Testing by a team of researchers with the Louis Stokes Cleveland VA Medical Center indicates that sporicidal disinfectants are more effective against the multidrug-resistant fungal pathogen Candida auris than quaternary-ammonium disinfectants, according to a study published today in Infection Control & Hospital Epidemiology.

For the study, the researchers tested 23 disinfectants used for cleaning and disinfecting surfaces at 57 healthcare facilities in 30 states. The products included chlorine- and peracetic acid–based disinfectants, which are sporicidal, and quaternary-ammonium and hydrogen peroxide–based disinfectants, which are not. To test their efficacy against C. auris, the researchers used a three-part soil load containing isolates from four phylogenetic clades of C. auris—including the drug-resistant clade 4 strain AR-0385—and a strain of Candida albicans and then cultured the soiled surfaces after they were treated.

The disinfectants were classified as effective if a greater than 5 log10 reduction in C. auris was achieved.

Overall, five chlorine-based disinfectants and the one peracetic acid–based disinfectant consistently reduced all the C. auris and C. albicans strains by 5 log10 or more, as did three hydrogen peroxide–based cleaners. But the quaternary-ammonium disinfectants were largely ineffective. Only one product reduced C. auris strains by more than 5 log10, but it wasn’t effective against the drug-resistant AR-0385 strain.

Current practices may not cut it

The study authors say that while real-world studies are needed, the findings are important because quaternary-ammonium disinfectants are widely used in US healthcare facilities, which have seen a dramatic increase C. auris colonization and infection in recent years.

“The fact that many patients with C. auris are colonized and only detected through screening increases the likelihood that unrecognized cases may enter facilities where cleaning and disinfection practices may not be sufficient to limit spread,” they wrote.

Read more at University of Minnesota Center for Infectious Disease Research & Policy (CIDRAP).