By Lauren Chan, PhD, C2ST Intern, University of Chicago

As someone who is lucky enough to have multiple tiny humans in their life, I am always on high alert when it comes to baby products and their safety. In the second half of 2025, notifications about infant formula contaminations and recalls had me messaging families with infants to be sure they heard the news. Surprisingly, this is not the only instance of formula contamination in recent years. In fact, multiple issues with formulas led to the launch of Operation Stork Speed in March 2025. This program focuses on increasing the safety and supply of infant formulas in the United States, with a particular focus on testing for contaminations. But what got us to the point of needing a new program to provide safe formula for babies? Let’s talk about recent contaminations, formula shortages, and feeding practices that led to the development of Operation Stork Speed. 

Formula use in the United States

One of an infant’s most important jobs is to grow. To do that, infants need proper nutrition from breast milk or infant formula. In the United States, between 2017 and 2019, an estimated 1.65 billion liters of infant formula were sold. Clearly, many families depend on formula to feed their infants, so consistent access is essential.

 

Recent formula contaminations and shortages

In late 2025, formula safety was called into question. Starting in November 2025, the US Food and Drug Administration (FDA, which oversees infant formula production), and the Centers for Disease Control (CDC, which tracks illness outbreaks) identified multiple infants with suspected or confirmed infant botulism. The common factor? ByHeart Whole Nutrition infant formula. 

Investigations identified Clostridium botulinum (toxin Type A), which causes infant botulism, within multiple batches of sealed ByHeart formula products. 

Botulism is a neuroparalytic syndrome, meaning it attacks the nervous system and causes paralysis. Infant botulism presents as poor feeding, loss of muscle control, and challenges with swallowing. In severe cases, babies experience difficulty breathing and botulism can be fatal. This botulism outbreak led to a voluntary recall of all ByHeart products.

As of Feb 26, 2026, the outbreak has been declared over. In total, a reported 28 confirmed and 20 probable infant botulism cases have been linked to ByHeart formulas. ByHeart made up an estimated 1% of infant formula sales in the US and the recall did not majorly impact formula supply and availability. However, the significant impact on affected families cannot be overstated.

This case is similar to a 2022 formula contamination that, conversely, caused a major formula shortage. American infant formulas are primarily made by three manufacturers: Abbott, Mead Johnson, and Nestle Gerber. These companies control approximately 90% of the US formula market. The 2022 shortage was largely caused by the voluntary closure of a Michigan Abbott infant formula plant. 

The plant closure took place after four infants were reported with Cronobacter sakazakii infections. All four babies were eating infant formulas made at the Abbott plant. Cronobacter is a type of bacteria that can be found in dry foods like infant formulas. Cronobacter infections are rare, but typically present in infants as poor feeding and low energy. In infants with severe cases, Cronobacter can cause secondary infections, seizures, and death. 

At the Michigan plant, the CDC identified traces of Cronobacter within the facility, and the plant stopped producing formulas. Multiple infant formulas made at this plant were also recalled. This facility was producing between 20-25% of the nation’s supply of infant formula. With the facility closure limiting production plus formula recalls pulling products off the shelf, a formula shortage was bound to happen. The 2022 shortage caused a major feeding crisis, up to 90% formula “out of stock” rates in some parts of the US. In response, families were forced to adapt their feeding practices. In some cases, families used dangerous feeding practices, including watered-down formula and homemade formula recipes. 

 

The Impact on Infant Feeding Practices

During the 2022 shortage, one study found the use of watered-down formula increased from a reported 2% up to 29%. This study also found that homemade formula rates increased from 3% to 13%. The American Academy of Pediatrics (AAP) has made statements over the years against watering-down formulas, or making homemade formulas due to the unbalanced ingredient levels and health concerns for babies. Notably, other milks are not necessarily good replacements either. Pediatricians report that both goat milk and evaporated milk have inadequate nutrient content and can cause anemia due to low folic acid and iron content. The FDA has guidance available for infant formula safety. 

An alternative is feeding imported formula. Imported infant formulas sold in US stores are required to meet the FDA requirements for formulas. This includes testing for Salmonella and Cronobacter sakazakii. However, when purchased online, the FDA is unable to monitor and regulate the formula’s safety. Further, imported infant formulas have historically had high tariffs. Tariffs increase formula prices for retailers to stock them and families to purchase. Following the 2022 shortage, a temporary lift of formula tariffs was put into effect through the “Bulk Infant Formula to Retail Shelves Act”. 

 

Is Change on Its Way? 

From these formula contamination and shortage events, it’s clear that improvements are needed to support infant safety and formula supply chains. The Department of Health and Human Services (HHS) and FDA sponsored Operation Stork Speed is focused on increasing contaminant testing in infant formula and other children’s foods. Clostridium botulinum testing is included in Operation Stork Speed as a result of the 2025 outbreak. Other parts of this project include a review of nutrient requirements for infant formulas and imported formula policies. As the Operation Stork Speed launches, we can only hope that formula safety, supply chains, and infant health are at the forefront of this work. In the meantime, communities should support families who could be affected by infant formula contamination and shortages. This includes sharing information about formula recalls, discouraging unsafe feeding practices, and advocating for more secure supply and safety regulations in the formula market.