Doctors in Canada are being warned about the emergence of an extremely contagious pathogen described as a “fungal superbug” that is resistant to most medications and can be deadly for patients who are already sick.

First identified in Japan 10 years ago, the fungus Candida auris or C. auris is now present in 17 countries, including Canada. It’s being called a public health threat because it’s easily spread through skin contact, it’s difficult to identify, it’s resistant to most antifungal drugs, it’s hard to kill, and it’s particularly lethal for patients who are already ill.

“Five years ago, nobody cared about it because we just thought it was kind of ordinary and we had a bunch of drugs and they were OK, and to be faced with a serious resistance problem in Canada is, I think, completely unexpected,” Dr. Allison McGeer, the medical director of infection control at Sinai Health System, told CTV News.

Now, Canadian doctors are being warned about the appearance of C. auris after 19 cases were identified in the country so far, along with one reported hospital outbreak. South of the border, there have been 640 cases in recent years with the U.S. Centers for Disease Control (CDC) labelling it a “serious global threat.”

According to the CDC, the pathogen is particularly worrisome because it’s “multidrug-resistant,” it’s difficult to identify with standard laboratory methods, and it’s responsible for outbreaks in healthcare settings.

Although C. auris doesn’t affect healthy individuals, they can carry it on their skin and transfer it to sick patients when they visit a hospital, for instance. The CDC said the fungus can cause bloodstream infections, wound infections, and ear infections – sometimes with fatal outcomes.

In fact, the health agency estimates that 30 to 60 per cent of patients with C. auris infections have died. They acknowledged, however, that many of these people had other serious illnesses that may have increased their risk of death.

In terms of treatment, Julianne Kus, a clinical microbiologist for Public Health Ontario, said it’s difficult because they have seen C. auris be resistant to the three major classes of antifungal drugs in testing.

“This is new and unusual,” she told CTV News. “It also appears to be more drug resistant than any of the yeast species that we are familiar with in the clinical setting. It means we don’t have a lot to work with in terms of treatment.”

As healthcare officials strive to increase awareness about the pathogen, particularly in hospitals, efforts to protect against it are proving to be especially challenging. That is because the fungus sticks to surfaces and isn’t easily removed using traditional cleaning methods.

In one case, workers at an American hospital experiencing an outbreak of C. auris were forced to rip out ceiling and floor tiles to completely eradicate the contagious bug.

McGeer said the pathogen’s spread is raising questions about what kind of response Canadian healthcare centres should take to prevent an outbreak. In January, Public Health Ontario released its own guidelines on C. auris, which included information on how to prevent the pathogen’s spread, how to identify it, and how to treat it.

“What do we have to do to control it? What extra cleaning? Additional precautions? There is a whole list of questions about the right response,” she said.

They are questions the World Health Organization says require urgent attention as the pathogen spreads and drug-resistance becomes an ever-pressing global health problem.