As COVID-19 hospitalizations continue to surge around the world, another dangerous infection may also be sickening patients: a drug-resistant superbug called Candida auris, National Geographic reported (opens in new tab).
The superbug is a yeast that can infect the ears and open wounds, and it can also enter the bloodstream to trigger severe infection throughout the body, according to the U.S. Centers for Disease Control and Prevention (CDC). The yeast clings to surfaces and spreads easily in health care settings, especially among patients with catheters or other tubes that enter their bodies.
Now, early data hints that the influx of COVID-19 patients in hospitals may also be driving a surge of C. auris cases, according to the National Geographic report. Notably, the United States has already reported 1,272 cases of the fungal infection this year, according to the CDC — that's about a 400% increase over the number of cases reported in all of 2018, the most recent year with available data. The number of cases in 2020 may be even higher than reported, given that the ongoing pandemic has disrupted surveillance systems used to track the fungus's spread. Other kinds of fungi in the Candida genus closely resemble C. auris, so doctors can identify the yeast only by using a specialized laboratory test.
"Unfortunately, there have been places where we've seen a resurgence of C. auris," Dr. Tom Chiller, head of the mycotic diseases branch at the CDC, told National Geographic. "We've also seen it get into some of the acute care hospitals and also into some COVID-19 units … the concern there is that once it sets up shop in a place, it's hard to get rid of."
According to the CDC, "patients can remain colonized with C. auris for a long time," meaning the fungus can remain on their skin without necessarily causing overt symptoms, "and C. auris can persist on surfaces in healthcare environments." The superbug can also be notoriously difficult to treat. The C. auris yeast comes in several variants that show resistance to different classes of antibiotic drugs; in particular, many variants studied show resistance to the common antifungal fluconazole, and several show resistance to amphotericin B, a second-line antifungal drug that can be given if an initial antibiotic fails, National Geographic reported. Due to drug-resistance, doctors must sometimes resort to treating patients with third-line drugs if a second-line treatment also fails.
Most known variants of C. auris can be treated with third-line antifungals called echinocandins, but these treatments aren't readily available in all countries and some variants of the yeast show resistance to all three classes of antifungals, the CDC notes. Since the yeast was identified in 2009, a few thousand cases have been reported around the world; about 30% to 60% of people infected with the fungus worldwide have died, although many of these people had other serious illnesses, simultaneously, according to the agency.
Dr. Anuradha Chowdhary, a professor of medical mycology at Vallabhbhai Patel Chest Institute at the University of Delhi, told National Geographic that COVID-19 patients should be regularly screened for C. auris, in order to accurately track rates of infection and identify which antibiotic treatments, if any, might help affected patients recover.
"If we don't identify it, then we don't know if a patient is dying of COVID-19 or another infection," Chowdhary said. But "if it's resistant to drugs, how will we treat it?" she added.
If a given variant of C. auris resists all three classes of antifungal medication, "multiple classes of antifungals at high doses may be required to treat the infection," but this treatment would be a last resort, the CDC notes. Research suggests that using several classes of antifungal at the same time may have an additive effect and help overpower the yeast's resistance to individual drugs, although this still needs to be confirmed with more data.
You can learn more about C. auris at National Geographic (opens in new tab).
Originally published on Live Science.