Since its discovery in 2009, Candida auris has emerged as a serious threat to human health. While it can colonize the skin of healthy people without causing symptoms, the fungus also invades the bloodstreams and wounds of vulnerable people, often in health care settings, and according to the Centers for Disease Control and Prevention (CDC), more than one-third of people with these invasive infections die. Last week, the CDC announced more bad news about C. auris: what the agency says is the first evidence that highly drug-resistant strains of the fungus are spreading from person to person. 

“If you wanted to conjure up a nightmare scenario for a drug-resistant pathogen, this would be it,” Cornelius Clancy, an infectious diseases doctor at the VA Pittsburgh Health Care System, tells The New York Times. “An untreatable fungus infection would pose a grave threat to the immunocompromised, transplant recipients and critically ill patients in the I.C.U.”  

According to the CDC, there are three classes of antifungals used to treat invasive infections: azoles, polyenes, and echinocandins. While resistance to azoles and polyenes is relatively common, only about 1 percent of infections are resistant to echinocandins, making them a go-to therapy for Candida infections that aren’t susceptible to other drugs. Fungal strains that can withstand treatment with all three classes are known as pan-resistant. 

Pan-resistant strains of C. auris have been detected before, the CDC notes, but only in patients who had been treated with echinocandins. The agency says that earlier this year, pan-resistant strains were found in patients in a long-term care facility in Washington, DC and in a long-term care facility and hospital in Texas that share patients; none of those patients had received the antifungal. The CDC says 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.” 

Meghan Lyman, a medical officer who coauthored the CDC report, tells the Times, “The concerning thing is that the patients at risk are no longer the small population of people who have infections and are already being treated with these medications.”  

“We need to do a better job at surveillance and infection control, especially in places where we put patients in group settings,” Michael Phillips, an epidemiologist at NYU/Langone Health, tells the newspaper. “Candida auris is something we should be concerned about, but we can’t lose sight of the bigger picture because there are a lot of other drug-resistant bugs out there we should be worried about.” 

Indeed, a report published earlier this month in Open Forum Infectious Diseases found that transmission of another type of drug-resistant pathogen—pneumonia-causing bacteria—is already common among pediatric patients treated at one hospital in Bangladesh. The authors of that study examined the records of more than 4,000 children hospitalized with pneumonia between 2014 and 2017, and found that of the 108 who tested positive for bacteria in their blood, 20 had infections that were resistant to all four routinely used antibiotics.  

“In the U.S. I see a lot on antibiotic resistance in patients who have been in the hospital for weeks or months with chronic illness, but the fact that these are kids coming in from the community with these severe resistant infections is very worrying,” coauthor Jason Harris of the Massachusetts General Hospital for Children tells Medical News Today. He adds, “If we don’t do anything to address it now, these bacteria will continue to spread, and they will inevitably be the new normal everywhere.”