Investigations of Pan-Resistant C auris Cases After Antifungal Treatment

The Centers for Disease Control and Prevention (CDC) summarized investigations into 3 cases of pan-resistant Candida auris infections in New York. The report, published in Morbidity and Mortality Weekly Report, stated that while extensive investigation failed to find transmission of the resistant isolates to other patients or the environment, the emergence of pan-resistance is concerning.

C auris is a fungal yeast known to cause outbreaks in healthcare settings around the world. Furthermore, cases that are resistant to all 3 commonly prescribed antifungal drugs, so-called pan-resistant cases, have also been reported in multiple countries. In the United States, New York has the highest number of identified cases as of October 31, 2019. Since June 2019, a total of 801 patients were identified in New York based on clinical cultures or swabs of skin or nares obtained to detect asymptomatic colonization and 3 cases were deemed pan-resistant.

All 3 pan-resistant cases occurred in patients with underlying comorbidities and the resistant C auris developed after receipt of antifungal medications. All 3 patients demonstrated initial sensitivity to treatment with echinocandins, which their infections subsequently became resistant to. None of the patients had any known recent domestic or foreign travel and there was no evidence to suggest they transmitted the resistant infection to any other patients or the environment.

The first 2 cases occurred in 2017 and 2018 in individuals aged >50 years, both of whom were residing in long-term care facilities. There was no epidemiologic link between the cases. After the identification of these 2 cases, a retrospective review of all New York isolates was conducted that identified a third patient with pan-resistant isolates from 2017. This patient was also aged >50 years, had multiple comorbidities, and had a prolonged hospital and long-term care admission at facilities in a different borough from the other 2 cases.

According to the investigators, the incidence of pan-resistant C auris in New York remains rare. However, the report concluded that a need for surveillance and susceptibility testing of all isolates, especially after treatment with antifungals, remains. “The occurrence of these cases underscores the public health importance of surveillance for C. auris, the need for prudent antifungal prescribing, and the importance of conducting susceptibility testing on all clinical isolates, including serial isolates from individual patients, especially those treated with echinocandin medications.”

Reference

Ostrowsky B, Greenko J, Adams E, et al. Candida auris isolates resistant to three classes of antifungal medications – New York, 2019. MMWR Morb Mortal Wkly Rep. 2020;10:6-9.

This article originally appeared on Infectious Disease Advisor