Drug-Resistant Candida Auris Fungus Spreading in Hospitals Globally and in Israel

Candida auris, a drug-resistant fungus, is spreading in hospitals and nursing facilities worldwide, including in Israel. This fungus can be carried on the skin asymptomatically, with negative test results masking its presence until it causes a life-threatening bloodstream infection in vulnerable patients. In the United States, cases have surged dramatically, with the CDC reporting 4,523 diagnoses in 2023, a more than 50% increase from the previous year and nearly a tenfold rise since 2019. An additional 9,270 carriers were identified through screening tests that same year.

Doctors are particularly concerned about the fungus's resistance, which is nearly complete against one of the three major antifungal drug classes and is developing against the other two. According to Dr. Tom Chiller, former head of the fungal diseases branch at the CDC, infections caused by resistant strains are fatal for 29% to 62% of patients. The CDC has classified C. auris as one of its "urgent threats" among drug-resistant bacteria and fungi, which are estimated to cause approximately 9.7 million infections and 50,800 deaths annually in the U.S.

Professor Ronen Ben-Ami, Director of the Infectious Diseases Unit at Ichilov Hospital, has been familiar with the fungus for over a decade. He noted that C. auris behaves differently from typical Candida species, which usually cause infections in immunocompromised patients and do not typically lead to hospital outbreaks. However, around 2014, a new phenomenon emerged, with four C. auris bloodstream infections identified at Ichilov between May and October of that year, and another case at Wolfson Hospital in April 2015. Ben-Ami and colleagues described these cases in a 2017 paper, highlighting the fungus's unusual behavior, its simultaneous emergence on different continents, and its resistance to primary antifungal treatments.

Genetic analysis revealed that Israeli strains differed from those found in East Asia, South Africa, and Kuwait. The fungus can survive on patient skin, spread efficiently between individuals, and persist on surfaces and medical equipment, making it difficult to eradicate. Hospital cleaning protocols, even those using disinfectants, are less effective against C. auris.

The COVID-19 pandemic significantly accelerated the spread of C. auris, with hospital wards for COVID-19 patients acting as incubators for the fungus. In Israel, a sharp increase was observed in 2021, primarily around COVID-19 units, though the situation has since stabilized with sporadic outbreaks. Hospitals are implementing screening tests to identify carriers and prevent transmission through protective measures and isolation. However, the long duration of stays in geriatric facilities complicates containment efforts, as asymptomatic carriers can still spread the fungus when admitted to hospitals.

Carriage of C. auris does not always present symptoms, but active infections can lead to fever, inflammation, organ failure, septic shock, and death, especially in vulnerable patients. A significant challenge is determining when a patient is no longer a carrier, as the fungus can evade detection and reappear later, leading to prolonged isolation periods. While there are few treatment options due to antifungal resistance, new drugs are in clinical trials. Ben-Ami emphasizes that not all Candida infections are severe and that visitors can continue to see hospitalized relatives by adhering to simple precautions and following medical staff guidance.