Candida auris is an emerging fungus that poses a serious global health threat, particularly within healthcare environments. First identified in Japan in 2009, this yeast is concerning because it can cause severe, invasive infections and is often resistant to multiple classes of antifungal medications commonly used to treat other Candida infections. The fungus is known to spread easily among already sick patients in hospitals and long-term care facilities. The ability of C. auris to persist on surfaces for extended periods and its multidrug resistance make its identification and control a significant public health challenge.
Why Identifying Symptoms is Difficult
The symptoms of an infection caused by C. auris are not easily recognizable, which complicates early clinical detection. This difficulty arises because the signs of a C. auris infection are non-specific and closely resemble those caused by more common bacterial or other fungal pathogens. Patients often already have severe underlying medical conditions, and the symptoms of the fungal infection can be masked by their existing illnesses.
A patient may present with general signs of systemic infection, such as a high fever and chills, which are common to many different types of infection. These symptoms frequently fail to improve even after a patient has been given broad-spectrum antibiotics to treat a suspected bacterial infection. This lack of response to standard treatment is often the first clue that a non-bacterial pathogen, such as C. auris, may be the cause of the illness. The nonspecific nature of the symptoms means a definitive diagnosis cannot be made based on clinical presentation alone.
Specific Manifestations of Infection
The most serious presentation is an invasive bloodstream infection, known as candidemia, which occurs when the fungus enters the blood and can spread throughout the body. Symptoms of candidemia include persistent fever and chills that do not resolve with typical antibiotic therapy, often accompanied by low blood pressure and a rapid heart rate.
C. auris can also cause localized infections in various body sites, each with its own specific set of signs. In the ear, the infection may present with pain, a feeling of fullness, muffled hearing, and unusual ear drainage. When the fungus infects a wound, symptoms may include increased pain, redness, warmth around the site, and delayed healing. The fungus is also known to cause urinary tract infections, particularly in catheterized patients.
Who is Most Vulnerable to Infection
Healthy individuals with intact immune systems are not at risk for developing an invasive C. auris infection. The population most vulnerable are patients who are severely ill and receiving complex medical care in a healthcare setting. This includes individuals with prolonged stays in intensive care units or long-term care facilities.
A significant risk factor involves the presence of indwelling medical devices, which create a direct pathway for the fungus to enter the body. These devices include central venous catheters, breathing tubes, feeding tubes, and urinary catheters. Patients with underlying health issues that compromise the immune system, such as diabetes or blood cancers, are also at an increased risk. The prolonged or frequent use of broad-spectrum antibiotics or antifungal medications can also disrupt the body’s natural microflora, further increasing susceptibility to C. auris infection.
Testing and Confirmed Diagnosis
A confirmed diagnosis of C. auris infection requires specialized laboratory testing. Samples are collected from affected sites, such as blood, urine, or wound fluid, or from external body sites like the axilla and groin for colonization screening. The fungus cannot be reliably identified using standard laboratory methods because its physical characteristics are not distinct enough to differentiate it from other Candida species under a microscope.
Specialized techniques are necessary to accurately confirm the presence of C. auris and avoid misidentification, which can delay appropriate treatment. The most reliable method for definitive identification involves Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS). Molecular methods, such as real-time Polymerase Chain Reaction (PCR), are also highly accurate and are the preferred technique for rapidly detecting colonization in surveillance screening. Accurate and timely identification is important because it dictates the need for specific antifungal treatments, as many strains are resistant to common drugs.