CDC Says ByHeart Infant Formula Botulism Outbreak Is Over: What Parents Should Know Now

Bottom line for parents: The Centers for Disease Control and Prevention (CDC) says the multistate infant botulism outbreak linked to ByHeart Whole Nutrition Infant Formula is over. A total of 48 infants became ill, and no deaths were reported. If you still have recalled ByHeart formula at home, do not use it. And if your baby has symptoms of infant botulism, seek medical care right away.

What happened

In November 2025, federal health officials began investigating cases of infant botulism in several states. The CDC later confirmed that the illnesses were linked to ByHeart Whole Nutrition Infant Formula.

According to the CDC, 48 infants were sickened in the outbreak. Many required hospitalization, but no deaths were reported. In late February 2026, the CDC announced that the outbreak had ended after no new cases were identified.

The Food and Drug Administration (FDA) expanded its recommendations during the investigation to include all ByHeart formula products. The agency also took steps to improve recall effectiveness and retailer compliance, including working to ensure recalled products were removed from store shelves.

What investigators found

Botulism is caused by toxins produced by the bacterium Clostridium botulinum. In infants, the bacteria can grow in the intestines and produce toxin, leading to muscle weakness and other serious symptoms.

According to the FDA’s outbreak investigation page, laboratory testing identified Clostridium botulinum in finished formula products and in a lot of powdered whole milk used in manufacturing. Federal officials reported that the bacterial strain found in some products matched the strain identified in affected infants.

However, regulators have said the exact source of contamination within the supply chain remains under investigation. That means officials identified contaminated ingredients and products, but have not yet publicly detailed how or when contamination occurred.

What is infant botulism?

Infant botulism is a rare but serious illness that primarily affects babies under 12 months old. Unlike foodborne botulism in adults, infant botulism occurs when spores grow in a baby’s intestines and produce toxin.

According to the CDC, symptoms can develop days to weeks after exposure and may include:

Constipation (often the first sign)
Poor feeding or weak suck
Weak cry
Low muscle tone (“floppiness”)
Drooping eyelids
Breathing difficulties

Symptoms can worsen quickly. Infant botulism is considered a medical emergency.

What to do if you have ByHeart formula

If you have ByHeart formula purchased during the affected timeframe:

Do not use it.
Check lot numbers and recall notices through the FDA or the company.
Follow refund or disposal instructions provided by the manufacturer or retailer.

The FDA has emphasized recall compliance and removal of affected products from stores, but parents should still double-check products at home.

When to seek medical care

Call your child’s healthcare provider immediately or seek emergency care if your baby shows signs of:

Weakness or unusual floppiness
Difficulty feeding
Breathing trouble
Reduced movement or alertness

Early treatment improves outcomes. The primary treatment for infant botulism is a specialized antitoxin known as BabyBIG (Botulism Immune Globulin Intravenous), which can shorten hospital stays and reduce complications when given promptly.

Why this outbreak matters

Infant formula is often the sole source of nutrition for babies, which makes contamination especially concerning. Although infant botulism remains rare in the United States, this outbreak highlights how quickly illnesses can spread when widely distributed products are affected.

The FDA’s announcement about strengthening recall effectiveness reflects broader concerns about how quickly contaminated products are identified and removed. For families, this is not just about one brand — it is about understanding recall notices, watching for symptoms, and knowing when to act.

What we still don’t know

While testing identified contamination in finished formula and in a powdered whole milk ingredient, federal agencies have not yet publicly released a full root-cause analysis explaining exactly how contamination entered the supply chain.

Investigations like this can take months, particularly when multiple facilities, suppliers, and production batches are involved.

What this means for parents now

The outbreak has officially ended, and no new cases are being reported. That is reassuring. But awareness remains important:

Stay alert to product recalls involving infant foods.
Keep lot numbers and packaging until a container is finished.
Seek medical care promptly if symptoms develop.

Infant botulism is rare, and most babies recover fully with treatment. The key is early recognition and fast care.

For the most current updates, parents can review information from the CDC and FDA, which continue to post investigation summaries and regulatory updates.

Sources

This article is for general informational purposes only and is not medical advice. Research findings can be early, limited, or subject to change as new evidence emerges. For personal guidance, diagnosis, or treatment, consult a licensed clinician. For current outbreak or public health guidance, follow your local health department, the CDC, or another relevant public health authority.