The Centers for Disease Control and Prevention (CDC) issued a warning on Monday stating that cases of the drug-resistant fungus Candida auris are increasing at an “alarming” pace in healthcare facilities across the country. This comes after reports revealed that the number of infected patients have nearly doubled in 2021.
After the first reported cases of Candida auris in the U.S. in 2016, only a handful of patients were reported to the CDC each year for several years. However, according to new CDC data published in the Annals of Internal Medicine, the number of cases has started to surge in recent years. In 2021, the number of cases increased by 95%, rising from 756 in 2020 to 1,471.
Early estimates suggest that there were at least 2,377 cases in 2022. Currently, Candida auris patients have been reported in thirty states and the District of Columbia.
Dr. Meghan Lyman, the CDC epidemiologist and the lead author of the report, stated that the number of cases is still on the rise, and the previously observed issues have not been resolved. “We’re continuing to see the number of cases increase. So what we saw before is continuing. It didn’t stop.”
Candida auris is a type of yeast that typically doesn’t cause any symptoms in healthy individuals. However, it can pose a serious risk to patients who are already weakened by other medical conditions, leading to invasive complications as it spreads throughout the body. Many cases have occurred in hospitals and nursing homes.
Almost all Candida auris samples tested are resistant to at least one type of antifungal medication. One out of three patients with invasive infections die. However, it can be challenging to determine the exact role the fungus played in some of these vulnerable patients, according to Dr. Lyman, the report’s lead author. Even those who survive invasive infections may remain “colonized” with Candida auris for years after treatment.
“We still have a lot to learn about colonization patterns. Although treatment may help control the infection, we don’t have evidence that it completely eradicates Candida auris from the body,” said Dr. Lyman.
Monday’s report is the latest reminder of the growing threat of a range of drug-resistant pathogens. The CDC had already placed Candida auris in the highest “urgent” threat category in a 2019 report on emerging drug-resistant pathogens nationwide. In 2022, the CDC added Candida auris to the list of drug-resistant infections that had increased significantly following the COVID-19 pandemic.
Other countries have also reported new or increasing cases of Candida auris infections in recent years.
Although it can be challenging to determine the precise effect of the COVID-19 pandemic on this trend, Dr. Lyman, who works in the CDC’s fungal diseases branch, which concentrates on drug resistance in healthcare settings, referred to investigations that revealed some links.
For example, one CDC report studied a COVID-19 wing outbreak in a Florida hospital in 2020, after admission screening and certain precautions were suspended during the pandemic.
“We continue to see challenges with infection control, so it’s not all resolved now that COVID’s not here. This is kind of a cautionary tale. But I think it highlights some things that may have been there before that got worse during COVID,” said Lyman.
Candida auris was ranked by the World Health Organization as one of the most severe fungal threats to public health due to its potential to harm vulnerable patients and the difficulties doctors face in managing and halting drug-resistant outbreaks.
According to data from the CDC’s network of antimicrobial-resistant labs, almost all of the Candida auris samples tested are resistant to at least one class of antifungal treatment. Only a small percentage of tested cases demonstrated resistance to echinocandin, the primary therapy for treating Candida auris infections.
Nonetheless, Lyman’s report highlights a gradual rise in cases of “pan-resistant” fungal infections, which are resistant to all available medications. Health authorities recorded outbreaks in Texas and D.C. in 2021, indicating that resistant infections are spreading, even in patients who never received echinocandin treatment.
Lyman stated that hospitals and nursing homes have methods for combating Candida auris transmission, such as screening for cases and taking extra steps to isolate infected patients. The ability of laboratories to detect and diagnose cases has improved, especially with the knowledge of strategies to reduce transmission between patients.
She added, “While it may not be realistic for some of these locations to never see a case again, there is still a lot that can be done to prevent spread.”