This New Fungus Is A Problem And Climate Change Is The Reason Why

What is Candida auris?

 First identified in Asia in 2009, C. auris is now found on four continents. In the US, it was initially only found in certain hospitals, nursing homes, and long-term healthcare settings in a few major hubs like New York City and Chicago, Roberts said. But a recent CDC study showed that it has now been found in more than half of US states.

This type of yeast can colonize your skin and gut, among other areas. It’s spread by close contact with someone who is infected or colonized with the fungus. The person does not need to have symptoms to be infectious, Roberts said. It can also spread through contaminated surfaces, where it can survive for weeks, according to the CDC.

 The only treatment is intravenous antifungal medications, but the recent CDC report, published in Annals of Internal Medicine, documented a tripling in the number of cases resistant to echinocandins, the class of drug that is typically the first choice for this type of infection. 

Some isolates are resistant to three major classes of available antifungal medications and most are resistant to fluconazole (Diflucan), one of the most common antifungals out there, Roberts said.

In absolute numbers, though, drug-resistant cases are still relatively uncommon.

Who’s at risk?

Many times, C. auris doesn’t cause any infection, Roberts said. But not always.

“Those at highest risk for severe infections with C. auris include people who are already sick from other health conditions and are immunocompromised, have long or frequent stays in healthcare facilities, or have lines or tubes that go into their body, such as central venous catheters, feeding tubes, breathing tubes,” Madad said. “The infection can prove deadly for 30% to 60% of those infected with invasive C. auris.”

Why it’s spreading

A warming climate is likely a major reason for the rapid rise in C. auris around the world. 

“A major hypothesis as to why this wasn’t seen before is that this fungus evolved with climate change,” Roberts said. “It is better able to withstand higher temperatures compared to similar types of fungi.”

But the CDC has also identified other reasons for the increase in cases, including higher screening rates, a healthcare system that’s under pressure due to the COVID-19 pandemic, and insufficient infection control procedures.

Healthcare facilities and public health experts are at the forefront of fighting the germ and must increase surveillance and take steps to control infections in general, the experts we talked to said.

The most important steps people can take to avoid the fungus is to practice good hand hygiene, aka hand washing, especially in healthcare settings, Roberts said.

Other emerging threats

Roberts predicted that we’ll see more pathogens emerge as global temperatures continue to rise. “Climate change is going to increase the risk of new fungal threats, and Candida auris is a great example,” he said. “I suspect over time we will see both rising cases of Candida auris and new species emerge.”

The World Health Organization released its first “fungal priority list” late last year, which put pathogens into “critical,” “high” and “medium priority” categories. Candida auris is on the critical list, as are Candida albicans (also a yeast), Cryptococcus neoformans (which can infect the lungs and central nervous system), and Aspergillus fumigatus (which has developed resistance to certain drugs).

“While C. auris outbreaks are not indicative of [a scenario like] the HBO hit show The Last of Us — and far from it — the reality is, as climate change persists, its impact on infectious diseases … will only grow,” Madad said.