Judy Stone, MD
July 30, 2021
The CDC has reported two clusters of Candida auris infections resistant to all anti-fungal medications in long-term care facilities in 2021. Because these pan-resistant infections occurred without any exposure to antifungal drugs, the cases are even more worrisome. These clusters are the first time such nosocomial transmission has been detected.
In the District of Columbia, three pan-resistant isolates were discovered through screening for skin colonization with resistant organisms at a long-term acute care facility (LTAC) that cares for patients who are seriously ill, often on mechanical ventilation.
In Texas, the resistant organisms were found both by screening and in specimens from ill patients at an LTAC and a short-term acute care hospital that share patients. Two were pan-resistant, and five others were resistant to fluconazole and echinocandins.
These clusters occurred simultaneously and independently of each other; there were no links between the two institutions.
Colonization of skin with C auris can lead to invasive infections in 5% to 10% of affected patients. Routine skin surveillance cultures are not commonly done for candida, although perirectal cultures for vancomycin-resistant enterococci (VRE) and nasal swabs for MRSA have been done for years. Some areas, like Los Angeles, have recommended screening for C auris in high-risk patients — defined as those who were on a ventilator or had a tracheostomy admitted from an LTAC or skilled nursing facility in Los Angeles county, New York, New Jersey, or Illinois.
In the past, about 85% of C auris isolates in the US have been resistant to azoles (eg, fluconazole), 33% to amphotericin B, and 1% to echinocandins. Because of generally strong susceptibility, an echinocandin such as micafungin or caspofungin has been the drug of choice for an invasive candida infection.
C auris is particularly difficult to deal with for several reasons. First, it can continue to live in the environment, on both dry or moist surfaces, for up to 2 weeks. Outbreaks have occurred both from hand (person-to-person) transmission or via inanimate surfaces that have become contaminated. Equally troublesome is that people become colonized with the yeast indefinitely.
Meghan Lyman, MD, of the fungal diseases branch of the CDC's National Center for Emerging and Zoonotic Infectious Diseases, told Medscape Medical News that facilities might be slow in recognizing the problem and in identifying the organism. "We encounter problems in noninvasive specimens, especially urine," Lyman said.
"Sometimes ... they consider candida [to represent] colonization so they will often not speciate it." She emphasized the need for facilities that care for ventilated patients to consider screening. "Higher priority ... are places in areas where there's a lot of C auris transmission or in nearby areas that are likely to get introductions." Even those that do speciate may have difficulty identifying C auris.
Further, Lyman stressed "the importance of antifungal susceptibility testing and testing for resistance. Because that's also something that's not widely available at all hospitals and clinical labs ... you can send it to the [CDC's] antimicrobial resistance lab network" for testing.
COVID-19 has brought particular challenges. Rodney E. Rohde, PhD, MS, professor & chair, Clinical Lab Science Program, Texas State University, San Marcos, told Medscape that he is worried about all the steroids and broad-spectrum antibiotics patients receive.
They're "being given medical interventions, whether it's ventilators or ECMO or IVs or central lines or catheters for UTIs and you're creating highways, right for something that may be right there," said Rohde, who was not involved in the CDC study. "It's a perfect storm, not just for C auris, but I worry about bacterial resistance agents, too, like MRSA and so forth, having kind of a spike in those types of infections with COVID. So, it's kind of a doubly dangerous time, I think."
Multiresistant bacteria are a major health problem, causing illnesses in 2.8 million people annually in the US, and causing about 35,000 deaths.
Rohde raised another, rarely mentioned concern. "We're in crisis mode. People are leaving our field more than they ever had before. The Medical Laboratory is being decimated because people have burned out after these past 14 months. And so I worry just about competent medical laboratory professionals that are on board to deal with these types of other crises that are popping up within hospitals and long-term care facilities. It kind of keeps me awake."
Rohde and Lyman shared their concern that COVID caused a decrease in screening for other infections and drug-resistant organisms. Bare-bones staffing and shortages of personal protective equipment have likely fueled the spread of these infections as well.
In an outbreak of C auris in a Florida hospital's COVID unit in 2020, 35 of 67 patients became colonized, and 6 became ill. The epidemiologists investigating thought that contaminated gowns or gloves, computers, and other equipment were likely sources of transmission.
Low pay, especially in nursing homes, is another problem Rohde mentioned. It's an additional problem in both acute and long-term care that "some of the lowest-paid people are the environmental services people, and so the turnover is crazy." Yet, we rely on them to keep everyone safe. He added that, in addition to pay, he "tries to give them the appreciation and the recognition that they really deserve."
There are a few specific measures that can be taken to protect patients. Lyman concluded, "The best way is identifying cases and really ensuring good infection control to prevent the spread." It's back to basics — limiting broad-spectrum antibiotics and invasive medical devices, and especially good handwashing and thorough cleaning.
Lyman and Rohde have disclosed no relevant financial relationships.