Superbug Fungus Candida Auris Explained As CDC Warns of U.S. Cases: 'Global Health Threat'

Researchers have discovered transmission of a type of drug-resistant fungal infection in Texas and Washington, D.C. for the first time in the U.S.

The patients had been infected with Candida auris, an emerging fungus that is highly transmissible and, according to the Centers for Disease Control and Prevention (CDC), "presents a serious global health threat."

C. auris has appeared in the country only recently, and researchers are still studying it to find out more about how it is spread. Infections have occurred in over 30 countries worldwide.

What is known is that it mainly affects patients who already have medical problems and often occurs in people who frequently visit hospitals or live in nursing homes. People who have tubes that go into their body for medical reasons are also at risk.

C. auris also more likely to affect patients with weakened immune systems and doesn't usually occur in healthy people.

Symptoms can vary greatly depending on which part of the body may be affected. C. auris can cause many different types of infection including a bloodstream, wound, or ear infection. Symptoms may not be noticeable because patients often are already sick with some other illness.

C. auris can kill patients, but doctors aren't sure if it is more deadly than other Candida species.

Limited information suggests that 30 to 60 percent of people with C. auris infections have died—though many of these patients already had other serious illnesses.

While most C. auris infections are treatable with antifungal medications called echinocandins, the fungus is often resistant to multiple drugs and in some cases is resistant to all three available classes of antifungal medications.

The CDC states it is concerned about C. auris because of its drug resistance, plus the fact that it is difficult to identify without specific technology and because it causes outbreaks in healthcare settings.

While more research is needed, the fungus can spread through contact with contaminated surfaces or from person to person.

Most C. auris isolates in the U.S.—around 85 percent—are resistant to the class of antifungal drug called azoles. Around 33 percent are resistant to the antifungal drug amphotericin B, and around 1 percent are resistant to echinocandins.

As such, echinocandin resistance in C. auris is concerning, but this is what has occurred in five U.S. cases reported by the Antibiotic Resistance Laboratory Network between January and April 2021. Three of the cases were in D.C., and two in Texas.

The CDC outlined the cases in its Morbidity and Mortality Weekly Report published July 23. The report's authors wrote that the cases "provide the first evidence suggesting that pan- or echinocandin-resistant C. auris strains might have been transmitted in U.S. health care settings."

They also said: "Surveillance, public health reporting, and infection control measures are critical to containing further spread."

Petri dish
A stock photo shows a scientist swabbing a petri dish. Research is ongoing to find out more about Candida auris. yacobchuk/Getty