Dear Doctor: First, there was a "superbug bacteria"; now there's a "superbug fungus"? What is this new fungus that I've been reading about? More to the point, how worried should I be?
Dear Reader: Unfortunately, yes, a type of yeast known as Candida auris has been identified as a source of serious illness in a growing number of hospital patients, both in the United States and abroad. Not only is it resistant to existing treatments, it has also eluded efforts by health care personnel to halt its spread.
Yeasts are single-celled microorganisms that are members of the fungus kingdom, which also includes molds and mushrooms. They're everywhere -- in the soil, on vegetation, in waterways and on living creatures, including humans.
Candida yeasts are typically found in the intestinal tract, as well as on mucous membranes and other areas of warm, moist skin. While more than 150 species of Candida have been identified, only about 15 of them are known to cause infections.
For the most part, these tiny organisms live peaceably with their hosts, held in check by the other microbiota that call us humans home. However, factors like stress, taking antibiotics or antifungals, and a weak immune system, to name just a few, can lead to an overgrowth of Candida yeasts. This can result in symptoms such as itching, rash, fatigue or gastrointestinal distress, which vary depending on the area that is infected.
The good news is that most Candida infections are easy to recognize and respond well to treatment. If you've ever had athlete's foot, a vaginal yeast infection, jock itch, diaper rash or oral thrush, then you've had a Candida fungus skin infection. Nail fungus, also caused by Candida, is more difficult to eradicate due to its positioning beneath the nail bed.
The very bad news is that unlike its relatives, Candida auris is emerging as a serious health threat. First identified in 2009 in Japan, the organism has spread globally. As of August 2017, it was responsible for 112 infections in the U.S., more than half of those in 15 different New York City hospitals.
Candida auris is resistant to all three major classes of antifungal drugs. It persists in hospitals and is spread between patients. It's particularly dangerous to people with weak immune systems, such as newborns and the elderly. It can enter a patient's blood stream via wounds, as well as lines or tubes entering the body. Once in the body, it can cause serious invasive infections. Rapid response is crucial, but it is made difficult because Candida auris is difficult to identify.
At first, travel was suspected in the global spread of Candida auris. However, genome sequencing, which is basically a DNA fingerprint, revealed enough differences between regional strains to suggest the yeast has sprung up independently. Needless to say, all aspects of Candida auris are now under intense study.
For all these dire details, you don't have to be alarmed. In most cases, infections occurred in patients who were hospitalized, most of them for several weeks. In the meantime, identifying new treatments and stopping the spread of Candida auris has become an international priority.