Outbreak Investigation of Infant Botulism linked to Whole Nutrition Infant Formula

United States

Update February 26th, 2026:
The FDA and CDC report that the multistate infant botulism outbreak linked to ByHeart Whole Nutrition infant formula has been declared over. No new cases have been identified since December 10, 2025, and three previously reported cases were later determined to be unrelated and removed from the total.

As of February 26, 2026, the investigation includes 48 total cases, consisting of 28 confirmed and 20 probable infant botulism cases. All cases resulted in hospitalization. The last illness onset date was November 29, 2025.

Additional laboratory analysis using whole genome sequencing (WGS) found new genetic matches between Clostridium botulinum detected in finished formula, ingredients, and clinical samples. Two newly analyzed samples of organic whole milk powder collected at a supplier facility matched previously identified strains linked to the outbreak. Additional clinical isolates also matched strains found in formula and ingredient samples.

Investigators have identified multiple strains of the bacterium across product, ingredient, and patient samples. Due to the complexity of the organism, the FDA has not yet determined the exact root cause of contamination, and the source investigation remains ongoing.

The FDA has transitioned from active outbreak response to post-incident review, which may include continued surveillance, compliance actions, and additional research related to powdered infant formula safety.

Source: FDA


Update January 23rd, 2026:
The FDA and CDC report that no new infant botulism cases have been added since the December 10, 2025 update, indicating that reported illnesses linked to this outbreak have stabilized.

As part of the ongoing investigation, two FDA-collected samples tested positive for Clostridium botulinum (toxin), Type A. One positive sample was a sealed ByHeart powdered infant formula product, which genetically matched a clinical isolate from an affected infant based on whole genome sequencing (WGS). These results also matched two samples of organic whole milk powder, an ingredient used by ByHeart, that were previously collected and tested by the company.

A second organic whole milk powder sample, collected by FDA at a supplier’s processor and analyzed by the New York Wadsworth Laboratory, also genetically matched the C. botulinum strain identified in the finished ByHeart infant formula product, according to WGS analysis conducted by ByHeart.

While these findings further clarify the contamination pathway, FDA’s investigation remains ongoing to determine the precise source and contributing factors.

Previously, on December 23, 2025, ByHeart publicly reported positive C. botulinum results in six of 36 finished product samples, originating from two batches included in the initial recall.

The FDA continues investigational activities as needed while the source investigation remains open.

Source: FDA


Update December 17th, 2025:
Federal and state health officials report that no new infant botulism cases have been added since the December 10 update, indicating that case reports linked to this outbreak have slowed.

Going forward, CDC will no longer provide weekly updates and will issue additional communications only if new information becomes available. The FDA will continue investigational updates as needed while the source investigation remains ongoing.

On December 12, 2025, the FDA issued warning letters to four major retailers for failing to remove recalled ByHeart infant formula from store shelves despite prior notification. On December 15, 2025, the FDA also released a public reminder emphasizing retailers’ legal obligations under the Federal Food, Drug, and Cosmetic Act, particularly for recalls involving infant foods.

Additional laboratory testing by ByHeart, FDA, CDC, and state partners is ongoing. Any new positive finished-product testing results will be added to the FDA’s sample results section as they become available.

All ByHeart powdered infant formula products remain under full recall, including cans and single-serve “anywhere pack” sticks, and should not be sold or used.

Source: FDA


Update December 10th, 2025:
Federal and state health officials have expanded the outbreak case definition to include any infant with botulism who consumed ByHeart formula at any time since the product’s launch in March 2022. With this broader criteria, authorities identified 10 earlier cases (December 2023–July 2025) that were previously not counted. These infants also consumed ByHeart formula and were all hospitalized.

As of December 10, 2025, a total of 51 suspected or confirmed infant botulism cases linked to ByHeart powdered formula have been reported across 19 states. Illness onset dates now range from December 24, 2023, to December 1, 2025.

Officials also note that no new reports of recalled formula appearing on store shelves have been received since November 26. All ByHeart powdered formula products remain under full recall and should not be sold in stores or online.

Additional laboratory testing by ByHeart, FDA, CDC, and state agencies is ongoing. Results from finished product testing will be added to the FDA’s sample results section as they become available.

Updated case counts:
- Total illnesses: 51 (12 new)
- Hospitalizations: 51
- Deaths: 0
- Last illness onset: December 1, 2025
- States reporting cases: AZ, CA, ID, IL, KY, MA, ME, MI, MN, NC, NJ, OH, OR, PA, RI, TX, VA, WA, WI
- Distribution: Online, nationwide (including Guam and Puerto Rico), and internationally

Source: FDA


Update December 3rd, 2025:
Federal and state health officials report two additional infant botulism cases, bringing the total to 39 infants hospitalized across 18 states. Illness onsets now range from August 9 to November 19, 2025, and no deaths have been reported. All identified infants consumed ByHeart Whole Nutrition powdered infant formula before becoming sick.

Authorities continue to find recalled ByHeart formula still available for sale at several major retailers (including Walmart, Target, Kroger, Acme, and Shaw’s) despite the full recall. The FDA is working with state partners and retailers to ensure the immediate removal of all ByHeart formula products, including cans and single-serve “anywhere pack” sticks.

Additional product testing is ongoing. On November 19, ByHeart reported that 5 out of 36 formula samples from three lots tested positive for Clostridium botulinum Type A; the affected lot numbers have not been released. Testing by the FDA, CDC, CDPH, and other state agencies continues.

International distribution data confirms that the recalled ByHeart formula reached multiple global markets. Consumers worldwide are advised not to use any ByHeart infant formula, as all lots remain under full recall.

Updated Case Counts
- Total Illnesses: 39 (2 new)
- Hospitalizations: 39
- Deaths: 0
- Last Illness Onset: November 19, 2025
- States Reporting Cases: AZ, CA, ID, IL, KY, MA, ME, MI, MN, NC, NJ, OR, PA, RI, TX, VA, WA, WI
- Distribution: Nationwide (including Guam and Puerto Rico) and international

Source: FDA


Update November 26th, 2025:
Federal and state health officials report six additional infant botulism cases, bringing the total to 37 infants with suspected or confirmed illness linked to ByHeart Whole Nutrition powdered infant formula. Cases have now been identified in 17 states, with illness onsets reported through November 19, 2025. All affected infants have been hospitalized, and no deaths have been reported.

Caregiver interviews continue to confirm that all 37 infants consumed ByHeart powdered formula before becoming ill.

Despite the nationwide recall, the FDA continues to receive reports of recalled ByHeart formula still being found on store shelves across multiple major retailers. The agency is working with states and retailers to ensure immediate product removal. All ByHeart powdered infant formula products (including cans and single-serve “anywhere pack” sticks) remain under a full recall and should not be used or sold in any location, including international markets.

Regulatory agencies are also conducting expanded testing, including analyses of samples collected by ByHeart, FDA, CDC, and state partners. Positive findings to date include Clostridium botulinum type A detected in an opened can and additional samples tested by the company. Testing is ongoing.

The FDA has released updated inspection reports and Form 483 observations from past inspections at ByHeart/Blendhouse facilities in Allerton, Portland, and Reading as part of the investigation into the contamination source. On-site inspections are continuing.

Updated case counts:
- Total illnesses: 37 (6 new)
- Hospitalizations: 37 (6 new)
- Deaths: 0
- Last illness onset: November 19, 2025
- States reporting cases: AZ, CA, ID, IL, KY, MA, ME, MI, MN, NC, NJ, OR, PA, RI, TX, WA, WI
- Distribution: Sold online, nationwide (including Guam and Puerto Rico), and distributed internationally

International distribution data provided by Amazon confirms that the recalled ByHeart infant formula reached multiple global markets. Consumers worldwide are advised not to use any ByHeart formula, as all lots are included in the recall.

Source: FDA


Update November 20th, 2025:
Federal and state officials report that recalled ByHeart infant formula continues to appear on store shelves, including at Walmart, Target, Kroger, Sprouts Organic Market, Safeway, Jewel-Osco, Shaw’s, and Star Market locations. The FDA is coordinating with retailers and state partners to ensure the immediate removal of all affected products. All ByHeart powdered infant formula items (including cans and single-serve “anywhere pack” sticks) remain under full nationwide recall and should not be sold online or in stores.

Officials have also confirmed that the ByHeart formula was shipped internationally through online sales. Consumers outside the United States are advised not to use any ByHeart products, as all lots are included in the recall. Details on international distribution have been released by the FDA.

As part of the ongoing investigation, ByHeart reported that third-party testing of retained, unopened formula from its facility detected Clostridium botulinum in some samples. The company is continuing additional testing to determine the contamination source.

Further updates will be provided as new information is available.

Source: FDA


Update November 19th, 2025:
Federal and state agencies report eight new cases, bringing the total to 31 infants with suspected or confirmed botulism linked to ByHeart Whole Nutrition powdered infant formula. Cases now span 15 states, with illness onsets reported through November 13, 2025. All affected infants have been hospitalized, and no deaths have been reported.

Health officials continue to confirm additional cases and gather detailed exposure information. Ongoing interviews indicate that all 31 infants consumed ByHeart powdered infant formula prior to becoming ill.

Regulators have also confirmed that the recalled ByHeart formula is still appearing on store shelves in several states, despite the full nationwide recall. The FDA is working with retailers and state partners to remove any remaining product. The agency also reiterated that all ByHeart infant formula products (including cans and single-serve sticks) were recalled and should not be used, noting that some were shipped to international customers as well.

Testing and analysis remain in progress. CDPH previously identified Clostridium botulinum type A in an opened can tied to one of the cases, while the FDA’s testing of the unopened product is still underway. Due to the difficulty of detecting this pathogen in powdered formula, officials note that negative results do not rule out contamination.

The investigation continues as the FDA works to determine the point of contamination. Further updates will be provided as new information becomes available.

Source: FDA


Update November 14th, 2025:
The FDA has begun conducting onsite inspections and collecting product samples as part of the ongoing investigation into the ByHeart infant formula botulism outbreak. This follows preliminary testing by the California Department of Public Health, which detected Clostridium botulinum in an open can of ByHeart formula associated with one of the illnesses. Additional laboratory analysis is still underway.

The FDA also confirmed that ByHeart expanded its nationwide recall on November 11, 2025, now covering all of its powdered infant formula products, including both cans and single-serve sticks.

Case Counts
- Total Illnesses: 23
- Hospitalizations: 23
- Deaths: 0
- Last Illness Onset: November 11, 2025
- States with Cases: AZ, CA, IL, KY, MI, MN, NC, NJ, OR, PA, RI, TX, WA
- Product Distribution: Online and nationwide

Source: FDA


Update November 13th, 2025:
The FDA has initiated an inspection and sample collection.

Source: FDA


Update November 11th, 2025:
The FDA and CDC have reported two additional infant botulism cases, bringing the total to 15 confirmed or suspected illnesses across 12 states. All affected infants had consumed ByHeart Whole Nutrition powdered infant formula, and all have been hospitalized.

Preliminary testing by the California Department of Public Health detected Clostridium botulinum bacteria in an open can of ByHeart formula (lot 206VABP/251131P2) linked to one of the cases. Additional testing is underway.

Following the FDA’s request, ByHeart expanded its recall on November 11, 2025, to include all its infant formula products nationwide, covering both cans and single-serve sticks. The investigation remains ongoing to determine the source of contamination.

Updated case count:
- 15 illnesses (15 hospitalized, 0 deaths)
- Across AZ, CA (2), IL (2), KY, MN, NC, NJ, OR, PA, RI, TX (2), and WA.

Source: FDA


November 9th, 2025:
ByHeart, Inc. has initiated a recall of specific lots of its Whole Nutrition Infant Formula following an outbreak of infant botulism affecting 13 infants across 10 states in the United States (AZ, CA, IL, MN, NJ, OR, PA, RI, TX, WA). The FDA and CDC are investigating the outbreak, which involves the pathogen botulinum toxin type A. No deaths have been reported.

The outbreak, identified between August and November 2025, has led to 13 hospitalizations. All affected infants reportedly consumed ByHeart's powdered formula, with cases confirmed in states such as Arizona, Illinois, and Washington. The formula is sold online and at major retailers nationwide. The FDA has recommended a voluntary recall due to the severity of the illnesses and the strong epidemiological link to the product.

The issue was discovered after the California Department of Public Health's Infant Botulism Treatment and Prevention Program noted an increase in botulism type A infections among infants consuming ByHeart formula. State officials have collected leftover formula for testing, with results pending. The FDA continues to investigate the contamination source and assess if other products are affected.

Source: www.fda.gov/food/outbreaks-foodborne-illness/outbreak-investigation-infant-botulism-infant-formula-november-2025