Waterborne Pathogen Considerations in the NICU

Evi Dewhurst

Neonatal intensive care units have vigorous cleaning and disinfecting standards for patient safety, with good reason. Immunocompromised infants are at increased risk of infection from bacteria contaminating various surfaces, unwashed hands, water, and a whole host of other culprits. The impact of exposure to certain types of bacteria can quickly result in further health problems, a need for additional treatment, increased length of stay, or worst-case scenario, death.

One of these seemingly innocuous culprits of bacteria is water. At-risk infants are potentially exposed to waterborne pathogens in the NICU for a variety of reasons, one of which is the task of warming infant feeds. Warming infant feeds in neonatal intensive care is a common practice, due most in part to the assumed and tested benefits of reduced residuals, lessened body temperature impact, and better tolerance of the feed itself. Currently there are multiple ways to warm these feeds in the NICU, each offering its own level of effectiveness, efficiency, and safety. Cup and water warming methods, however, expose infants to infection and bacteria pathogens known to thrive in water. These include:

-Pseudomonas aeruginosa

-Stenotrophomonas maltophilia

-Acinetobacter species

-Legionella species

-Klebsiella pneumonia




-Atypical mycobacteria




Waterborne Pathogens Enteral Warming Prep


That list is alarming, and quite frankly, makes my skin crawl. Who knew tap water could have so many hidden pathogens?

Logically at this point you might be thinking, can’t these pathogens be avoided by using a certain water temperature? Unfortunately, waterborne pathogens are hardy specimens with the ability to survive and flourish in cold or hot water coming through the tap.

Another concern is the assumption of pathogen reduction while using non-touch electronic faucets. Certainly they are a wonder of technology and a great way to prevent touch contamination from repeated handling of the on/off handles when washing hands. However, from the health view of water-borne bacteria exposure, they are not so nice. These types of faucets pose a hidden infection risk: The electric solenoid valves, which are warm, strengthen planktonic growth and biofilm bacteria. Biofilm is a natural occurrence in plumbing systems, and actually shelters bacteria from disinfection. While the bacteria grow in the dark, wet environment, the warmth of solenoid valves creates only more fruitful opportunity to multiply. While fine for washing hands (primarily when using a disinfecting soap), this type of tap water source should not be encouraged for use when preparing feeds for NICU infants.

Another misconception is that certain types of heated water systems can reduce flourishing pathogens in plumbing. Sadly, this is also largely untrue. Hot water systems in healthcare facilities have recirculation loops, which can actually cultivate microbes. Clinicians are often surprised to learn about the recirculation. If your hospital offers such a system, ask about how it functions. It is best to have a clear understanding of your facility water system in order to make informed decisions when it comes to patient water exposure. While the convenience of heated water systems may increase efficiency, the recirculation loop could create an even larger pathogen issue that could contribute to negative outcomes when using it to warm NICU feeds.

Warming enteral feeds in the NICU need not risk exposure to these waterborne pathogens. If you currently employ a warming method which places enteral feeding disposables or nourishment in a tap water environment, consider investigating alternative methods. These waterless warming methods offer the efficiency, safety and reliability your unit requires, and often provide additional advantages over water warming methods. Moving away from water-based warming should be on your agenda as part of your infection reduction goals.



1. Molina-Cabrillana J, Artiles-Campelo F, Dorta-Hung E, et al. Outbreak of Pseudomonas aeruginosa infections in a neonatal care unit associated with feeding bottles heaters. American Journal of Infection Control. Feb 013;41(2):e7-9.

2. Cervia, JS, Ortolano, GA, Canonica, FP. Hospital Tap Water: A Reservoir of Risk for Health Care-Associated Infection. Infectious Diseases in Clinical Practice. 2008; 16(6):349-353


The Medela Guardian Warmer was designed to deliver a warmed neonatal enteral feed without water.
Learn more about the Medela Guardian Warmer

The Medela Waterless Milk Warmer is perfect for warming all types of milk feeds, without the use of water.
Learn more about the Medela Waterless Milk Warmer TM


About the Author

Evi Dewhurst is a Senior Manager, Marketing Communications for Medela, Inc. As a proud mother of two young children, she is passionate about healthcare for youngsters everywhere and has a serious soft spot for babies. She is part of the dedicated team at Medela, who together are committed to designing and manufacturing products to advance human milk healthcare. Have a question? Evi can be reached at evi.dewhurst@medela.com