Majority of Home Nebulizers Used by CF Children Contaminated with Microorganisms, Leading to Exacerbated Symptoms, Study Finds

More than 70% of home nebulizers used by children with cystic fibrosis (CF) are contaminated with microorganisms, posing a serious potential health risk to patients and underscoring a significant need for educational programs focused on nebulizer maintenance and hygiene, a research study found.

The study also found a significant correlation between patients with contaminated nebulizers and exacerbations of CF symptoms, leading to hospitalization and the need for intravenous (IV) antibiotics.

The findings of the study were published in “Microbial contamination of home nebulizers in children with cystic fibrosis and clinical implication on the number of pulmonary exacerbations,” an article in the journal BMC Pulmonary Medicine.

Nebulizers are a pivotal component of CF treatment, as they allow for targeted delivery of therapies to the lungs. Having these nebulizers at home allows patients to stay on top of their symptoms and avoid unnecessary trips to the hospital. However, having these devices outside of the sterile hospital environment increases the risk of their contamination.

The Cystic Fibrosis Foundation provides guidelines for home nebulizer care, but potential problems can still occur if the directions are not properly understood or followed. This is especially relevant for the CF community, as people with the inheritable progressive disease are typically more susceptible to lung infections.

Now, researchers from the Shahid Beheshti University of Medical Sciences in Tehran, Iran, sought to investigate the clinical implications of microbial contamination of home nebulizers. They analyzed samples from home nebulizers of 61 Iranian children with CF — mean age of 7.6 years — between September 2017 and March 2018.

All patients had a single home nebulizer that was used at least once per day. The children and their families were specifically instructed to clean the nebulizer after its use on the evening prior to their scheduled outpatient visit, and to bring their home nebulizers with the facial mask/oral piece and any connectors.

The team collected samples from the mouthpiece, reservoir, and connectors of the nebulizer devices using cotton swabs. These were then monitored for the growth of any microbial colonies.

Sputum samples or deep nasopharyngeal swabs also were collected from each patient to test for the presence of microorganisms. Medical records over the 12 months prior to enrollment in the study were assessed to determine the number of disease exacerbations.

The results showed that 43 (70.5%) of the nebulizers were contaminated, while 18 showed no contamination. Microorganisms were found in 31 mouthpieces (50.8%), 21 reservoirs (34.4%), and 11 connecting tubes (18%). A total of six nebulizers contained contaminants in all three components, while eight had two contaminated components; 29 had one component with contamination.

Among the contaminated nebulizers, 24 (39.3%) contained microorganisms that are considered potentially harmful — namely Pseudomonas aeruginosa and Staphylococcus aureus. The most common organism to be isolated, P. aeruginosa — the key bacterial agent of CF lung infections — was recovered from 19 nebulizers.

Patient samples revealed the presence of P. aeruginosa in 16 of the 19 children with contaminated nebulizers. The other three patients tested positive for P. aeruginosa within one year prior to the start of the study.

Importantly, among the 24 patients who had nebulizers contaminated with harmful microbes, the rate of exacerbated CF symptoms requiring hospitalization and IV antibiotics was 1.5 per year. That compared with 0.4 per year for the 19 patients who had a non-harmful microbe contamination.

To eliminate a potential source of bias, the researchers examined the frequency with which each patient used the nebulizer per day. The findings demonstrated that there was no significant difference in usage between the contaminated (mean of 2.39 inhalations per day) and non-contaminated (mean of 2.67 inhalations a day) groups. That indicated that elevated rates of nebulizer use does not account for a higher likelihood of contamination.

Finally, the team probed the nebulizer cleaning habits of each family to evaluate how closely they were following the recommended guidelines for device cleanliness. The maintenance guidelines include a cleaning step, a disinfecting step, a rising step, and a drying step. It is recommended that the nebulizer be cleaned after every use.

Only 16 of the 61 nebulizer owners (26.2%) followed all of the cleaning and maintenance guidelines correctly for frequency, cleaning, disinfection, and drying, the researchers found.

These findings also showed that the mean age of children in households with substandard nebulizer care was 8.4 years, compared with a mean age of 5.3 years in households that completely followed the guidelines.

Based on the results, the team concluded that “the majority of domiciliary nebulizers used by children with CF were contaminated with microorganisms, indicating that the nebulizers may serve as potential reservoirs of pathogens for the patients’ lung.”

Better decontamination is needed to prevent ongoing infections, they said.

The researchers also emphasized that “further educational programs regarding the nebulizer hygiene in CF children is required.

“The negative impact of contamination of nebulizer on CF exacerbation requires serious attention and further investigations,” they said.