Cronobacter Meningitis in a Breastfed Newborn: Bacteria Found in Her Breast Pump

In January 2018, the Indiana State Department of Health learned of a case of Cronobacter sakazakii meningitis in a newborn girl who had been fed only her mother's breast milk.

The case

• She was born by induced vaginal delivery at 37 weeks and went home from the newborn nursery after 2 days.
• She was well until 8 days old, when she was admitted with poor feeding, a fever of 100.4°F (38°C) and abnormal movements.
• EEG showed seizures in several areas of the brain; MRI showed multifocal restricted diffusion, leptomeningeal enhancement and patchy areas of bleeding.
• Blood and spinal fluid grew C. sakazakii, a disease-causing gram-negative bacillus.
• She was treated first with meropenem, gentamicin and seizure medicines, then, once sensitivity results came back, with cefepime to finish a 21-day course.
• She went home at 33 days old with early intervention therapy for low muscle tone throughout her body and close monitoring of her development.

How she was fed

From birth she had only breast milk, nursing and expressed. Milk was pumped with a personal electric breast pump, with nothing added — no fortifier, no formula.

• The pump and flanges were wiped with a baby wipe after each use, and only occasionally washed with soap and water.
• Bottles and pump parts were taken apart, hand-scrubbed and air-dried on a towel beside the sink; now and then they were sanitized by boiling or in a microwave steam bag.

The investigation

The state health department, the hospital's clinicians and CDC tested:

• the bacteria from her spinal fluid;
• four samples of expressed breast milk;
• the breast pump kit and parts from her home;
• kitchen surfaces, sampled with sponges.

C. sakazakii was found in the expressed milk, the pump kit, and the sink, drain and drying area next to the sink. By pulsed-field gel electrophoresis (PFGE), the household bacteria were indistinguishable from, or one band different from, the bacteria that infected her.

Why it matters

• C. sakazakii infection is rare, but it can cause sepsis and severe meningitis with high rates of disability and death — usually in babies fed powdered infant formula.
• In breastfed babies it's rarer still, though it had recently been reported in two premature newborns linked to contaminated breast pump parts.
• This case shows it can also strike a healthy, full-term baby fed only breast milk. The bacteria can grow quickly in expressed milk even with no formula added.
• The original source of contamination is unknown, but — as in the earlier cases — the pump kit was contaminated.

What parents and clinicians can do

Breast milk is the best nutrition for newborns, so clinicians should actively support parents and teach breast pump hygiene:

• After every use, take the pump kit apart and clean it — by hand with soap and water, or in the dishwasher.
• Consider sanitizing the kit daily by boiling or steaming, especially if the baby is under 3 months, was born prematurely or has a weakened immune system.

Sources

Based on Sundararajan M, Enane LA, Kidwell LA, et al., "Notes from the Field: Cronobacter sakazakii Meningitis in a Full-Term Neonate Fed Exclusively with Breast Milk — Indiana, 2018," Morbidity and Mortality Weekly Report, Centers for Disease Control and Prevention; a work of the United States government in the public domain.