A closer look at Candida auris

Candida auris (C. auris) has been spreading in more than half of the states in the U.S. following a dramatic 95% increase in cases in 2021, according to the country’s Centres for Disease Control and Prevention in the first quarter of 2023. In Hong Kong, up to August this year, there have been more than 500 cases since the first case was diagnosed in 2019. Most cases detected in Hong Kong are carriers without symptoms, with patients ranging aged 20 to 101. These figures indicate that C. auris is a global health issue requiring urgent action.

Q1: What is C. auris?

C. auris is a fungal infection caused by a yeast called Candida which is 90% resistant to the antifungal medication fluconazole and amphotericin B. It spreads easily among patients in healthcare facilities. It can survive for months and common disinfectants may not be effective against C. auris. C. auris was difficult to be identified and was easily misidentified as other Candida species by standard laboratory tests. Around 10% of carriers develop an invasive infection and the mortality rate can be as high as 30% to 60%. It was first discovered in Japan in 2009.

Q2: Who are most susceptible to C. auris infection?

Patients with immunocompromised conditions, chronic renal disease, or diabetes mellitus, as well as long-stay patients in intensive care unit and haemodialysis patients, are at higher risk of C. auris. People given antibacterial and antifungal treatment, have recently undergone vascular and abdominal surgery or treated with invasive medical devices such as central venous catheters, post-operative drains, and urinary catheters are also at higher risk of infection.

Q3: How is it transmitted?

C. auris can be transmitted through contact with contaminated surfaces or equipment, or from physical contact with a person who is infected or colonised. Meticulous attention to infection control measures, including good hand hygiene and environmental hygiene, is important to prevent the spread of infection.

Q4: What are the clinical features?

C. auris can be found in the armpits, groin, nostrils, external ear canals, wounds and urethra. People can be colonised with C. auris without symptoms. However, some colonised patients may develop C. auris infection such as wound infection, urinary tract infection or even bloodstream infection.