Infant Botulism Outbreak

By: Natalie Samara

Edited: Ritisha Debnath

According to Cleveland Clinic, infant botulism is a rare but serious illness that affects babies under one year old. Clostridium botulinum, a gram-positive, rod-shaped, bacterium, has the ability to produce botulinum toxin in the formula. The symptoms usually start with:

• Choking when trying to feed

• Constipation

• Poor feeding

• Eyelid drooping (ptosis)

• Lack of facial expressions, being unable to lift their head, or other signs of muscle weakness or paralysis

• Weaker crying

• Weakness or decreased muscle tone, especially starting at the top of their body and limbs, making your baby feel “floppy” and keeping them from reaching or grabbing

• Bowel movement changes, like not pooping for days or even weeks at a time

If left untreated, infant botulism can weaken muscles used in breathing. This can lead to breathing problems and require weeks of hospitalization. All infants with suspected botulism should be treated with BabyBIG, a medication used to treat infant botulism. Babies get botulism if they eat something containing spores from the bacteria Clostridium botulinum. The bacteria changes to a spore form to survive harsh environments. Inside the baby’s digestive system, the spores return to their bacterial form, multiply and start making a toxin, then enters the bloodstream and eventually disrupts their nervous system.

The best-known way that babies can get Clostridium botulinum spores in their gut is from honey and that’s why you should never give honey to babies under a year old. Everyone has healthy bacteria that live in their digestive tract (gut microbiome). In those over one year old, healthy bacteria usually keeps botulism-causing bacteria from staying long enough to make the toxin, but the infant’s gut microbiomes can’t always do that.

Botulism-causing bacteria can live inside those over a year old and make the toxin spread from the inside of the digestive system to other parts of the body. There are about 95% of cases that happen to babies younger than 6 months old, but that is rare. The toxin blocks nervous system signals which  tell your muscles when to activate and when to relax and it blocks those signals that cause paralysis also known as floppy baby syndrome lasting weeks or months due to nerve damage from the toxin. Most infants do make a full recovery with treatment, but the body gradually repairs the nerve endings, though recovery can take several months to a year. It can be deadly when the paralysis blocks signals to the muscles you use to breathe. 

When seeking a healthcare provider at a hospital or emergency room they can suspect infant botulism based on your baby’s symptoms and by doing a physical exam and neurological exam. Another way of diagnosis is lab testing as it can test the toxin inside the body. Most likely a provider can confirm if your baby has infant botulism by testing their stool. Infant botulism is extremely treatable; for babies, the treatment starts with an antitoxin called botulism immune globulin (BabyBIG), and it will be through an intravenous (IV) line. This antitoxin works like an antidote, neutralizing the toxin circulating in your baby’s blood.

Antibiotics aren’t usually part of the treatment for infant botulism. The bacteria make the toxin release it when they die, so antibiotics can actually make your baby sicker. The exception to this is for treating other infections that your baby has at the same time.

In the past year, there have been recent outbreaks involving this rare condition. On November 19th, 2025, ByHeart, an independent infant nutrition company founded in 2016, reported that testing of unopened ByHeart infant formula at a third-party lab was identified. The California Department of Public Health confirmed the presence of Clostridium botulinum type A in a culture from an opened can of ByHeart infant formula that was fed to a sick infant. Human Botulism Immune Globulin Intravenous (BIG-IV)3 is the only Food and Drug Administration approved treatment for infant botulism caused by BoNT types A and B which is responsible for 99% of infant botulism in the United States. BIG-IV is sponsored, produced, and distributed by the Infant Botulism Treatment and Prevention Program (IBTPP) at the California Department of Public Health. The deployment of BIG-IV serves as a surveillance mechanism to identify cases nationally. In late October 2025, the IBTPP deployed BIG-IV to three hospitalized neonates who had consumed ByHeart powdered infant formula prior to the onset of the illness. One was a California neonate whose stool specimen tested positive for BoNT type A at CDPH Microbial Diseases Laboratory and Botulism Reference Unit, confirming the diagnosis of infant botulism. In parallel, the IBTPP received laboratory reports confirming type A infant botulism for two patients treated in Pennsylvania and Rhode Island. Whole-genome sequencing of the isolate from the Rhode Island patient’s stool revealed C. botulinum subtype A1. Detection of type A is rare east of the Mississippi River. This was the first type A case identified in Rhode Island, and 98% of cases in Pennsylvania are type B. Case investigation by IBTPP noted ByHeart powdered infant formula exposure in both patients. 

On November 8, 2025, ByHeart recalled two lots of powdered infant formula associated with recent cases. Then on November 11, 2025, ByHeart voluntarily recalled all infant formula products following the identification of additional suspected patients with infant botulism, expanded lot code associations, and reported preliminary positive results for C. botulinum type A in the powdered infant formula sample tested by CDPH MDL. ByHeart partnered with IEH Laboratories to test unopened products. On December 23, 2025, the firm reported positive test results for Clostridium botulinum in six of 36 samples of finished product from two lots. As of December 10, 2025, 51 cases of suspected or confirmed infant botulism and exposure to ByHeart powdered infant formula had been reported across 19 states, and all patients affected by this toxin required hospitalization, however, there has been no outbreak-associated deaths reported since then in 2026.

Infant botulism develops more slowly and more gradually than it does in adults. But diagnosing and treating this condition especially among the infant population and doing so quickly is still important. In calling your child’s pediatrician they can advise you on what to do. But when in doubt, it’s better to be safe and take your baby to the nearest hospital or emergency room.