Candida auris is an emerging fungal pathogen that has become a global health concern. This yeast can cause severe illness, particularly in healthcare settings, and is notable for its ability to resist multiple antifungal medications. Understanding how to control and eliminate C. auris is important for preventing its spread and treating infections.
Understanding the Challenge
Candida auris poses a significant challenge due to several inherent characteristics that make it difficult to eliminate. A primary concern is its multidrug resistance, with some strains showing resistance to all three major classes of antifungal drugs, severely limiting treatment options.
The fungus also exhibits remarkable environmental persistence, capable of surviving on surfaces in healthcare environments for prolonged periods, sometimes for weeks, contributing significantly to its spread within facilities. Furthermore, C. auris can form biofilms, which are protective layers that make the fungus even more difficult to eradicate with disinfectants and antifungal treatments.
Environmental Decontamination Strategies
Controlling Candida auris in healthcare environments relies heavily on thorough cleaning followed by effective disinfection. The Centers for Disease Control and Prevention (CDC) recommends using hospital-grade disinfectants registered with the Environmental Protection Agency (EPA) that are specifically effective against C. auris (EPA List P). If List P products are unavailable, disinfectants effective against Clostridioides difficile spores (EPA List K) may also be used, following their specific instructions.
Sporicidal disinfectants, such as chlorine-based products (e.g., sodium hypochlorite at 1000 ppm or higher) and peracetic acid-based disinfectants, are consistently effective against C. auris. Hydrogen peroxide-based disinfectants have also shown efficacy, with some concentrations effective in short contact times. In contrast, some quaternary ammonium compounds (QACs) may have limited or varied effectiveness, emphasizing the need to check product claims.
Beyond chemical disinfectants, thorough cleaning protocols are important. This involves cleaning and disinfecting high-touch areas and shared or reusable equipment multiple times daily. Newer technologies like UV-C germicidal irradiation and vaporized hydrogen peroxide systems can supplement standard cleaning, but their effectiveness parameters for C. auris are still being evaluated and they should not replace manual cleaning and disinfection.
Treating Human Infections
Treating Candida auris infections primarily involves antifungal medications, though the approach is complicated by the fungus’s resistance patterns. Echinocandins are the initial recommended treatment for adults and children over two months of age with C. auris infections. This class of drugs is preferred because most C. auris strains found in the United States remain susceptible to them.
However, the increasing number of echinocandin-resistant and pan-resistant cases presents a challenge, as some strains are resistant to all three major classes of antifungals. For these difficult-to-treat infections, healthcare providers may consider using liposomal amphotericin B or combination antifungal therapy. Susceptibility testing is crucial to guide treatment decisions, determining which antifungal drugs will be most effective.
Treatment is only for active clinical infections, not for colonization. Patients with C. auris colonization can carry the fungus for extended periods, potentially indefinitely, without becoming ill. Medical consultation is essential for proper diagnosis and management of C. auris infections.
Preventing Further Spread
Preventing the spread of Candida auris involves a comprehensive approach focused on infection control measures. Hand hygiene is a fundamental practice, with healthcare providers encouraged to use alcohol-based hand sanitizer unless hands are visibly soiled, in which case soap and water should be used. Proper hand hygiene is essential before and after patient contact and after removing gloves.
Isolation precautions are also important in healthcare settings to limit transmission. Patients with C. auris infection or colonization should be placed in a private room, or cohorted with other C. auris-positive patients, and contact precautions should be consistently followed. Dedicated medical equipment should be used for infected patients whenever possible, and shared equipment must be thoroughly cleaned and disinfected after each use.
Surveillance and screening help identify new cases and track the spread of C. auris to contain outbreaks, including notifying public health departments. Healthcare personnel training and auditing adherence to infection control practices are important to ensure consistent application of these preventative strategies.