(NEW YORK) — Public health departments across the United States have expressed concern about the spread of a potentially deadly fungus after the Centers for Disease Control and Prevention reported cases have spiked.

Candida auris, or C. aurisis, is increasing at an “alarming” rate with cases doubling in 2021, the CDC said.

Now, with infections reported around the country, health officials are working to prevent the drug-resistant yeast from spreading further.

Two cases were recently reported to the Colorado Department of Public Health and Environment. The agency told local ABC affiliate Denver 7 that the patients had been receiving care in facilities out of state and were transferred to Colorado for additional care.

On its website, CPDPHE said it was concerned about C. auris because it is often multi-drug resistant, can be difficult to identify and can cause outbreaks in health care settings.

Additionally, the Indiana State Department of Health said it is monitoring 87 cases of C. auris, according to local affiliate WRTV.

The fungus “presents a serious global health threat,” the department said on its website. “Outbreaks of this organism have occurred in healthcare settings, so early identification and communication about cases are essential to awareness and prevention.”

What’s more, Austin Public Health recently told KXAN that the spread was “very concerning” and that it is a “top threat” to the agency.

While most healthy people are not at risk, vulnerable populations — including those with weakened immune systems — are prone to drug-resistant infections.

In addition, nursing home patients or hospital patients who have or have had lines and tubes in their body — such as a catheter or a breathing tube — are also at high risk.

Doctors previously told ABC News they are concerned because C. auris can spread either from person to person or by coming into contact with contaminated surfaces.

Although several strains of C. auris are multi-drug resistant, there is a class of antifungal drugs called echinocandins that can be used and are given intravenously.

According to the National Institutes of Health, echinocandins prevent a key enzyme needed to maintain the cell wall of the fungus.

In some cases, when the infection is resistant to all three main classes of drugs, multiple high doses may be required, the CDC said.

According to the CDC, studies on mortality related to C. auris are limited but anywhere between 30% and 60% of people with C. auris infections have died.

The federal health agency, however, noted many of these patients also had other serious illnesses that increased their risk of death.

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