First Cases of Potentially Fatal Fungus Reported in the United States

*Updated on 12/05/2016 at 11:25 AM EST

Following up on a clinical alert that was issued in June 2016, the Centers for Disease Control and Prevention (CDC) published an article in a recent Morbidity and Mortality Weekly Report that provides unsettling information on a deadly, emerging multidrug-resistant yeast known to cause invasive and life-threatening infections: Candida auris. According to the CDC, there have been seven cases reported in the United States thus far and six additional cases are under investigation.

C. auris was reportedly found in external ear discharge of a patient from Japan back in 2009. In response to this information, the CDC sought to determine if the fungus, which is associated with high mortality, was also present in the United States. Through a clinical alert issued in June, the CDC not only made healthcare officials aware of the fungus, but also issued a call to action: any Candida haemulonii or Candida spp. isolates must be reported and sent to public health laboratories as well as the CDC to be carefully analyzed and identified.

In the newly released report, the CDC confirmed the seven US cases of C. auris, all thought to have been identified between May 2013 and August 2016 (one each in 2013 and 2015, and the remaining five this year). These cases were identified in four states: Maryland (one), New Jersey (one), Illinois (two from the same hospital), and New York (three, from three different hospitals).

To understand how and where this fungus had been transmitted, the researchers investigated if any of the patients had recently traveled outside of the country. They found that only one patient, from New York, had recently been transferred from a hospital in the Middle East. Looking for any overlap among the patients, the researchers also reviewed the case history for the patients who had been at the same hospital in Illinois. They found that the two patients had been admitted to the same hospital, three different times, but had been in different wings or on different floors. Additionally, they found that even though the dates never overlapped, the same two patients were both admitted to the long-term acute care hospital within days of one another.

The researchers also took a closer look at the patients from Maryland and New Jersey, and found that both had been hospitalized at the same New Jersey hospital at the same time, but in different wards. Further, the researchers found that all of the samples (from the mattress, chair, windowsill, among others) taken from the hospital room of one of the patients revealed the presence of C. auris; these findings suggest the possibility of transmission within healthcare settings. It was noted that all of the identified patients (1) had serious medical conditions that ranged from bone marrow transplantation to brain tumors and (2) were treated with echinocandins. One patient was also given liposomal amphotericin B, an antifungal medication. Despite the fact that all of the patients with bloodstream infections eventually showed “documented clearance of C. auris from the bloodstream,” as of August 31, four of the patients died.

There are several reasons why C. auris poses a larger global health threat. Many of the isolates have developed resistance to a number of drugs, making the infections that are caused by this fungus exceedingly difficult to treat. Additionally, "specialized methods, such as matrix-assisted laser desorption/ionization time-of-flight or molecular identification based on sequencing the D1-D2 region of the 28s ribosomal DNA," are needed in order to correctly identify the fungus. Another issue is misdiagnosis: according to the CDC, "When using common biochemical methods such as analytic profile index strips of the VITEK 2, the fungus is sometimes mistakenly identified as other yeasts."

Because of these reasons, the CDC is working to decrease the risk of transmission as well as promote effective infection control in healthcare facilities. The CDC is urging these facilities to use standard and contact precautions when it comes to C. auris patients. In addition, they specifically mention that providers should keep in mind two factors when it comes to nursing homes in particular: the level of patient care and the presence of transmission risk factors. If patients are being transferred to another healthcare facility, the new facility must be informed of the presence of the fungus so that proper preventive precautions can be taken.

Disinfection is incredibly important to avoid contamination and reduce the risk of transmission, particularly within the healthcare setting. The CDC states, “Facilities should ensure thorough daily and terminal cleaning of rooms of patients with C. auris infections, including use of an EPA-registered disinfectant with a fungal claim.” Healthcare facilities also should continue to report any possible cases and send any samples of C. haemulonii and Candida spp. that they find to the CDC or public health laboratories for testing.

Feature Picture Source: CDC Press Release [http://www.cdc.gov/media/releases/2016/p1104-candida-auris.html]