Cronobacter sakazakii, the bacteria that contaminated a major infant formula manufacturing plant and led to a nationwide shortage, is a common natural pathogen. It’s harmless for most people, but it can be life threatening for infants, especially those who are born prematurely or with weakened immune systems.
Infections caused by the bacteria are rare, but a new report published Friday by the US Centers for Disease Control and Prevention highlights the importance of proper sanitation of breast pump equipment and safe storage and preparation of powdered infant formula.
According to the US Food and Drug Administration, Cronobacter sakazakii can enter homes and other spaces on hands, shoes and other contaminated surfaces. It is “especially good at surviving in dry foods.”
In one case outlined in the new CDC report, a 14-day-old infant was hospitalized in September 2021 with fever, irritability and excessive crying, along with a mouth infection and diaper rash. The genetic makeup of the bacteria found in the infant’s cerebrospinal fluid was a close match to the bacteria found in an open can of powdered formula in the home. A second strain of bacteria was also found on an open water container that was used to prepare the formula.
Most cases of Cronobacter infection are treatable with antibiotics, and this infant made a full recovery after 21 days of intravenous antibiotics.
However, it can lead to meningitis, sepsis and other devastating complications such as permanent brain damage. About 40% of infants who develop meningitis die, according to the CDC.
In a case from February 2022, an infant died two weeks after symptoms developed – despite treatment with antibiotics. This infant was born prematurely, and symptoms included fever, slow heart rate, trouble breathing and seizures.
According to the CDC report, the bacteria matched samples from breast pump devices that were used at home. An interview found that the parts were cleaned in a household sink, sanitized and sometimes assembled while still moist. No bacteria were recovered from the milk samples, milk fortifier samples, breast pump devices from the hospital or unopened powdered formula from the hospital.
“Because of the widespread presence of C. sakazakii in the environment, caregivers of infants should follow safe hygiene, preparation, and storage practices, and learn steps to protect infants from infection,” the authors of the CDC report wrote. They encouraged health care providers to promote increased education around the risks and necessary precautions, particularly for those families with infants who are most at risk.
Cronobacter bacteria was at the center of the nationwide infant formula shortage that started last year.
Multiple popular brands of powdered formula were recalled and production at a major manufacturing plant was halted after the US Food and Drug Administration received reports of four infections, including two deaths, among infants who had consumed formula from the Abbott Nutrition facility. An FDA investigation did detect Cronobacter bacteria in the plant, but genetic testing couldn’t link that bacteria to the sick infants.
According to the CDC report from Friday, most cases of Cronobacter sakazakii infection in infants are “not associated with outbreaks but likely occur because of isolated instances of contamination of infant feeding products and equipment in the home.”
The CDC estimates that there are about 18 invasive infections among infants each year in the US. However, it is not a nationally notifiable condition, so the actual incidence is unknown.
However, in response to the events that led to the formula shortage, the FDA laid out a plan outlining proposed changes to enhance surveillance of infant formula for the bacteria. Among the proposed actions from the FDA was a point to make Cronobacter sakazakii infections among infants a nationally notifiable condition, which would require doctors to report cases to public health officials.