Between April 1, 2020 and March 31, 2021, the Centers for Disease Control and Prevention (CDC) received reports of more than 800 cases of infection by the C. auris fungus, a growing problem that the agency terms "a serious global health threat," wrote Rodney E. Rohde, Professor of Clinical Laboratory Science, Texas State University, in an article posted by The Conversation.
Infections by C. auris, sometimes called fungemia, have been reported in 30 or more countries, including the United States. They are often found in the blood, urine, sputum, ear discharge, cerebrospinal fluid and soft tissue, and occur in people of all ages. According to the CDC, the mortality rate in the U.S. has been reported to be between 30% to 60% in many patients who had other serious illnesses.
In a 2018 overview of research to date about the global spread of the fungus, researchers estimated mortality rates of 30% to 70% in C. auris outbreaks among critically ill patients in intensive care.
Research data from the CDC shows that risk factors include recent surgery, diabetes and broad-spectrum antibiotic and antifungal use. People who are immuno-compromised are at greater risk than those with healthy immune systems.
C. auris can be difficult to identify, according to the CDC with conventional microbiological culture techniques, which leads to frequent mis-identification and under recognition. This yeast is also known for its tenacity to easily colonize the human body and environment, including medical devices. People in nursing homes and patients who have lines and tubes – like breathing tubes, feeding tubes and central venous catheters – seem to be at highest risk.
The CDC have set C. auris infections at an “urgent” threat level because 90% are resistant to at least one antifungal, 30% to two antifungals, and some are resistant to all three available classes of antifungals. This multidrug resistance has led to outbreaks in healthcare settings, especially hospitals and nursing homes, that are extremely difficult to control. For hospitalized COVID-19 patients, antimicrobial-resistant infections may be a particularly devastating risk of hospitalization. The mechanical ventilators often used to treat serious COVID-19 are breeding grounds and highways for entry of environmental microbes like C. auris.
Further, according to a September 2020 paper authored by researchers Anuradha Chowdhary and Amit Sharma, hospitals in India treating COVID-19 have detected C. auris on surfaces including “bed rails, IV poles, beds, air conditioner ducts, windows and hospital floors.” The researchers termed the fungus a “lurking scourge” amid the COVID-19 pandemic.
The same researchers reported in a November 2020 publication that of 596 COVID-19-confirmed patients in a New Delhi ICU from April 2020 to July 2020, 420 patients required mechanical ventilation. Fifteen of these patients were infected with candidemia fungal disease and eight of those infected (53%) died. Ten of the 15 patients were infected with C. auris; six of them died (60%).
With the options for effective antifungals narrowing, the CDC is recommending a focus on stopping C. auris infections before they start. These steps include better hand hygiene and improving infection prevention and control in medical care settings, judicious and thoughtful use of antimicrobial medications, and stronger regulation limiting the over-the-counter availability of antibiotics.