Aromatherapy in Health Care Settings—A Source of Drug-Resistant Bacterial Infections?

Hospitalization and medical care can be stressful, and many patients are trying to find ways to reduce the anxiety. For example, requests from women to incorporate aromatherapy through essential oils into their birthing experience are increasing. Although there is some evidence that using aromatherapy prior to and during delivery can result in a reduction in anxiety, fear, and/or pain in labor, there are challenges with this practice in terms of infection control. Indeed, reviews are mixed regarding the medical applications of aromatherapy; however, the fact remains that the popularity of essential oils remains high. Sadly, a recent outbreak of an extensively drug-resistant Pseudomonas aeruginosa (XDR-PA) infection has revealed how aromatherapy can pose a high risk to patient safety.

Aromatherapy can be administered 2 ways: through a diffusing machine (which requires water), or direct application of the oil onto parts of the body. Understandably, from an infection-prevention perspective, there is concern that diffusers may pose a challenge for disinfection and put patient(s) at risk for waterborne infections with pathogens such as Legionella or P. aeruginosa. The quick and rising popularity of aromatherapy use in health care settings means that these institutions may not have processes in place to ensure patient safety.

This may have been the case at the University Hospital of Innsbruck, which is a tertiary care facility that houses 1600 beds. The hospital staff maintain patient screening on admission (oropharyngeal, rectal, and nasal) as a way to maintain active infection prevention; however, when they began to see an increase in infections with extensively resistant XDR-PA from multiple sites across 7 patients in the surgical intensive care unit (SICU), the infection prevention staff knew something was afoot.

In their quest to find the source of this increased rate of XDR-PA, they found several infection control failures, such as the fact that patient wash water was discharged directly into the basins in the patient’s room instead of within a dedicated sink to avoid splash-back and contamination, and medical devices were placed within the splash-contaminated zone. Although these are actions likely to occur in hospitals everywhere, 1 particular observation raised a red flag. Patients had been using oil for an aromatherapy body treatment and the same bottle was used across 7 of the patients who were positive (either colonized or infected) for XDR-PA.

When the staff took additional environmental samples to identify the source of the infection, they found that of the 145 samples, 4.1% had XDR-PA present. The highly-resistant pathogen was found in the wash basins and the patient aromatherapy oil.

To decipher whether or not the aromatherapy bottles arrived contaminated, the team tested an unopened bottle, which came back negative.

The staff then implemented infection prevention practices to reduce the transmission. They separated the patients into cohorts and discontinued putting wash water into the basin. In addition, they no longer allowed the sharing of aromatherapy oil.

The outbreak of XDR-PA across these 7 patients lasted for 24 days and was ultimately deemed nosocomial. What pointed to the aromatherapy was that all 7 patients received the care oil, which had been directly applied by nurses. Further investigation suggested that the patients likely contaminated the environment (ie, basins, etc) rather than the oil, and that the oil was contaminated directly by a patient via a health care worker or the discharge of the basin water contaminated the area where the oil was stored. Improper storage and sharing of the oil is a likely risk factor for contamination and thus transmission, meaning that hospitals should utilize single-patient containers if they allow aromatherapy.

Overall, the risks of diffusers are considerable and if patients are requesting essential oils, topical application with single-patient bottles should be considered; however, ultimately, each facility should ensure they have a designated policy and plan in place.