Health officials are warning nursing facilities to be on the lookout for a rapidly spreading, drug-resistant disease.

New York, Illinois and New Jersey have been hit hardest by Candida auris, an emerging fungus that presents a “global threat,” according to the Centers for Disease Control and Prevention. C. auris is often resistant to drug treatment and can be particularly dangerous for sick older patients who have had invasive medical procedures, the Chicago Tribune reported Tuesday.

Illinois has experienced 154 cases so far, with the vast majority occurring in SNFs caring for patients on ventilators.

“It’s a combination of factors that makes you more prone to get a bug like this,” Max Brito, M.D., associate professor of infectious disease at the University of Illinois at Chicago, told the Tribune. “It’s a concern for people with a chronic disease or a weakened immune system.”

The fungus is often found on individuals’ skin and can spread in SNFs through contact with contaminated people or surfaces, according to Illinois health officials. One-third of patients die from C. auris when it reaches their blood, heart or brain. Those recovering from hard-to-heal wounds are also more susceptible to the infection.

Caregivers are urged to clean their hands with sanitizers or soap and water both before and after touching patients and medical devices, according to the CDC. And if a resident is colonized or infected with C. auris, he or she should be housed in a single room, if possible, and placed on contact precautions.

Providers in New York and New Jersey are figuring out how to respond on the fly, too, with 309 and 104 reported cases in those states, respectively.

“This is a fairly new occurrence and we are still learning how to deal with it,” Ted Louie, M.D., an infectious disease specialist at Robert Wood Johnson University Hospital, in New Brunswick, told NJ Spotlight.  “We have to figure out which disinfectant procedures may be best to try to eradicate the infection, so at this point, I don’t think we have good enough information to advise.”