Infant botulism

What is infant botulism?

Infant botulism happens when a baby swallows germ spores. The spores grow in the gut and make a poison that weakens the muscles. It is a medical emergency.

The germs are found in many places in nature. Some foods, like honey, can carry them. It is rare for them to make people sick.

It mostly affects babies between 6 weeks and 6 months old. It can happen as early as 6 days or as late as 1 year.

CDC says it does not know why some babies get sick from the spores, and that most cases cannot be prevented. It does say not to give honey to a child under 1 year old.

CDC says the germs can be found in soil and dust, and even inside homes after cleaning. California’s state infant botulism program says that in most cases no source is found. It says most sick babies likely swallowed spores stuck to tiny bits of dust in the air.

What are the signs of infant botulism, and when should I see a doctor?

Early signs are often constipation and poor feeding. A baby may have drooping eyelids, a weak cry and less expression in the face. If you see these signs, see your doctor or go to the emergency room right away.

Pupils that are slow to react to light can be another sign. CDC says not to wait. MedlinePlus says to go to the emergency room or call 911 right away if your baby has symptoms.

CDC says signs usually show up within 30 days after a baby swallows the spores.

How do doctors diagnose infant botulism?

Doctors first make the diagnosis from the baby’s signs. A stool test done by a state public health lab can confirm it. In the ByHeart outbreak, CDC also counted some babies with negative or unclear tests as probable cases.

On exam, a doctor may find weak, floppy muscles, a weak gag reflex and drooping eyelids.

For counting cases, public health calls a case confirmed when a baby under 1 has signs that fit and a lab finds the poison or the germ.

Our ByHeart treatment page explains more about testing and care in the hospital.

Which records show an infant botulism diagnosis?

The hospital chart shows the baby’s signs and the doctor’s diagnosis. The state lab report shows whether the stool test found the poison or the germ. The state health department also gets a report on each case.

CDC says almost all known cases in the U.S. are recorded, and cases confirmed by a lab are reported to CDC.

In the ByHeart outbreak, health officials reviewed the babies’ medical records. A case counted as confirmed if the baby had the formula and a positive lab test. It counted as probable if the baby had the formula, the test was negative or unclear, the illness fit and no other cause was found.

Parents can ask the hospital for copies of the chart and test results. HHS says the hospital normally has up to 30 days to give you a copy. It cannot refuse because a bill is unpaid.

What does research say about ByHeart formula and infant botulism?

CDC said lab tests and case data showed that ByHeart formula had the germ and made babies sick. There were 48 cases in 17 states. Lab tests confirmed 28, and 20 were probable. None of the babies died.

In March 2026, CDC said: “Epidemiologic and laboratory data showed that ByHeart Whole Nutrition infant formula was contaminated with C. botulinum and made infants sick.” CDC has said the outbreak is over.

FDA found the germ in a powdered milk ingredient. As of August 2026, FDA was still looking for the root cause.

In August 2026, FDA looked at a second, smaller outbreak: 4 babies who drank Nara Organics formula. It said DNA test results and shared milk suppliers point to a common source of contamination for both outbreaks. FDA has not yet found the root cause.

These agency findings are about the outbreak as a whole. We found no court ruling that ByHeart formula caused any one baby’s illness.

Who brings infant botulism claims in the ByHeart cases?

Families say their babies got very sick with infant botulism from ByHeart formula that had the germ in it. Other cases are about what people paid for the formula. Each family’s own facts decide whether it has a claim.

In April 2026, the federal cases were grouped before Judge Arun S. Subramanian in New York. The panel that grouped them said the cases share questions of fact.

As of early October 2026, the court’s orders dealt with schedules and other early steps. None had ruled on whether the formula caused the illnesses. The next court meeting is set for December 16, 2026.

CDC’s count of outbreak cases and the lawsuits are separate. We did not confirm whether any family in the lawsuits is one of CDC’s 48 cases.

Can a parent get a baby’s infant botulism records?

Usually, yes. HHS says a parent is normally the one who can use a minor child’s rights to health records. It names a few exceptions where a parent does not have that role.

When a baby has died, the person who runs the estate, called the executor or administrator, may get the records that job requires. Doctors may also share some facts with a family member who was involved in the baby’s health care or in paying for it. They can share only what relates to that role. State law sets who can act in each role.

If your baby has died, the wrongful death case page explains in general how those claims work.