What is the drug-resistant superbug fungus? All about Candida auris

Share on Pinterest

C. auris is a type of fungus or yeast that is a newly emerging health concern. It is multidrug-resistant, meaning it is resistant to many antifungal drugs that usually treat fungal infections.

The fungus first became apparent to researchers in 2009 and has since been causing outbreaks in healthcare settings worldwide.

C. auris can cause severe infections in hospitalized people, and in some cases, it can be life threatening.

C. auris is usually resistant to multiple types of antifungal drugs. There are currently three different classes of antifungal drugs available, and some strains of C. auris are resistant to all of these.

The fungus is also difficult to identify. Regular laboratory methods are not always effective at identifying C. auris, which can lead to misidentification, making it more difficult to manage and treat.

C. auris can survive for long periods on the skin and surfaces, which means it can pass more easily from person to person.

Outbreaks of this fungus have occurred in healthcare facilities and can cause severe illness in hospitalized people. Invasive infections of C. auris, which affect the bloodstream, heart, or brain, can be fatal.

C. auris can live on human skin for long periods and on surfaces for several weeks. It can also survive some common disinfectants within healthcare settings. This means the fungus can pass easily from person to person or through touching contaminated surfaces.

People who may have the highest risk of C. auris infection include those with:

• long-term hospitalization or stays in healthcare facilities such as nursing homes
• breathing or feeding tubes, central venous catheters, or other tubes and lines going into their body
• a recent surgery
• diabetes
• experience of taking broad-spectrum antibiotic and antifungal medications

Symptoms of infection with C. auris may vary depending on the area of the infection, such as the ear, a wound, or the bloodstream.

According to the Centers for Disease Control and Prevention (CDC), C. auris invasive infections usually affect people who already have an existing medical condition, which may mask symptoms of the fungal infection.

The most common symptoms of a C. auris infection are fever and chills that do not get better with antibiotic treatment.

There are currently three main drug classes of antifungals, which healthcare professionals use to treat fungal infections:

• azoles, such as fluconazole
• polyenes, such as amphotericin B
• echinocandins, such as anidulafungin

According to a 2021 CDC report, in the United States, around 85% of C. auris is resistant to azoles, around 33% is resistant to amphotericin B, and 1% is resistant to echinocandins.

This means echinocandins are usually the first-line treatment for invasive Candida infections, including C. auris.

The report also notes researchers have identified some strains of C. auris that are pan-resistant, meaning they are resistant to all three classes of antifungal drugs.

Learn more about antifungal drugs.

Currently, the only way to diagnose a C. auris infection is through laboratory testing of blood or other body fluids.

However, it is difficult to detect this fungus in a laboratory with standard equipment, so laboratories require specialized equipment to identify C. auris strains.

Learn about blood tests.

Invasive Candida infections are serious infections that can affect parts of the body, such as the:

• bloodstream
• heart
• brain
• eyes
• bones

According to a 2021 CDC report, C. auris present on the skin can spread and lead to invasive infections. Bloodstream infections affect 5–10% of people who carry the fungus.

Invasive infections of C. auris can be life threatening. It is unclear yet whether invasive infections of this fungus are more likely to be fatal compared with other types of invasive Candida infections.

According to data involving a small number of people with C. auris infections, 30–60% of these individuals have died. However, many of these people already had serious medical conditions, which increased their risk of dying.

Within healthcare settings, C. auris can spread through contact with contaminated surfaces or from person to person.

The CDC suggests the following precautions for healthcare settings to reduce the spread of this fungus:

• maintain good hand hygiene practices, such as frequent handwashing and use of alcohol-based hand sanitizers
• placing people with C. auris in the same section of the healthcare facility or in single rooms
• thorough, daily cleaning with disinfection of surfaces, rooms, and equipment in healthcare settings

The CDC states that the risk of C. auris outside of healthcare facilities is low but recommends the following hygiene tips:

• maintain good hand hygiene, which includes regularly washing the hands with soap and water or using an alcohol-based hand sanitizer
• if caring for a person with C. auris, use disposable gloves if carrying out wound care or coming into contact with bodily fluids
• before entering a healthcare facility, a person should inform healthcare providers if they have come into contact with someone with a C. auris infection

According to the CDC, although C. auris is becoming more common, it is still rare in the United States.

In most cases, doctors can treat this fungal infection with echinocandins, a type of antifungal drug that strains of C. auris may have the least resistance to.

If the strain of C. auris is resistant to all types of antifungals, doctors may use high doses of multiple antifungal drugs to treat the infection.

C. auris infections are rare in healthy people or outside of healthcare facilities.

C. auris is a fungus that has recently become more common in healthcare settings. It can survive on the skin and surfaces for long periods, meaning it can spread easily within healthcare facilities.

C. auris can lead to invasive infections, affecting areas of the body such as the bloodstream, brain, or heart. These infections may be life threatening in hospitalized people who have existing serious health conditions.

In most cases, antifungal drugs, in particular echinocandins, can still treat C. auris infections. For highly resistant strains of the fungus, people may require treatment with high doses of multiple antifungals.