Skip to main content

Outbreaks, Recalls, and Investigations

Following is a list of selected outbreaks, recalls, and investigations with wide impact in Wisconsin.

The Wisconsin Department of Health Services (DHS) is working with local, state, and federal partners to investigate a multistate outbreak of Salmonella linked to backyard poultry.

  • According to the Centers for Disease Control and Prevention (CDC), 184 people in 31 states have become sick with the outbreak strain of Salmonella. Fifty-three people have become hospitalized and one death has occurred.
  • Wisconsin has 17 laboratory confirmed cases linked to this outbreak.

Backyard poultry and Salmonella

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 use 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 in their mouths.

What you should do

If you own or have contact with poultry, take these steps to reduce the risk of becoming ill with Salmonella infection:

  • Always wash your hands after touching backyard poultry, their eggs, or anything within the areas in which they live or roam. Use hand sanitizer if soap and water are not available.
  • Don't kiss or snuggle backyard poultry, and don't eat or drink around them.
  • Keep poultry, even when they are babies, outside your house.
  • Supervise kids around flocks and don't let children younger than 5 years old touch chicks, ducklings, or other backyard poultry.
  • Handle eggs safely.
  • Call your health care provider right away if you have any of these severe symptoms:
    • Diarrhea and a fever higher than 102°F
    • Diarrhea for more than three 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

What stores selling backyard poultry should do

Symptoms of Salmonella

  • Diarrhea, fever, and stomach cramps are the most common symptoms of Salmonella.
    • Symptoms usually start six hours to six days after swallowing the germ.
    • Most people recover in four to seven days, without treatment.
    • Some groups, like children younger than 5 years, adults 65 years and older, and people with weakened immune systems, may experience more severe illnesses and that require medical treatment and hospitalization.

Resources

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

The Centers for Disease Control and Prevention (CDC), public health officials in several states, the California Department of Public Health Infant Botulism Treatment and Prevention Program, and the U.S. Food and Drug Administration, are investigating a multistate outbreak of infant botulism linked to infant formula.

According to the CDC as of December 10, 2025, this outbreak includes 51 infants with suspected or confirmed botulism in 19 states. All 51 infants were hospitalized, and no deaths have been reported. This outbreak investigation now includes 10 additional cases that occurred from December 2023 through July 2025.

The Wisconsin Department of Health Services has identified and is investigating a case of infant botulism related to this outbreak. The infant has been discharged from the hospital after receiving treatment and is recovering.

Recalled infant formula

The recall includes all lot numbers, sizes of cans and single serve sticks of ByHeart Whole Nutrition infant formula. Parents and caregivers should stop using all ByHeart Whole Nutrition infant formula immediately.

Advice to consumers

  • Do not use any ByHeart Nutrition infant formula.
    • If anyone has leftover ByHeart powdered formula that was fed to their infant, they should record the lot number and best by date, and keep it stored for at least a month. If an infant fed ByHeart powdered formula develops symptoms of infant botulism, Bureau of Communicable Disease (BCD) staff may want to collect it for testing.
  • Wash items and surfaces that may have touched the recalled formula using hot soapy water or a dishwasher.

When to see a health care provider

Parents should take their infant to see a health care provider when both of the following apply:

  • Your infant has consumed ByHeart Whole Nutrition infant formula.
  • Your infant has symptoms of infant botulism. Symptoms of infant botulism can take weeks to develop and include:
    • Poor feeding.
    • Loss of head control.
    • Difficulty swallowing.
    • Decreased facial expression.

Public hotline for questions related to infant botulism

The California Department of Public Health has a hotline for parents and caregivers to get answers to questions they have about infant botulism. The hotline is open seven days a week from 9 a.m. to 10 p.m. Central Daylight Time. You can reach the hotline at 833-398-2022.

Frequently asked questions for parents

If my infant has consumed the recalled formula, can I test my baby to know if they have botulism?

There is no test to determine if an infant without symptoms has been exposed to the bacteria. Only infants that have symptoms of botulism and are hospitalized can be tested. The special test is done through a stool sample.

If my infant has consumed ByHeart Whole Nutrition infant formula, will they get botulism?

Not all infants who consumed the recalled formula will develop botulism. The presence of the bacteria alone doesn't cause botulism. Once the bacteria have started growing in the gut, they produce a toxin that affects the nervous system. The toxin is what causes symptoms of botulism. Younger babies are more likely to have less mature gut microbiomes and are more susceptible to getting sick with botulism.

What symptoms should I watch for?

The first symptom is usually constipation followed by droopy eyelids, poor sucking, pooling of milk in mouth, a weak or gargled cry, and “floppy” neck. Having a fever is not a symptom of botulism.

How is botulism treated?

To prevent worsening symptoms, babies suspected of having botulism are often given an antitoxin called BabyBIG. Infants with botulism need to be hospitalized. Supportive treatment will take several weeks and a feeding tube and ventilation may be required. Physical and occupational therapies are needed for full recovery. Most babies that receive supportive care will survive and recover.

Advice to businesses

  • Do not sell or use recalled ByHeart Whole Nutrition infant formula.
  • Sanitize surfaces that may have come in contact with recalled formula.

Advice to clinicians

Frequently asked questions for health care providers

When to test for infant botulism?

  • Testing for infant botulism is only done if an IBTPP consult determines the infant meets clinical case criteria and will receive BabyBIG.
  • There are no screening tests to determine if an infant without symptoms has been exposed to botulinum neurotoxin (BoNT).
  • Testing for BoNT requires approval from BCD and the referral testing laboratory.
  • Administration of BabyBIG is not dependent on BoNT test results, so testing is not the first priority.
  • A stool specimen is collected from symptomatic infants for BoNT testing and Clostridium culture. Instructions for specimen collection and handling are provided at time of BCD approval.
  • The gold standard confirmatory test for BoNT is the mouse bioassay which can take up to two weeks to finalize results.

When to suspect a patient has botulism?

  • Suspect botulism in infants who develop clinically-compatible signs and symptoms of botulism and have consumed ByHeart Whole Nutrition infant formula within the past month.
  • Consult with the IBTPP for an infant suspected of having botulism. Consult is usually initiated by the attending pediatrician after initial medical assessment.
  • Suspected cases of botulism should be reported to BCD immediately at 608-267-9003, or after hours at 800-943-0003 (option 4). BCD can arrange consult with IBTPP and facilitates testing of clinical specimens and environmental samples.

Resources

Visit the FDA and CDC webpages for more information on this outbreak, and to stay up to date on other foodborne outbreaks and recalls:
CDC: Infant Botulism Outbreak Linked to Infant Formula, November 2025
CDC: About Botulism
DHS: Botulism
FDA: Outbreak Investigation of Infant Botulism-Infant Formula

California Department of Public Health Infant Botulism Hotline

To view previous outbreaks and investigations, visit our Past Outbreaks in Wisconsin page.

Related pages

Glossary

 
Last revised May 15, 2026