Botulism Explained: Symptoms, Risks, Treatment, and Prevention in Infants and Adults

The CDC confirms that an outbreak of botulism has affected 59 infants in 19 states across the US since December 2023. The source of this outbreak is believed to be contaminated baby formula linked to ByHeart products, which have now been recalled as investigations continue.

Botulism is a rare but potentially life-threatening disease caused by Clostridium botulinum, a gram-positive, spore-forming bacterium that grows in environments with little to no oxygen, such as soil and marine sediments.¹ It is rare, but when it strikes, it can progress fast to respiratory failure if not recognized and treated promptly,” says John Abroon, MD, a board-certified internist in New York. “Mortality used to be as high as 60% before ventilators. With modern intensive care and timely antitoxin, the mortality rate is generally under 5% [to]10%, but delays in diagnosis or a lack of ventilation can push it higher,” he adds.

C botulinum produces soluble toxins that, when ingested, affect the nervous system, resulting in muscle paralysis, respiratory difficulties, and even death. Seven different types of botulinum toxins are known (A, B, C, D, E, F, and G).² Although most forms of C botulinum produce only 1 toxin, some strains are known to produce more than 1. Being the most potent neurotoxin known to man, even as little as 1 mcg/kg of botulism neurotoxin (BoNT) is considered lethal, although the precise lethal dose is not known.³

“Early illness can feel mercurial for patients because the symptoms evolve very quickly, over hours, which is why minutes matter for airway protection and antitoxin,” Abroon says.

There are 3 main kinds of botulism: foodborne botulism, wound botulism, and infantile botulism. Infantile botulism is currently the most common form, implicated in about 70% of new cases.³

Fortunately, botulism is not contagious. Instead, it spreads when C botulinum enters body tissues through the mouth or wounds, and very rarely through inhalation of large quantities of spores. Inhalation botulism does not occur naturally and is associated with bioterrorism.⁴

Shortly after toxins enter the bloodstream, they are transported to peripheral nerves, where they cause nerve palsies by inhibiting nerve signal activity. Toxin type A is generally considered the most dangerous of the botulinum toxins, with most infected individuals requiring mechanical ventilation at some point.⁵

While foodborne botulism is transmitted when one ingests preformed botulinum toxins in contaminated food, infantile botulism occurs when a child under 1 year old consumes a substance contaminated with Clostridium botulinum spores.⁶ These spores eventually colonize the intestinal tract, where they begin to produce neurotoxins.

C botulinum spores themselves are resistant to heat. However, heat exposure neutralizes their toxin.⁷ Therefore, one is more likely to contract botulism when one consumes contaminated ready-to-eat, packaged foods like beans, beef, vegetables, etc, that have not been boiled.

The incubation period of botulism varies depending on the type of botulism involved. Foodborne botulism typically produces symptoms within the first 12 to 48 hours. The initial symptoms include nausea, vomiting, weakness, and dizziness; followed by dry mouth, blurry vision, and difficulty speaking. There may be muscle weakness of the neck and arms that progresses to involve the respiratory muscles and the muscles of the lower body. Muscle weakness in botulism follows a head-to-toe pattern affecting both sides of the body. Other symptoms include urinary retention, low blood pressure, and constipation. Foodborne botulism is fatal in around 5 to 10% of cases, especially when prompt diagnosis and treatment are not made, and respiratory failure occurs.⁸

Infantile botulism, on the other hand, begins to produce symptoms between 3 and 30 days after consuming formula containing C botulinum spores. The early signs of infantile botulism include constipation, poor feeding, weak suck, tiredness, and loss of head control. This progresses to include “floppy baby syndrome,” facial weakness, breathing difficulties, and respiratory distress.⁸

Treating botulism in people older than 12 months involves supportive care and the administration of a botulinum antitoxin. When administered early, ideally within 24 to 48 hours of symptom onset, this antitoxin prevents progression of paralysis by neutralizing circulating toxins. However, it does not reverse any paralysis that has already occurred.⁸

For infantile botulism, the mainstay of treatment is botulinum immune globulin (BabyBIG), which contains antibodies against the botulinum toxin. It is administered intravenously; the dose is measured by weight. Prognosis is good if treatment is initiated early. Most infants will recover within a few months to a year after receiving necessary health care.³

Foodborne botulism can be prevented by inhibiting the growth of C botulinum spores and/or the ingestion of their toxins. This is achieved by making foods uninhabitable for C botulinum.

Low-acid foods, such as vegetables, poultry, meat, fish, and seafood, should be canned under high-pressure processing. These cans should be properly stored and inspected before consumption. Consumers should check expiration dates and examine cans for any punctures, dents, or signs of opening.⁹

After opening, boil canned foods for up to 10 minutes. Refrigerate after opening if you plan to eat it more than once. If you are ever in doubt about the food, you should discard it.⁹

Do not give infants honey or products made from it. Also, examine all baby formula to ensure the seals are unbroken.

“Clinicians should tell parents to throw away any ByHeart Infant formulas and be on high alert for symptoms in their infants ranging from constipation (usually the first sign) to poor feeding, drooling, and muscle weakness that makes the baby appear weak or floppy. Parents of infants with these symptoms should seek medical care immediately, “ says Nada Mallick, MD, MBA, a board-certified pediatrician and critical care specialist in Washington.

The FDA has recommended the immediate stoppage and recall of ByHeart baby formula products.¹⁰ And physicians are urged to be on the lookout for early signs of botulism in infants and begin treatment using BabyBIG following consultation.¹¹ Even before the lab results show up. All cases should be reported to the local or state health authorities.

Recent research has focused on improving the diagnosis of botulism using approaches suitable for clinical use, food testing, and environmental monitoring.¹²

However, there remains an urgent need for faster diagnostics and more accurate food-testing methods to prevent further outbreaks of this deadly condition. For now, a high index of suspicion, prompt treatment, and continued vigilance are our best defense.

^References

1. Clostridium botulinum. United States Department of Agriculture, Food Safety and Inspection Service. Updated February 2021. Accessed December 17, 2025. https://www.fsis.usda.gov/sites/default/files/media_file/2021-02/Clostridium_botulinum.pdf
2. Sobel J. Botulism. Clin Infect Dis. 2005;41(8):1167-1173. doi:10.1086/444507
3. Van Horn NL, Shah M. Infantile botulism. In: StatPearls [Internet]. 2025. Updated April 6, 2025. Accessed December 17, 2025. PMID: 29630230.
4. Arnon SS, Schechter R, Inglesby TV, et al. Botulinum toxin as a biological weapon: medical and public health management. JAMA. 2001;285(8):1059-1070. doi:10.1001/jama.285.8.1059
5. Rao AK, Sobel J, Chatham-Stephens K, Luquez C. Clinical guidelines for diagnosis and treatment of botulism, 2021. MMWR Recomm Rep. 2021;70(2):1-30. Accessed December 17, 2025. https://www.cdc.gov/mmwr/volumes/70/rr/rr7002a1.htm
6. Griese SE, Kisselburgh HM, Bartenfeld MT, Thomas E, Rao AK, Sobel J, Dziuban EJ. Pediatric botulism and use of equine botulinum antitoxin in children: a systematic review. Clin Infect Dis. 2018;66(suppl 1):S17-S29. doi:10.1093/cid/cix812
7. Munir MT, Mtimet N, Guillier L, et al. Physical treatments to control Clostridium botulinum hazards in food. Foods. 2023;12(8):1580. doi:10.3390/foods12081580. PMID: 37107375; PMCID: PMC10137509.
8. Botulism. World Health Organization. Published January 10, 2018. Accessed December 17, 2025. https://www.who.int/news-room/fact-sheets/detail/botulism
9. Prevention of botulism. Published 2024. CDC. Accessed December 17, 2025. https://www.cdc.gov/botulism/prevention/index.html
10. Outbreak investigation: infant botulism, infant formula (November 2025). US Food and Drug Administration. Published November 2025. Accessed December 17, 2025. https://www.fda.gov/food/outbreaks-foodborne-illness/outbreak-investigation-infant-botulism-infant-formula-november-2025
11. Infant botulism: clinical overview. CDC. Published 2024. Accessed December 17, 2025. https://www.cdc.gov/botulism/hcp/clinical-overview/infant-botulism.html
12. Wang S, Zhang H, Xue Y, Yang Y, Yuan L. Research progress on the detection methods of botulinum neurotoxin. Toxins. 2025;17(10):453. doi:10.3390/toxins17100453