Melissa Golden for the New York Times

For decades, human medicine has relied on antibiotics, antifungals, and other drugs to keep people healthy. Recently, some diseases have shown themselves with a new resiliency that defies the effects of these treatments. The latest of these, a fungus called Candida auris (C.auris), is particularly concerning. It spreads easily, targets people with compromised immune systems. is tough to slow or to kill, and can be fatal.

Fungus Proves Especially Deadly

The fungus was first identified in 2009 in Japan. One of the most concerning things about the bug is that once it is contracted, it can cause an invasive and lethal blood infection. In a recent Spanish outbreak,17 out of 140 affected patients died. Across the world, it proves fatal to approximately 60 percent of people who contract it. In the U.S., the Center for Disease Control and Prevention (CDC) estimates these number at 30 percent. Though those are much lower numbers, they’re still pretty elevated.

Fast-spreading Fungus Goes Everywhere

Caregivers have been astounded by the rate at which the C.auris germ can spread. Even with medical-grade sanitizing measures in place, the fungus has maintained a strong presence. In London, a patient contracted it and, within a week, the patient located just a bed over had it also. Within a month, two more people had it and the hospital tested the intensive care unit.

Staff at the hospital were shocked to find the fungus growing on the treatment unit’s floors, radiators, windowsills, equipment monitors, and keypads. This happens because as hospital staff members treat C.auris, the risks run high that they will spread it. Contaminated temperature probes, medical monitoring devices, and other standard hospital equipment can all carry the fungus once they come into contact with it.

This situation at the London hospital has repeated itself in other medical facilities around the world. Mt. Sinai Medical Center in New York had to go so far as to entirely rip out entire sections of ceiling tile in order to eradicate the disease in their unit after an elderly gentleman died from it.

Resistance To Treatment Makes The Fight Harder

Medical professionals and researchers are also concerned about this fungus’ ability to resist known treatments. It has shown time and time again that it doesn’t always respond to major antifungal treatments that doctors have in their arsenal of fighting tools. Though doctors may try to use both first and second line antifungals, if those don’t work then there aren’t necessarily going to be a lot of other options to try.

Multiple Types Of Serious, Resistant Microbes

C.auris isn’t alone in its ability to resist the antimicrobial tools of modern medicine. Other resistant infections include MRSA, C.diff, and the especially frightening flesh-eating bacterial disease necrotizing fasciitis.  Lists of resistant bugs can be found from a number of sources including the CDC and the World Health Organization.

Doctors, researchers, and other health professionals are taking these diseases seriously because they’re seeing fatal impacts for so many patients. In the U.S. alone, the C.D.C. estimates that two million people contract resistant infections each year, with 23,000 of these patients unable to survive the illness. Throughout the world, fatalities from resistant infections are believed to reach as high as 700,000 patients.

Overuse Of Antimicrobial Treatments

One theory about why the bugs are so resistant to treatment is that, over time, they’ve encountered and developed defenses to the medicines designed to kill them. Frequent medical use of antimicrobial drugs in patients is one very common way to facilitate this. Organisms may also gain exposure to antimicrobial drugs,  as they’re used in farming and meat production.

As people take their prescriptions or consume food they expose their bodies and any fungus or bacteria, to the agents. The doses are low enough that they don’t kill the bugs, but the bugs find ways to fight them and grow stronger

Too Many Antibiotics May Weaken The Human Biome

Another drawback to an overuse of antibiotics is that it weakens the human biome, the groupings of fungus, bacteria, and other germs that play a strong role in human health. Human beings and other animals are constantly covered in microbes which may have as much potential for good as they do for harm.

The medical community’s understanding of these microbe communities are continuing to evolve, but it is believed that there are sets of good bacteria and fungus which constantly work to keep down populations of bugs that keep people sick. Unfortunately, microbial agents, particularly stronger ones, don’t distinguish between the two. Everything can be killed, giving the bad bugs every chance to re-grow first and cause illness.

Handwashing, Less Use Of Antimicrobials Can Help

While superbugs are a big problem, there are plenty of things that can be done to help. One of the simplest, frequent handwashing, can be practiced by just about everyone. The CDC has asked people to lather their hands vigorously for at least 20 seconds (try whistling a tune to get a better sense of the timing here) and then to rinse and towel dry after. They ask people to be particularly conscious about doing this during food handling (especially with raw meats) sneezing, coughing, or using the restroom, or coming into contact with any bodily fluids.

Experts looking to lower the use of superbugs have also been encouraging a lower use of antimicrobial treatments in medical settings and agricultural processes. It is hopeful that all of these activities can address the spread of treatment-resistant bugs and, ultimately, keep humans healthier for longer.