The number of U.S. infants who contracted botulism after eating recalled Nara Organics baby formula has risen to four, according to the Food and Drug Administration.

The four confirmed cases involve infants in California, Pennsylvania and Washington who consumed Nara Organics Whole Milk Organic Powdered Infant Formula. The product was recalled last month after three infants were hospitalized, and federal officials are continuing to test unopened containers from the affected product lots.

Results from the tests are expected in the “coming weeks,” the FDA said.

The organic baby formula was sold nationwide in Target stores and online at Nara.com. The four infants fell ill between April and May 2026, the FDA said on Monday. 

“Parents and caregivers should stop using Nara Organics Whole Milk Organic Infant Formula immediately,” the FDA said in its statement. “If your child is experiencing symptoms after consuming Nara Organics Whole Milk Organic Infant Formula, seek immediate health care.”

Infant botulism is a rare but serious illness that occurs in children under age 1 whose gut microbiomes are immature. The condition is caused when infants consume bacteria with spores that produce a toxin in the gut. Symptoms include constipation, poor feeding, drooping eyelids, weak muscle tone, difficulty swallowing and breathing problems, among others.

The FDA also urged parents to keep any opened cans of formula because state health departments may want to test the product if their infant develops botulism symptoms.

“Label it ‘DO NOT USE’ and keep it stored in a safe place away from other items you feed your baby for at least a month,” the agency said. “If no symptoms appear after a month, throw the leftover formula away.”

A previous outbreak of infant botulism tied to the formula brand ByHeart led to over 50 illnesses in 19 states.