younger than 5 years are more likely to get sick with Salmonella because their immune systems are still developing. They also are more likely to put their fingers or other items with germs into their mouths.

People who own or have contact with poultry can take these steps to reduce the risk of becoming ill with salmonellosis:

  • Always wash your hands after touching backyard poultry, their eggs, or anything within the areas in which they live or roam.
  • Don’t kiss or snuggle backyard poultry, and don’t eat or drink around them.
  • Supervise kids around flocks and don’t let children younger than 5 years touch chicks, ducklings, or other backyard poultry.
  • Handle eggs safely.
  • Call your healthcare provider right away if you have any of these severe symptoms:
    • Diarrhea and a fever higher than 102°F
    • Diarrhea for more than 3 days that is not improving
    • Bloody stools
    • Prolonged vomiting that prevents you from keeping liquids down
    • Signs of dehydration, such as:
      • Making very little urine
      • Dry mouth and throat
      • Dizziness when standing up

For more information about how to reduce your risk of getting sick:

See the CDC webpage for more information on this investigation, and to stay up to date on other food-borne outbreaks and recalls:

CDC: Salmonella Outbreaks Linked to Backyard Poultry

2022 Outbreaks

The Wisconsin Department of Health Services (DHS) is worked with local, state, and federal partners to investigate multiple outbreaks of Salmonella infections linked to contact with live backyard poultry.

  • Between February 12 and October 18, 2022, the CDC reported that 1,230 people from 49 states, the District of Columbia, and Puerto Rico were infected with one of the outbreak strains of Salmonella.
  • Children younger than 5 years accounted for 21% of the illnesses nationally.
  • In Wisconsin since March 2022, 53 people were infected with one of the outbreak strains of Salmonella.
  • Among Wisconsinites with infections linked to the national outbreak:
    • Case patients resided in 39 counties or tribal lands across the state.
    • Seven infections resulted in hospitalization. No deaths were reported.
    • Infections occurred in people ranging from under 1 to 72 years of age, with an average age of 37 years. Children less than 5 years of age accounted for less than 10% of infections.

CDC ended the annual investigation of outbreaks linked to backyard poultry on November 10, 2022. Outbreaks of Salmonella infections linked to contact with backyard poultry occur every year in the U.S., including in Wisconsin residents. Many of these infections are preventable.

  • Poultry, including healthy and clean backyard poultry, can have Salmonella germs in their poop and on their bodies (feathers, feet, and beaks). The germs can easily spread to their cages, coops, eggs, and equipment used to care for them. People can get sick from Salmonella if they touch the birds or anything in their environment and then touch their mouth or food before washing their hands.
  • Children younger than 5 years are more likely to get sick with Salmonella because their immune systems are still developing. They also are more likely to put their fingers or other items with germs into their mouths.

People who own or have contact with poultry can take these steps to reduce the risk of becoming ill with salmonellosis:

  • Always wash your hands after touching backyard poultry, their eggs, or anything within the areas in which they live or roam.
  • Don’t kiss or snuggle backyard poultry, and don’t eat or drink around them.
  • Supervise kids around flocks and don’t let children younger than 5 years touch chicks, ducklings, or other backyard poultry.
  • Handle eggs safely.
  • Call your healthcare provider right away if you have any of these severe symptoms:
    • Diarrhea and a fever higher than 102°F
    • Diarrhea for more than 3 days that is not improving
    • Bloody stools
    • Prolonged vomiting that prevents you from keeping liquids down
    • Signs of dehydration, such as:
      • Making very little urine
      • Dry mouth and throat
      • Dizziness when standing up

For more information about how to reduce your risk of getting sick:

See the CDC webpage for more information on this investigation, and to stay up to date on other food-borne outbreaks and recalls:

CDC: Salmonella Outbreaks Linked to Backyard Poultry

The Wisconsin Department of Health Services (DHS) worked with the Department of Agriculture, Trade, and Consumer Protection (DATCP) and local health departments to investigate cases of Salmonella associated with shelled peas produced by Green Barn Farm Market. The shelled (loose) peas were sold at Green Barn Farm Market farm stands and farmers markets in Ripon, Green Bay, Madison, and Fond du Lac, and Green Valley Acres Farm farm stands in Neenah.

  • As of October 1, 2022, 22 people were infected with two outbreak strains of Salmonella.
  • Four people required hospitalization for their illnesses.

The source of contamination on the farm was not identified.

Resources

The Wisconsin Department of Health Services (DHS) worked with state and federal partners to investigate a multistate outbreak of Salmonella infections linked to pet bearded dragons.

  • As of June 16, 2022 the CDC (Centers for Disease Control and Prevention) reports 56 people in 26 states have been infected. Fifteen people have been hospitalized. No deaths were reported.
  • Wisconsin had five laboratory-confirmed cases linked to this outbreak.
  • On June 16, 2022 CDC declared this outbreak investigation closed.

Bearded dragons can carry Salmonella germs in their droppings even if they look healthy and clean. These germs can easily spread to their bodies and anything in the area where they live and roam.

You can get sick from touching your bearded dragon or anything in its environment and then touching your mouth and swallowing Salmonella germs.

DHS and CDC continue to urge people to take the following steps:

  • Wash your hands.
    • Always wash hands thoroughly with soap and water right after touching or feeding your bearded dragon and after touching or cleaning the area where it lives and roams.
    • Adults should make sure young children are washing their hands.
  • Play safely.
    • Don’t kiss or snuggle your bearded dragon, and don’t eat or drink around it. This can spread Salmonella germs to your mouth and make you sick.
    • Keep your bearded dragon out of your kitchen and other areas where you eat, store, or prepare food.
  • Keep things clean.
    • Clean your bearded dragon supplies outside the house, if possible. These supplies may include its feeders, toys, and food and water containers.
    • If you clean the supplies indoors, don’t clean them in the kitchen or other areas where you eat or prepare food. Use a laundry sink or bathtub, and thoroughly clean and disinfect the area right after.

If you are thinking of getting a pet bearded dragon pick the right pet for your family.

Bearded dragons and other reptiles are not recommended for children younger than 5, adults aged 65 and older, and people with weakened immune systems. These people are more likely to get a serious illness from germs that reptiles can carry.

Call your health care provider right away if you have any of these severe Salmonella symptoms:

  • Diarrhea and a fever higher than 102°F
  • Diarrhea for more than three days that is not improving
  • Bloody diarrhea
  • So much vomiting that you cannot keep liquids down
  • Signs of dehydration, such as:
  • Not peeing much
  • Dry mouth and throat
  • Feeling dizzy when standing up

See the CDC webpages for more information on this investigation, and to stay up to date on other foodborne outbreaks and recalls:

The Wisconsin Department of Health Services (DHS) is working with state and federal partners to investigate a multistate outbreak of Listeria monocytogenes infections linked to packaged salads produced by Dole.

  • As of April 4, 2022, CDC reported, 18 people in 13 states were infected with the outbreak strain of Listeria. Sixteen people were hospitalized, and three deaths were reported.
  • Wisconsin has one laboratory-confirmed death linked to this outbreak.

Product and recall information

Epidemiologic evidence and product traceback indicated that packaged salads produced by Dole was the source of this outbreak

On December 22, 2021, Dole recalled all Dole-branded and private label packaged salads processed at their Bessemer City, North Carolina, and Yuma, Arizona, facilities. Then on January 7, 2022, Dole recalled additional products containing iceberg lettuce harvested by the contaminated harvesting equipment. Recalled products are past their shelf life and should no longer be available in stores.

As of April 4, 2022, CDC declared this outbreak to be over.

Resources

See the FDA and CDC webpages for more information on this investigation, and to stay up to date on other foodborne outbreaks and recalls:

The U.S. Food and Drug Administration (FDA), along with the CDC (Centers for Disease Control and Prevention), are investigating consumer complaints of infant illness received from September 20, 2021, to January 11, 2022, related to powdered infant formula products from the Abbott Nutrition facility in Sturgis, MI. All of the cases are reported to have consumed powdered infant formula produced at this facility. These complaints include four reports of Cronobacter sakazakii infections. All four cases related to these complaints were hospitalized, and Cronobacter infection may have contributed to two deaths. No Wisconsin cases of Cronobacter sakazakii linked to recalled powdered infant formula have been identified at this time.

As of March 11, 2022, the Salmonella Newport illness previously included in this investigation of complaints and illnesses has been removed. After further investigation, the FDA has determined that there is not enough information to definitively link this illness to powdered infant formula. CDC confirmed that this single Salmonella illness is not linked to an outbreak.

As of May 24, 2022, CDC declared this investigation to be closed.

Product and recall information

See the FDA recall.

The FDA advises consumers not to use recalled Similac, Alimentum or EleCare (including EleCare Jr.) powdered infant formulas. Recalled products can be identified by the 7- to 9-digit code and expiration date on the bottom of the package (see image below). Products are included in the recall if they have all three items below:

  • The first two digits of the code are 22 through 37, and
  • The code on the container contains K8, SH, or Z2, and
  • The expiration date is 4-1-2022 (APR 2022) or later.

In addition to products described above, Abbott Nutrition has recalled Similac PM 60/40 with a lot code 27032K80 (can) / 27032K800 (case). At this time Similac PM 60/40 with lot code 27032K80 (can) / 27032K800 (case) are the only type and lots of this specialty formula being recalled.

Additional recall information is available on the FDA website. Parents can also enter their product lot code on the company’s website to check if it is part of the recall. Do not feed infants recalled powdered formula.

Information for parents

Do not feed your baby any recalled powdered formula.

  • If you feed your baby with other types of Similac PM 60/40 powdered formula:
    • Check for the lot code 27032K800 that is included in the expanded recall.
    • At this time, Similac PM 60/40 with lot code 27032K80 (can) / 27032K800 (case) is the only type and lot of this specialty formula being recalled.
    • To find out if the product you have is included in this recall, review product lot code on the bottom of the package and enter it on Abbott Nutrition’s website.
  • If you feed your baby with other types of Similac, Alimentum, or EleCare powdered formula:
    • Check to see if your powdered formula is recalled using one of these three ways:
      • Compare the lot code and use-by date on the bottom of the package to the recall information.
      • Visit Abbott Nutrition’s website and type in the code on the bottom of the package.
      • Call 1-800-986-8540 and follow the instructions provided.
  • If you get infant formula through Wisconsin Women, Infants, and Children (WIC) program, do not throw the formula out.
    • Exchange the recalled formula at the store if unaffected product is available. Stores may be limiting the number of cans you can exchange. Stores may have removed all formula to sort out those affected by the recall and will replace soon.
    • If a replacement for recalled formula is not available at the store, do not leave the recalled formula at the store or discard it:
      • Contact your local WIC office
      • Complete the Similac recall process at www.similacrecall.com or call 1-800-986-8540
      • Use FoodShare or other means to purchase formula
    • For more information from Wisconsin WIC, please visit their page.
  • If you have any recalled powdered formula, immediately stop feeding it to your baby and return it for a refund at the store where you bought it. You can also return it to Abbott Nutrition.
  • If you can’t find the code on the powdered formula package, do not use it.
  • Contact your baby’s health care provider if:
    • Your baby has symptoms of Cronobacter illness (fever and poor feeding, excessive crying, or very low energy).
    • Your regular formula is not available, and you need recommendations on other ways to feed your baby.

Please review the links below for more information about the recall of powdered infant formula due to potential bacterial contamination, including Cronobacter sakazakii.

The Wisconsin Department of Health Services (DHS) worked with local health departments, the Wisconsin Department of Agriculture, Trade, and Consumer Protection (DATCP), the CDC (Centers for Disease Control and Prevention), and the U.S. Food and Drug Administration (FDA) to investigate a multistate outbreak of Salmonella Oranienburg infections linked to the consumption of onions.

  • According to the CDC, 1,040 people in 39 states, Puerto Rico, and the District of Columbia were infected with the outbreak strain of Salmonella. Two-hundred sixty people were hospitalized and no deaths were reported.
  • Wisconsin had 31 laboratory-confirmed cases linked to this outbreak, and at least 8 were hospitalized.

Multiple companies recalled onions in response to this outbreak. All recalled onions were supplied by ProSource Produce LLC and Keeler Family Farms and imported from the State of Chihuahua, Mexico, between July 1, 2021, and August 31, 2021. FDA’s website has a table with information about each company’s recall.

On February 2, 2022 the CDC declared this outbreak to be over, and recalled onions and products should no longer be available in grocery stores. However, onions have a long shelf-life and may still be in homes or freezers.

DHS and CDC continue to urge people to take the following steps:

  • If you have recalled onions, do not eat them. Throw them away.
  • Wash items and surfaces that may have touched the recalled product using hot soapy water or a dishwasher.

See the FDA and CDC webpages for more information on this investigation, and to stay up to date on other food-borne outbreaks and recalls:

2021 Outbreaks

The Wisconsin Department of Health Services (DHS) worked with local, state, and federal partners to investigate multiple outbreaks of Salmonella infections linked to contact with live backyard poultry.

  • As of November 18, 2021, the CDC reported that 1,135 people, in 48 states, the District of Columbia, and Puerto Rico were infected with one of the outbreak strains of Salmonella.
  • Children younger than 5 years accounted for 24% of the illnesses nationally.
  • In Wisconsin since March 2021, 73 people were infected with one of the outbreak strains of Salmonella.
  • Among Wisconsinites with infections linked to the national outbreak:
    • Cases resided in 37 counties across the state.
    • 27% (n=20) of infections resulted in hospitalization. No deaths were reported.
    • Infections occurred in people ranging from 0 to 86 years of age, with the average age of 37 years. Children less than 5 years of age accounted for 23% of infections.

CDC ended the investigation of outbreaks linked to backyard poultry on November 18, 2021. Outbreaks of Salmonella infections linked to contact with backyard poultry occur every year in the U.S., including in Wisconsin residents. Many of these infections are preventable.

  • Poultry, including healthy and clean backyard poultry, can have Salmonella germs in their poop and on their bodies (feathers, feet, and beaks). The germs can easily spread to their cages, coops, eggs, and equipment used to care for them. People can get sick from Salmonella if they touch the birds or anything in their environment and then touch their mouth or food before washing their hands.
  • Children younger than 5 years are more likely to get sick with Salmonella because their immune systems are still developing. They also are more likely to put their fingers or other items with germs into their mouths.

Quick tips for what backyard owners should do (See CDC webpage for more details)

  • Always wash your hands after touching backyard poultry, their eggs, or anything within the areas in which they live or roam.
  • Don’t kiss or snuggle backyard poultry, and don’t eat or drink around them.
  • Supervise kids around flocks and don’t let children younger than 5 years touch chicks, ducklings, or other backyard poultry.
  • Handle eggs safely.
  • Call your healthcare provider right away if you have any of these severe symptoms:
    • Diarrhea and a fever higher than 102°F
    • Diarrhea for more than 3 days that is not improving
    • Bloody stools
    • Prolonged vomiting that prevents you from keeping liquids down
    • Signs of dehydration, such as:
      • Making very little urine
      • Dry mouth and throat
      • Dizziness when standing up

For more information about how to reduce your risk of getting sick:

See the CDC webpage for more information on this investigation, and to stay up to date on other food-borne outbreaks and recalls:

CDC: Salmonella Outbreaks Linked to Backyard Poultry

The Wisconsin Department of Health Services (DHS) worked with local health departments, the CDC (Centers for Disease Control and Prevention), and the U.S. Department of Agriculture (USDA) to investigate a multistate outbreak of Salmonella Typhimurium and Salmonella Infantis infections linked to the consumption of Fratelli Beretta brand Italian-style meats.

  • According to the CDC, 40 people in 17 states were infected with the outbreak strains of Salmonella. Twelve people were hospitalized and no deaths were reported.
  • Wisconsin had one laboratory-confirmed case linked to this outbreak.

Information collected during this investigation indicated that Fratelli Beretta brand prepackaged uncured antipasto trays were the likely source of this outbreak.

On August 27, 2021, Fratelli Beretta voluntarily recalled an uncured antipasto product. Packaging details of the recalled products:

  • Fratelli Beretta Uncured Antipasto prosciutto, soppressata, Milano salami and coppa 24-oz trays containing two 12-oz packages with “best by” dates on or before February 11, 2022 (UPC code 073541305316)
  • Have the establishment number “EST. 7543B” inside the U.S. Department of Agriculture’s mark of inspection. See recall notice for more details.

On October 26, 2021, the CDC declared this outbreak to be over. However, because of the long shelf life of these products, the CDC continues to advise people not to eat any Fratelli Beretta brand Uncured Antipasto trays with “best by” dates on or before February 11, 2022.

DHS and CDC urge people to take the following steps:

  • Check your home for the antipasto trays described in this health advisory. Throw any remaining product away, even if some of it has been eaten and no one has gotten sick.
  • If you don’t know the brand of prepackaged Italian-style meats you have at home, don’t eat them and throw them away.
  • Wash items, containers, and surfaces that may have touched the products using hot soapy water or a dishwasher.

See the FDA and CDC webpages for more information on this investigation, and to stay up to date on other food-borne outbreaks and recalls:

The Wisconsin Department of Health Services (DHS) worked with local health departments, the Wisconsin Department of Agriculture, Trade, and Consumer Protection (DATCP), the CDC (Centers for Disease Control and Prevention), and the U.S. Food and Drug Administration (FDA) to investigate a multistate outbreak of Salmonella Typhimurium infections linked to the consumption of pre-packaged salad greens produced by BrightFarms of Rochelle, IL.

  • According to the CDC, 31 people in four states were infected with the outbreak strain of Salmonella Typhimurium. Four people were hospitalized and no deaths were reported.
  • In Wisconsin, 10 laboratory-confirmed cases were linked to this outbreak.

Information collected during this investigation indicated that BrightFarms pre-packaged salad greens were the likely source of this outbreak.

On July 15, 2021 BrightFarms voluntarily recalled packaged salad greens produced in its Rochelle, Illinois greenhouse farm. BrightFarms expanded this voluntary recall on July 21 and 28, 2021.

On October 6, 2021, the CDC declared this outbreak to be over.

See the FDA and CDC webpages for more information on this investigation, and to stay up to date on other food-borne outbreaks and recalls:

2020 Outbreaks

The Wisconsin Department of Health Services (DHS) worked with local, state, and federal partners to investigate a multistate outbreak of Salmonella Enteritidis infections linked to peaches.

  • CDC reported 101 people in 17 states were infected with the outbreak strain of Salmonella Enteritidis. Twenty-eight people were hospitalized and no deaths were reported.
  • Wisconsin had six laboratory-confirmed cases linked to this outbreak. One case was hospitalized.

Epidemiologic and traceback evidence indicated that peaches packed or supplied by Prima Wawona or Wawona Packing Company were the likely source of this outbreak.

On August 22, 2020, Prima Wawona recalled bagged and bulk, or loose, peaches that they supplied to retailers nationwide. See FDA’s notice for a list of recalled products. Recalled products are past their shelf life and should no longer be available in stores.

As of October 16, 2020, CDC declared this outbreak to be over.

See the FDA and CDC webpages for more information on this investigation, and to stay up to date on other food-borne outbreaks and recalls:

The Wisconsin Department of Health Services (DHS) worked with local, state, and federal partners to investigate a multistate outbreak of Salmonella Newport infections linked to the consumption of onions.

  • As of October 8, 2020, CDC reported that 1,127 people in 48 states were infected with the outbreak strain of Salmonella Newport. There were 167 people hospitalizations and no deaths.
  • Wisconsin had 11 laboratory-confirmed cases linked to this outbreak. Two cases were hospitalized.

Epidemiologic and traceback evidence showed that red onions from Thomson International Inc. were the likely source of this outbreak. Other onion types (such as white, yellow, or sweet yellow) were also likely to be contaminated because the onions were grown and harvested together.

On August 1, 2020, Thomson International Inc. recalled all red, yellow, white, and sweet yellow onions because they may be contaminated with Salmonella. See FDA’s notice for a list of recalled products. Recalled products are past their shelf life and should no longer be available in stores.

As of October 8, 2020, CDC declared this outbreak to be over.

See the FDA and CDC webpages for more information on this investigation, and to stay up to date on other food-borne outbreaks and recalls:

The Wisconsin Department of Health Services (DHS) worked with local, state, and federal partners to investigate a multistate outbreak of cyclosporiasis infections linked to the consumption of bagged salad mix containing iceberg lettuce, carrots, and red cabbage produced by Fresh Express.

  • As of September 23, 2020, CDC reported a total of 701 people with laboratory-confirmed Cyclospora infections associated with this outbreak have been reported from 13 states. 38 people have been hospitalized and no deaths have been reported.
  • Wisconsin had 48 laboratory confirmed cases linked to this outbreak. One case was hospitalized.

Epidemiologic evidence and product traceback indicated that bagged salad mix containing iceberg lettuce, carrots, and red cabbage produced by Fresh Express was a likely source of this outbreak.

Fresh Express recalled Fresh Express brand and private label brand salad products produced at its Streamwood, IL facility that contained iceberg lettuce, red cabbage, and/or carrots on June 27, 2020. Recalled products are past their shelf life and should no longer be available in stores.

As of September 23, 2020, CDC declared this outbreak to be over.

See the FDA and CDC webpages for more information on this investigation, and to stay up to date on other food-borne outbreaks and recalls:

2019 Outbreaks

Fresh Express Sunflower Crisp chipped lettuce kit

  • The Wisconsin Department of Health Services (DHS) is working with local health departments, the CDC (Centers for Disease Control and Prevention), and college and university health services directors in our state to track multiple outbreaks of respiratory illness caused by adenoviruses and to provide prevention information to students and staff.
  • People usually get sick with adenoviruses when they spend time with large groups of people (for example, at universities, hospitals, or schools). There are over 50 different types of adenoviruses. Usually adenoviruses cause mild illness, but sometimes they can be serious. The types of symptoms you have depend on which type of adenovirus you have and the part of the body that the virus is affecting.
    • Adenoviruses most commonly cause respiratory illness, which can range from cold and flu-like symptoms to bronchitis and pneumonia.
    • Some adenoviruses can cause diarrhea or pink eye, and in rare cases, inflammation of the bladder or severe neurological disease.
    • Anyone can get sick from an adenovirus. People with a weakened immune system, or those who have lung or heart problems are more likely to become very sick from an adenovirus.
    • Antibiotics do not work against adenoviruses.
  • There are a number of ways you can get an adenovirus:
  1. Breathing in adenovirus from the air: someone with the virus coughs or sneezes and the virus gets into the air. It is then breathed in by someone around them.
  2. Having direct contact with someone who has an adenovirus: touching or shaking hands with someone who has the virus on their skin and then touching your hands to your mouth, nose, or eyes.
  3. Touching surfaces with adenovirus: touching a surface (for example, a door knob, counter top, or phone) with adenovirus on it and then touching your hands to mouth, nose, or eyes. NOTE: Adenoviruses are able to survive on surfaces for a long time. It is important to wash toys, towels, and other surfaces often to make sure it doesn't spread to others.
  4. Having contact with poop: Some adenoviruses can spread through poop, for example, during diaper changing.
  5. Having contact with water that has adenovirus: Adenoviruses can also spread through water, such as swimming pools, but this is less common.

NOTE: Sometimes the virus can be shed (released from the body) for a long time after you recover from an adenovirus, especially if you have a weakened immune system. Usually you do not have any symptoms during this time of “virus shedding,” even though you can still spread adenovirus to others.

  • The best ways to prevent the spread of adenoviruses are to:
    • Wash your hands often with soap and water for at least 20 seconds.
    • Do not touch your eyes, nose, or mouth with unwashed hands.
    • Do not have close contact with people who are sick.
  • Additional information can be found at the following websites:

  • The Wisconsin Department of Health Services (DHS) is working with local health departments, the Wisconsin Department of Agriculture, Trade, and consumer Protection (DATCP), the CDC (Centers for Disease Control and Prevention), and the U.S. Food and Drug Administration (FDA) to investigate a multistate outbreak of E. coli O157:H7 infections linked to romaine lettuce.
    • As of December 19, 2019, the CDC reports that 138 people in 25 states are infected with the outbreak strain of STEC. There have been 72 people hospitalized and 13 cases of hemolytic uremic syndrome (HUS), a type of kidney failure. No deaths have been reported.
    • As of December 19, 2019, Wisconsin has 33 confirmed cases linked to this outbreak. Of these, 14 people have been hospitalized and 2 have developed HUS.
  • Epidemiologic, laboratory, and traceback evidence collected so far shows that romaine lettuce from the Salinas, California, growing region is a likely source of this outbreak.
    • On November 21, 2019, a list of salad products were recalled after laboratory testing found the same strain of E. coli that was making people sick in Maryland in romaine lettuce harvested from the Salinas, California growing region.
    • On December 6, 2019, Wisconsin health officials found E. coli O157 in an unopened bag of chopped Fresh Express® brand Leafy Green Romaine salad from Salinas, California that was collected from an ill person’s home. On December 13, 2019, specialized laboratory testing called whole genome sequencing showed that the E. coli O157 strain found in the romaine matches the outbreak strain of E. coli that has made people in Wisconsin and other states sick.
    • While E. coli O157 was found in a bag of chopped Fresh Express® brand romaine, not all ill people in Wisconsin included in this outbreak report eating Fresh Express® brand romaine. No single brand, product, or type of romaine lettuce has been reported by all ill individuals. The investigation is ongoing to determine the source of contamination and if additional products are linked to illness.
  • Wisconsin DHS, the CDC, and FDA are advising people not to eat, sell, or serve any romaine lettuce harvested from Salinas, California, until more information is available.
  • While certain romaine-containing products were recalled, many romaine lettuce and romaine-containing products are still available on store shelves.
  • Advice to Consumers, Retailers, and Restaurants:
    • Most romaine lettuce products are labeled with a harvest location showing where they were grown. This advice includes all types of romaine lettuce harvested from Salinas, California, such as whole heads of romaine, hearts of romaine, and packages of precut lettuce and salad mixes which contain romaine, including baby romaine, spring mix, and Caesar salad.
    • Restaurants and retailers should check the label on bags or boxes of romaine lettuce, or ask their suppliers about the source of their romaine lettuce.
    • Suppliers, distributors, and others in the supply chain should not ship or sell romaine harvested in Salinas, California.
  • If you have romaine lettuce at home:
    • If the packaging has “Salinas” on the label in any form (whether alone or with the name of another location), don’t eat it, and throw it away.
    • If it isn’t labeled with a growing region, don’t eat it, and throw it away.
    • If you don’t know if the lettuce is romaine or whether a salad mix contains romaine, don’t eat it, and throw it away.
    • Wash and sanitize drawers or shelves in refrigerators where romaine lettuce was stored. Follow these five steps to clean your refrigerator.
  • If you are buying romaine lettuce at a store:
    • If the packaging has “Salinas” on the label in any form (whether alone or with the name of another location), don’t buy it.
    • If it isn’t labeled with a growing region, don’t buy it.
    • If the packaging has “Salinas” on the label in any form (whether alone or with the name of another location), don’t sell or serve it.
    • If it isn’t labeled with a growing region, don’t sell or serve it.
  • About Shiga toxin-producing E. coli (STEC):
    • People with STEC usually get sick with bloody diarrhea and stomach cramps three to four days after eating food contaminated with the germ. Contact your doctor if you think you ate romaine lettuce from the Salinas region of California and are having any symptoms.
    • Remember to wash your fresh fruits and vegetables before eating them, even if they have been “pre-washed.”
  • Additional information can be found on the following websites:

  • The Wisconsin Department of Health Services (DHS) is working with the Buffalo County Health Department, the Department of Agriculture, Trade, and Consumer Protection (DATCP), and the CDC (Centers for Disease Control and Prevention) regarding a confirmed case of hepatitis A virus infection in a food handler.
    • A food handler with hepatitis A infection is concerning because of the potential for food contamination.
    • This individual worked at the Mondovi Hansen’s IGA store deli while they were able to spread Hepatitis A, from October 28 through November 17, 2019.
    • Health officials are advising people who shopped at the Mondovi Hansen’s IGA during October 28 and November 17, 2019 and ate produce or deli items to call their doctor. They should ask about their risk of exposure to hepatitis A virus and options for vaccination (if not already vaccinated).
    • There is no risk of exposure outside of these dates.
  • Symptoms of hepatitis A infection can include abdominal pain, nausea, vomiting, diarrhea, dark urine, clay-colored stool, fever, chills, and yellow skin and eyes (jaundice).
    • Hepatitis A symptoms occur between 15 and 50 days after exposure and can last for several weeks to months. Most people recover from hepatitis A on their own, but occasionally patients may need to be hospitalized. Hepatitis A is rarely fatal.
    • Antibiotics do not work against hepatitis A virus.
  • The best ways to prevent the spread of hepatitis A virus are:
    • Get the hepatitis A vaccine. A single shot of the hepatitis A vaccine can help prevent an infection if given within two weeks of being exposed to hepatitis A virus.
    • Always wash your hands with soap and water after using the bathroom or changing a diaper. Hand sanitizer is NOT effective against Hepatitis A virus.
    • Thoroughly wash your hands with soap and water before and during food preparation and before eating food.
  • Additional information can be found at the following websites:

  • The Wisconsin Department of Health Services (DHS) is working with local health departments, CDC (Centers for Disease Control and Prevention), and the U.S. Food and Drug Administration (FDA) to investigate a multistate outbreak of hepatitis A that may be linked to fresh, non-organic blackberries. These blackberries were sold at Fresh Thyme Farmers Market and Woodman's Market stores during September 9 through September 30, 2019.
  • A single, common supplier of these berries has not been identified and no recall has been issued at this time.
    • Ill patients reported eating fresh, non-organic blackberries from Fresh Thyme Farmers Market or Woodman's Market stores in Indiana, Michigan, Minnesota, Missouri, Nebraska, and Wisconsin.
    • As of December 11, 2019, the CDC reports that 18 people in six states are infected with the outbreak strains of hepatitis A.
    • Wisconsin has five confirmed cases linked to this outbreak. Three cases in Wisconsin have been hospitalized.
    • Ill patients reported their illnesses starting between October 15 and November 5, 2019.
  • If you purchased any blackberries from a Fresh Thyme or Woodman's location between September 9 and September 30, 2019, do not eat them and throw them away.
    • Check your freezer for these blackberries. If you froze them to eat later, do not eat them and throw them away.
    • If you ate any of these blackberries within the last two weeks and are not vaccinated against hepatitis A, contact your doctor or local health department to discuss vaccination options.
  • Symptoms of hepatitis A infection can include abdominal pain, nausea, vomiting, diarrhea, dark urine, clay-colored stool, fever, chills, and yellow skin and eyes (jaundice).
    • Hepatitis A symptoms occur between 15 and 50 days after exposure and can last for several weeks to months. Most people recover from hepatitis A on their own, but occasionally patients may need to be hospitalized. Hepatitis A is rarely fatal.
    • Antibiotics do not work against hepatitis A virus.
  • Additional information can be found on the following websites:

Fresh, paper-thin sliced raw beef
  • The Wisconsin Department of Health Services (DHS), in collaboration with the La Crosse County Health Department, investigated an outbreak of salmonellosis associated with consuming beef tartare served at Restore Public House in La Crosse between July 10 and July 12, 2019.
  • 35 restaurant patrons were interviewed during the investigation. Seven confirmed and 10 probable (ill but not tested) cases were linked to this outbreak.
  • Restore Public House voluntarily removed the beef tartare dish from their menu once they were notified of the illnesses.
  • See the DHS salmonellosis fact sheet (PDF) for more information on common symptoms of salmonellosis. If you have any symptoms of salmonellosis, please contact your doctor.
  • Consumption of raw or undercooked meat, poultry, or eggs can increase your risk of foodborne illness. See the DHS food safety webpage for more information on safe food practices.
  • Additional information can be found on the following websites:

Dried pig ears.
  • The Wisconsin Department of Health Services (DHS) and local health departments worked with the CDC (Centers for Disease Control and Prevention) and the U.S. Food and Drug Administration (FDA) to investigate a multistate outbreak of salmonellosis linked to contact with pig ear dog treats.
    • 154 people in 34 states were infected with the outbreak strains of Salmonella.
    • 35 people were hospitalized, with no deaths reported. Children younger than 5 years accounted for 19% of illnesses.
    • In Wisconsin, four laboratory-confirmed cases were linked to this outbreak.
  • CDC and FDA have dropped their warning to avoid buying or feeding any pig ear treats, except for treats that have been recalled. Consumers should not give recalled pig ears to their pets. Consumers should always wash their hands right after feeding any pig ear treats to their dogs.
    • Several companies recalled pig ear products because they might have been contaminated with Salmonella. No single supplier, distributor, or common brand of pig ear treats has been identified that could account for all the illnesses.
    • Details on pig ear products involved with the outbreak can be found on the FDA webpage.
  • See the DHS salmonellosis fact sheet, P-42088 (PDF) for more information on common symptoms and treatment of salmonellosis. If you have any symptoms of salmonellosis, please contact your doctor.
  • Additional information can be found on the following websites:

  • The Wisconsin Department of Health Services (DHS) and local health departments investigated an outbreak of salmonellosis linked to consuming food from Outpost Natural Food locations.
  • On August 23, 2019, the Wisconsin Department of Agriculture, Trade and Consumer Protection (DATCP) and the City of Milwaukee Health Department suspended meat and food processing at Outpost Natural Foods located in Milwaukee at 2826 S. Kinnickinnic Ave. due to insanitary conditions. DATCP suspended the cooperative's meat establishment license and the City of Milwaukee suspended the cooperative's retail food processing activities.
  • Insanitary conditions were discovered during a routine inspection and ready-to-eat products tested positive for Salmonella.
  • Four people infected with the outbreak strains of Salmonella found at Outpost Natural Foods; three were available for interview and each reported consuming food from one of the Outpost Natural Food locations.
  • Known patient onset dates ranged from March 20-May 6, 2019.
  • All licenses have been re-instated and Outpost Natural Food is operating under Voluntary Compliance Agreement’s on each license.

Chickens feeding on the grass in the backyard

Store bought vegetable tray
  • The Department of Health Services (DHS), the Wisconsin Department of Agriculture, Trade, and Consumer Protection (DATCP), Minnesota Department of Health and local health departments worked with the CDC (Centers for Disease Control and Prevention), and the U.S. Food and Drug Administration (FDA) to investigate a multi-state outbreak of salmonellosis linked to consumption of certain Del Monte vegetable trays.
  • All ill patients associated with this outbreak, four in Wisconsin and one in Minnesota, reported eating a Del Monte vegetable tray purchased from a Wisconsin or Minnesota Kwik Trip location before they became ill.
  • The Del Monte vegetable trays associated with the investigation contain broccoli, cauliflower, carrots, and dill dip. It is not likely that the trays that made people sick are still on the market or still in people’s homes.
  • See the DHS salmonellosis fact sheet, P-42088, for more information on common symptoms and treatment of salmonellosis.
  • Additional information can be found on the following websites:

Fresh melon cut up on a plate
  • The Wisconsin Department of Health Services (DHS) in collaboration with the Wisconsin Department of Agriculture, Trade and Consumer Protection (DATCP), the CDC (Centers for Disease Control and Prevention), and the U.S. Food and Drug Administration (FDA) alerted Wisconsin consumers to a multistate outbreak of Salmonella Carrau infections linked to eating pre-cut melons sold by Caito Foods LLC.
  • One case was reported in Wisconsin and 137 people infected with the Salmonella strain were reported in nine other states.
  • On April 12, 2019, Caito Foods LLC recalled pre-cut watermelon, honeydew melon, cantaloupe, and pre-cut fruit medley products containing one of these melons supplied at the Caito Foods LLC facility in Indianapolis, Indiana.
  • Additional information can be found on the following websites:

Raw ground beef.
  • The Wisconsin Department of Health Services (DHS) and local health departments investigated four cases of salmonellosis affecting Wisconsin residents with the same strain (DNA fingerprint) of Salmonella.
  • All four of the Wisconsin patients were linked to Butterball raw ground turkey. Testing of leftover raw ground turkey received by the patients was positive for the outbreak strain of Salmonella.
  • These items were shipped to institutional and retail locations nationwide. The affected ground turkey product may have been distributed through food pantries.
  • As a result of this outbreak, Butterball recalled 78,164 pounds of raw ground turkey products. A complete list of products included in the recall can be found in the U.S. Department of Agriculture Recall notice. The products subject to recall bear establishment number “EST. P-7345” inside the USDA mark of inspection.
  • Additional information can be found on the following websites:

2018 Outbreaks

Close-up of the front of a running shower head
  • The Wisconsin Department of Health Services (DHS), in collaboration with the CDC (Centers for Disease Control and Prevention), and Public Health Madison and Dane County, worked closely with UW Health on the investigation of nosocomial Legionnaires’ disease associated with the University Hospital in Madison, Wisconsin.
  • On Nov. 28, 2018, DHS was notified by a UW Health Infection Preventionist of confirmed cases of Legionnaires’ disease among patients admitted to their hospital since Oct. 31, 2018.
  • 14 cases of Legionnaires' disease were identified at University Hospital. Three patients who had been hospitalized for other serious health conditions died.
  • An environmental investigation at the hospital was completed.
  • Legionellosis in an infection caused by Legionella bacteria. There are two different types of legionellosis: Pontiac fever and Legionnaires' disease. Pontiac fever is a mild respiratory illness and Legionnaires' disease is a type of pneumonia.
    • Legionnaires' disease is not normally spread from person to person.
    • This CDC infographic outlines how Legionella bacteria is spread from water sources to people.
  • Additional information can be found on the following websites:

Bowl of dry breakfast cereal

Bowl of salad lettuces

Fresh melon cut up on a plate
  • The Wisconsin Department of Health Services (DHS) and the Wisconsin Department of Agriculture, Trade and Consumer Protection (DATCP) alerted Wisconsin consumers to a multistate outbreak of Salmonella Adelaide infections linked to the consumption of pre-cut melons. No cases were identified in Wisconsin residents, but the recalled products were sold at locations in the state.
  • The Food and Drug Administration (FDA) identified Costco stores in the following Wisconsin cities as having distributed the recalled pre-cut melon: Bellevue (Green Bay), Grafton, Grand Chute, Menomonee Falls, Middleton, New Berlin, Pewaukee, Pleasant Prairie, and Sun Prairie.
  • The full list of stores where this product was distributed is available on the FDA’s website.
  • No cases were reported in Wisconsin. Nationally, 77 people infected with the Salmonella strain have been reported.
  • Additional information can be found on the following websites:

  • Case counts in Wisconsin can be found on our synthetic cannabinoid webpage.
  • The CDC (Centers for Disease Control and Prevention) investigated this outbreak across the nation.
  • If you have used any of these products, and start experiencing severe, unexplained bleeding or bruising, please have someone take you to the hospital immediately or call 911.

Digital illustration of a neuron
  • The Wisconsin Department of Health Services (DHS) and local health departments (LHDs) are actively working to identify potential cases of acute flaccid myelitis (AFM). DHS is working with health care providers and the CDC (Centers for Disease Control and Prevention) during this developing situation.
  • There were nine confirmed and three probable cases of AFM in Wisconsin.
    • AFM is also called “acute flaccid paralysis with anterior myelitis” or “polio-like syndrome.” It is rare and mainly found in children. It affects the body’s nervous system, specifically the spinal cord. AFM can be caused by some viruses, environmental toxins, and genetic disorders.
    • Viruses that can cause AFM include enteroviruses (polio and non-polio) and flaviviruses, such as West Nile Virus, Japanese Encephalitis virus, or St. Louis encephalitis virus. Other viruses that may cause AFM are herpesviruses (e.g., cytomegalovirus, Epstein-Barr virus) and adenoviruses.
  • See the DHS AFM webpage for more information on common symptoms and treatment of AFM. Seek medical care as soon as possible if you notice any symptoms of AFM in you or your child, for example if your child is not using their arm or leg normally.
  • Additional information can be found on the following websites:
    • AFM Fact Sheet, P-01298 (Multiple Languages): Educational fact sheet for the general public on AFM covering signs and symptoms, treatment, and prevention.
    • About AFM: CDC webpage including information on symptoms, diagnosis, possible causes of AFM, treatment, and prevention.

Romaine Lettuce on white background
  • The Wisconsin Department of Health Services (DHS), CDC (Centers for Disease Control and Prevention), U.S. Food and Drug Administration (FDA), and numerous other states investigated a multistate outbreak of E. coli O157:H7 infections.
  • This outbreak was not related to the multistate outbreak of E. coli O157:H7 infections linked to romaine lettuce that occurred earlier in 2018 (see below for Wisconsin-specific information).
  • Nationwide, 62 people from 16 states were infected with the outbreak strain of E. coli O157:H7. Illnesses started on dates ranging from Oct. 7 to Dec. 4, 2018.
  • There were 25 people hospitalized, with no deaths reported. One Wisconsin E. coli O157:H7 infection was linked to the outbreak.
  • This outbreak appears to be over as of January 9, 2019.
    • Contaminated lettuce that made people sick in this outbreak should no longer be available.
    • Epidemiologic, laboratory, and traceback evidence from the United States and Canada indicated that romaine lettuce harvested from the Central Coastal growing regions of northern and central California was the likely source of the outbreak.
  • Additional information on the following websites:

  • The Wisconsin Department of Health Services (DHS) is working with the Wisconsin Department of Agriculture, Trade, and Consumer Protection (DATCP) to investigate bovine tuberculosis (TB) in a dairy herd located in Dane County. The Wisconsin TB Program is working with Public Health Madison and Dane County to complete a contact investigation on the farm and identify individuals who may need TB testing.
  • Precautions are being taken by DATCP and the farm to ensure the safety of both meat and milk. Consumers and the general public are not at risk of contracting TB infection from this herd. Food safety laws prevent meat from infected animals from entering the food chain and the pasteurization process destroys disease-causing organisms in milk.
  • People are not at risk if they have made only brief visits to the affected farm, have not consumed raw milk, or have not worked closely for extended periods of time with animals. Visiting the farm, living near the farm, or making deliveries to the farm does not pose a risk for becoming infected with bovine TB.
  • Additional information on bovine TB can be found on the following websites:

Store bought vegetable tray
  • The Department of Health Services (DHS), the Wisconsin Department of Agriculture, Trade, and Consumer Protection (DATCP), and local health departments are working with the CDC (Centers for Disease Control and Prevention) and the U.S. Food and Drug Administration (FDA) to investigate an outbreak of cyclosporiasis linked to the consumption of Del Monte vegetable trays sold at Kwik Trip.
    • 177 cases report consuming a Del Monte vegetable tray purchased at a Kwik Trip location in Wisconsin. Most ill persons reported purchasing the tray on or after May 16, 2018. Kwik Trip voluntarily removed the trays from sale in their stores on June 8, 2018.
    • Consumers should not eat 6 oz. or 12 oz. Del Monte vegetable trays (containing broccoli, cauliflower, carrots, and dill dip) purchased at a Kwik Trip location.
    • Del Monte issued a recall of 6 oz, 12 oz, and 24 oz vegetable trays with dip. See the FDA website for full details.
  • As of Sept. 5, 2018, CDC was notified of 250 laboratory-confirmed cases of Cyclospora infection in people from four states who reported consuming pre-packaged Del Monte Fresh Produce vegetable trays containing broccoli, cauliflower, carrots, and dill dip.
  • Based on epidemiological data or traceback evidence, it was not possible to determine if an individual component of the vegetable trays was the likely vehicle of infection. Read the related statement from the FDA for additional information.
  • See the DHS cyclosporiasis fact sheet, P-42041 (PDF) for more information on common symptoms and treatment of cyclosporiasis. If you have any symptoms of cyclosporiasis, please contact your doctor.
  • Additional information can be found on the following websites:

Chickens feeding on the grass in the backyard
  • During 2018, the Wisconsin Department of Health Services (DHS) and local health departments worked with the CDC (Centers for Disease Control and Prevention) to investigate multistate outbreaks of Salmonella infections linked to contact with backyard poultry.
    • The CDC reported that 334 people from 47 states became ill with a strain of Salmonella linked to backyard poultry during 2018.
    • In Wisconsin, 33 laboratory-confirmed cases of Salmonella were linked to the 2018 national backyard poultry outbreak.
    • Nationally, illness onset dates ranged from Feb. 15 to Aug. 10, 2018. Children younger than 5 years accounted for 21% of illnesses.
  • Outbreaks of Salmonella infections linked to contact with backyard poultry happen every year in the U.S. Many of these infections are preventable.
  • More information about outbreaks associated with live poultry can be found at CDC's webpage U.S. Outbreaks of Zoonotic Diseases Spread between Animals and People.
  • More information about backyard poultry and safe handling can be found at the DHS backyard poultry webpage.

  • The Wisconsin Department of Health Services (DHS), the CDC (Centers for Disease Control and Prevention), U.S. Food and Drug Administration (FDA), and numerous other states investigated a multistate outbreak of E. coli O157:H7 infections.
  • Epidemiologic, laboratory, and traceback evidence indicated that romaine lettuce from the Yuma growing region was the likely source of this outbreak.
  • Nationwide, 210 people from 36 states were infected with the outbreak strain of E. coli O157:H7. Illnesses started on dates ranging from March 13, 2018, to May 12, 2018.
  • As of 6/28/2018, 96 people were hospitalized, with five deaths reported. Three Wisconsin E. coli O157:H7 infections have been linked to the outbreak.

2017 Outbreaks

Close-up of the front of a running shower head
  • The Wisconsin Department of Health Services (DHS), in collaboration with the Sauk County Health Department, and the Wisconsin Department of Agriculture, Trade, and Consumer Protection (DATCP), worked with Christmas Mountain Village on the investigation of three cases of Legionnaires’ disease associated with Christmas Mountain Village Resort in Wisconsin Dells, Wisconsin.
  • Legionnaires’ disease is a type of pneumonia caused by the bacteria Legionella, which can grow inside building water systems (pipes, hot water heaters, etc.).
    • Symptoms of Legionnaires’ disease can include cough, fever, chills, muscle aches, headache, and shortness of breath.
    • Legionnaires’ disease is more common in people aged 50 years and older, those who smoke, and among individuals who are at higher risk of infection, such as those with a chronic illness, respiratory disease, or a weakened immune system.
    • Legionnaires' disease is not normally spread from person to person.
    • People can get Legionnaires’ disease after breathing in small water droplets with Legionella. This CDC (Centers for Disease Control and Prevention) infographic outlines how Legionella bacteria is spread from water sources to people.
  • Christmas Mountain Village Resort is working with a water management company on testing the resort’s water for Legionella and remediation (removal of Legionella from the water system).
    • The resort is continuing to notify guests at the time of reservation and check-in.
    • Point-of-use filters have been installed on showerheads and faucets in all units of the resort. These point-of-use filters are a recommended risk-reduction measure and will stay in place until testing and completing remediation (removal of Legionella) of all units at the resort is complete.
  • People who are planning to visit Christmas Mountain Village should evaluate their risk of infection or talk to their doctor before their visit and may wish to consider postponing their visit until after remediation is complete.
  • DHS and the Sauk County Health Department continue to monitor for new cases potentially associated with the resort. People who become ill with symptoms of Legionnaires’ disease within 14 days of their stay should seek medical attention and mention the information above to their doctor.
  • Additional information can be found on the following websites:

Three rats, one is white, other is dark gray and last one is light gray
  • During 2017, the Wisconsin Department of Health Services (DHS), Wisconsin local health departments, the CDC (Centers for Disease Control and Prevention), and other state health departments investigated an outbreak of illnesses caused by the Seoul virus, a rare type of hantavirus carried by Norway and black rats.
  • The outbreak was detected in January 2017 when two Wisconsin residents were diagnosed with Seoul hantavirus (SHV), which can cause hemorrhagic fever with renal syndrome. Norway and black rats are the only known reservoir. The investigation determined the affected individuals were in routine contact with pet rats, either owning rats as pets or operating a rattery where they regularly sold and exchanged rats with individuals and other ratteries.
  • The response efforts included tracking movement of rats between locations (ratteries, pet homes) with infected rats, coordination of hantavirus testing for rats linked to the outbreak, and follow-up with people exposed to infected rats or ratteries.
  • Nationwide, 17 laboratory-confirmed recent human cases of SHV infection were reported as part of this outbreak, including three cases in Wisconsin. Two additional Wisconsin residents were identified with evidence of past infection.
    • The outbreak investigation led to the identification of 31 infected ratteries in 11 states and Canada. This indicated that Seoul virus should be considered endemic in the U.S., and that pet rats in the U.S., including Wisconsin, can be carrying Seoul virus at any time.
    • Rat owners and breeders may wish to determine if a rat is infected prior to introducing it into their home or rattery. Commercial testing for Seoul virus is available through several laboratories. Contact your veterinarian for testing information.
  • See the DHS hantavirus fact sheet, P-42053 for more information on common symptoms and prevention of SHV. If you have any symptoms of SHV and a history of rat contact, please contact your doctor.
  • Additional information can be found on the following websites:

2016 Outbreaks

Sleepy puppy rests in his owner's arm
  • The Wisconsin Department of Health Services (DHS), the CDC (Centers for Disease Control and Prevention), several other states, and the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service (USDA-APHIS) investigated a multistate outbreak of multidrug-resistant (MDR) Campylobacter infections.
  • Nationwide, 113 people from 17 states were infected with the outbreak strain of MDR Campylobacter, including eight people in Wisconsin. Illnesses started on dates ranging from Jan. 12, 2016, to Jan. 7, 2018.
    • Of the 103 ill people with information available, 23 (22%) were hospitalized.
    • This outbreak was linked to contact with pet store puppies. Of those who became ill, 90% had a link to puppies at, or from, a Petland store, or had contact with with a person who became sick after contact with a puppy from a Petland store.
  • In Wisconsin, eight people became sick and two were hospitalized.
  • All puppies and dogs can carry Campylobacter bacteria. Because of this, it is especially important to wash your hands thoroughly with running water and soap for at least 20 seconds every time you touch dogs, their poop, or their food. Adults should supervise handwashing for young children. Please see our Handwashing After Animal Contact flyer, P-01699 for more information about how to prevent these infections.
  • See the DHS campylobacteriosis fact sheet, P-42045 for more information on common symptoms and treatment of campylobacteriosis. If you have any symptoms of campylobacteriosis, please contact your doctor.
  • Additional information can be found on the following websites:

Elizabethkingia Anophelis - culture plate
  • The Wisconsin Department of Health Services (DHS) and the CDC (Centers for Disease Control and Prevention) investigated an outbreak of bacterial infections caused by Elizabethkingia anophelis.
  • There were 67 total cases reported to DHS during this outbreak. Of those cases, 63 were confirmed, and four tested positive for Elizabethkingia but will never be confirmed as the same strain of Elizabethkingia anophelis because the specimens were not available for testing.
  • The majority of patients who acquired these infections were over 65 and all patients had a history of at least one underlying serious illness.
  • Counties with confirmed cases include Columbia, Dane, Dodge, Fond du Lac, Jefferson, Milwaukee, Ozaukee, Racine, Sheboygan, Washington, Waukesha, and Winnebago.
  • There were 18 deaths among individuals with confirmed Elizabethkingia anophelis infections and an additional one death among possible cases for a total of 19 deaths. It was not determined if these deaths were caused by the infection or other serious, pre-existing health problems. Counties where deaths occurred are: Columbia, Dodge, Fond du Lac, Milwaukee, Ozaukee, Racine, Sheboygan, Washington, and Waukesha.
  • DHS quickly identified effective antibiotic treatment for Elizabethkingia, and alerted health care providers, infection preventionists, and laboratories statewide. Initial guidance was sent on January 15, 2016, and there was a rapid identification of cases and health care providers were able to treat and improve outcomes for patients.
  • Additional information can be found on the following websites:

2015 Outbreaks

Contented calf laying on straw
  • The Wisconsin Department of Health Services, along with the CDC (Centers for Disease Control and Prevention), U.S. Department of Agriculture, Wisconsin State Laboratory of Hygiene, Wisconsin Veterinary Diagnostic Laboratory, and Wisconsin Department of Agriculture, Trade and Consumer Protection and other state health departments, investigated an outbreak of multidrug-resistant Salmonella Heidelberg infections associated with contact with dairy bull calves.
  • Nationwide, 56 people from 15 states were infected with the outbreak strain of Salmonella Heidelberg.
    • Illnesses occurred during Jan. 27, 2015, to Nov. 25, 2017. Thirty-five percent of people were hospitalized, and no deaths were reported.
    • Contact with dairy calves or cattle was reported by 63% of people who became sick.
  • In Wisconsin, 18 people were infected with this outbreak strain.
  • See the CDC Salmonella Heidelberg website for complete outbreak details.
  • Please see our Staying Healthy While Working on a Farm, P-01711 and Handwashing After Animal Contact, P-01699 flyers for important information on staying healthy after contact with animals.
  • Additional information can be found on the following websites:
Last revised January 22, 2024