Since it was first isolated from the ear of a Japanese woman with otitis in 2009, the fungus Candida auris (C. auris) has been appearing in different parts of the world. This mysterious germ, which colonizes people with weakened immune systems, it spreads silently all over the world. Now, the U.S. Centers for Disease Control and Prevention (CDC) has reported two sprouts in its territory: one in a nursing home for seriously ill patients in the District of Columbia (DC) and another involving two hospitals in the Dallas (Texas) area that share patients.
The CDC considers this fungus a “Serious threat” to global health because it is often multidrug resistantSome strains are even resistant to all three classes of antifungals available; it is difficult to identify with standard laboratory methods and may go unnoticed without specific technology. It has caused outbreaks in healthcare settings, so it is important to quickly diagnose in a hospitalized patient to prevent its spread.
Colonization of the skin with C. auris allows spread and leads to invasive infections, including of the bloodstream, in 5% to 10% of colonized patients. There are three main classes of antifungal medications for treating invasive infections: azoles, polienos y equinocandinas. Approximately 85% of C. auris isolates in the United States are resistant to azoles, 33% to amphotericin B, and 1% to echinocandins. Echinocandins are therefore critical for the treatment of C. auris infections. and are recommended as first-line therapy for most invasive Candida infections. Echinocandin resistance is a worrisome clinical and public health threat, particularly when combined with resistance to azole and amphotericin B (pan-resistance).
Although cases are rare, pan-resistant strains of C. auris have been previously reported in the United States and other countries. Three cases of pan-resistant C. auris reported in New York developed resistance after treatment with echinocandin and lacked epidemiological links or common medical care, suggesting that the resistance was due to antifungal pressure rather than person-to-person transmission. However, since January 2021, the Antibiotic Resistance Laboratory Network has detected independent clusters of pan-resistant or echinocandin-resistant cases in Texas and the District of Columbia (DC). Each group had common healthcare encounters and no known previous exposure to echinocandin, suggesting the transmission of pan-resistant and resistant strains to echinocandin for the first time in the United States.
Between 101 cases of C. auris in DC During January-April 2021, three had insulation that was pan-resistant. All resistant isolates were identified by skin colonization examination in a critically ill nursing home, including some requiring mechanical ventilation.
Between the 22 cases of C. auris in Texas during the same period, two were pan-resistant and five resistant to both echinocandins and fluconazole. These seven cases were identified in two health centers that share patients in the same city; two patients were in a long-term acute care hospital, three in a short-term acute care hospital, and two in both facilities. Among these cases, four were identified by colonization screening and three by clinical isolates (two blood isolates and one wound isolate).
No known epidemiological links were identified between the Texas and DC groups. No patient with pan-resistant or echinocandin-resistant strains in either group had received echinocandins prior to collection of C. auris samples. The 30-day mortality in both outbreaks combined was 30%, but the relative contribution of C. auris was unclear.
These two simultaneous and independent groups of antifungal-resistant C. auris cases in patients with overlapping exposures from hospital care and no prior echinocandin use provide the first evidence to suggest that Echinocandin-resistant or pan-resistant C. auris strains may have been transmitted in U.S. healthcare settings.
The CDC cautions that surveillance, public health reporting, and infection control measures are critical to containing further spread. «Doctors should consider the possibility of performing early antifungal susceptibility testing in patients with C. auris infection, especially in those with treatment failure. Data on the most appropriate therapy for pan-resistant infections are lacking. Investigational and combination antifungal treatments can be considered, but the evidence in clinical settings is limited. More information is needed to evaluate patient outcomes and identify appropriate treatment for C. auris cases with resistance to pan resistance or resistance to echinocandins, ”the CDC report concludes.