What is Candida auris infection?


At the end of March 2023, major media outlets in some countries around the world reported that an unfamiliar disease was spreading in the United States - Candida auris infection.

Recently, researchers from the U.S. Centers for Disease Control and Prevention (CDC) published an article in the Annals of Internal Medicine, saying that Candida Auris, a drug-resistant and lethal bacterium, is spreading at an alarming rate in medical institutions across the United States, posing a public health threat. Cases of infection have now been detected in more than half of the states in the United States. People with weakened immune systems or who use medical devices such as respirators can become seriously ill or die if they become ill. According to the CDC, nearly half of patients with Candida auris infection die within 90 days, with a case fatality rate of up to 60%.

Many people are concerned about such a high-risk, fatal bacterial infection. The case fatality rate of the disease is thought to be close to that of Ebola virus disease (also known as Ebola haemorrhagic fever). So, what exactly is Candida auris?

The case fatality rate of Ebola virus disease is 25%~90%, and its causative agent is a virus. According to the biological classification, Candida auris belongs to the fungal kingdom and is a fungus of the genus Candida, which belongs to two species with the Ebola virus. The Auris in the English name of Candida auris comes from the Latin word for "ear". In 2009, Japanese scientists isolated the fungus from a patient's ear canal for the first time.

Candida is a fungus that occurs widely in the natural environment and is commonly found in the mouth, digestive tract, skin, and vagina in women. Candida auris is one of the few fungi in Candida that can infect humans, and can invade the bloodstream and infect the heart, brain and other vital organs of the human body. Normally, Candida auris mainly infects people with weakened or immunosuppressed immune systems, such as the frail elderly, newborns, diabetic patients, intensive care unit patients and postoperative patients, etc., which can cause invasive candidiasis, such as candidemia, pericarditis, urinary tract infection and pneumonia. However, healthy people with normal immunity have a lower risk of C. auris infection.

Candida auris has a characteristic of being able to survive long periods of time on the skin surfaces of patients, healthcare workers, and hospital facilities. In addition, Candida auris has a high mortality rate, difficult diagnosis of infection, and multi-drug resistance, so it is called a "super fungus".

At present, the CDC has put Candida auris on the list of "urgent threats", the biological origin of Candida auris is not yet known, and the fungus has not been found in the natural environment. For this reason, researchers speculate that Candida auris is a new species that has evolved in recent decades and can quickly adapt and inhabit humans.

Genome sequencing showed that Candida auris was genetically embodied in having genetic segregation of fungi on different continents and subcontinents, including branches of East Asia, South Asia, and South America.