In vitro evaluation of efficacy of 5 methods of disinfection on mouthpieces and facemasks contaminated by strains of cystic fibrosis patients☆

Abstract 

Introduction

Home-nebulizers are a potential source of bacterial infection of the respiratory tract in patients suffering from cystic fibrosis. Recommendations for disinfecting this equipment are often arbitrary and sometimes contradictory.

Objective

To assess in vitro the effectiveness of 5 methods of disinfecting this equipment.

Methods

160 mouthpieces and 160 masks of nebulizers were artificially and massively contaminated with 16 strains of germs found in patients with cystic fibrosis (Staphylococcus aureus, Pseudomonas aeruginosa, Stenotrophomonas maltophilia, Burkholderia cenocepacia, Alcaligenes xylosoxydans). A controlled comparison was carried out of the five methods of disinfection (hypochlorite solution (0.02% active chlorine), acetic acid 3.5%, Hexanios 0.5%, washing-up detergent 0.5% and a dishwasher), tested with and without drying. Standardised bacteriological sampling took place 4 h after disinfecting.

Results

Following treatment, the disappearance of the germ was recorded in 84.1% of cases, and effective disinfecting (reduction>5 log CFU/mL) in another 10.6%. Disinfection failure (5.3%) was found almost only in the case of acetic acid against Staphylococcus aureus.

Conclusion

With the exception of acetic acid, the methods of disinfecting tested in this study appeared to be effective against common bacterial pathogens in cystic fibrosis.

Keywords: Contamination, Cystic fibrosis, Disinfection, In vitro, Nebulizer