(NEXSTAR) – A potentially deadly fungus that’s resistant to treatment has been confirmed in at least 28 states, the Centers for Disease Control and Prevention warned, but identifying the dangerous pathogen is actually quite difficult.

Candida auris, or C. auris for short, isn’t possible to identify with commonly available lab tests, making the already dangerous fungus even harder to treat early and properly.

To make matters even more complicated, symptoms of a Candida auris infection aren’t distinct from other (much more common) infections.

Symptoms can include high fever and chills — common signs your body is fighting an infection of some sort. If they don’t go away with antibiotics, that could be one indication it’s Candida auris, according to Mount Sinai Hospital.

Because the symptoms aren’t distinct, a Candida auris infection is often diagnosed “based on epidemiologic scenarios” and context clues, explained Melissa Nolan, an assistant professor of epidemiology and biostatistics at the University of South Carolina.

“For example, a hospitalized immunocompromised patient with fever who doesn’t recover after given antibiotics or anti-fungals would be considered at-risk for C. auris,” Nolan said.

The spread of the fungus is so concerning for a trio of reasons: it has developed a resistance to treatment; it spreads in environments where people are sick or otherwise weakened, like hospitals or nursing homes; and it’s hard to identify.

“This fungal species requires a very specific diagnostic test that is not commonly available, therefore we are seeing patients whose infection was initial misdiagnosed due to a lack of the correct test,” Nolan said. She suggested doctors who suspect they might be looking at a case of Candida auris order a specific culture to test for it, allowing them to identify which types of drugs they have as options to treat the infection.

While the fungus is resistant to many medications, there are a “very limited number” that still work, Nolan said. But a proper diagnosis is needed first.

The CDC estimates that “based on information from a limited number of patients, 30–60% of people with C. auris infections have died. However, many of these people had other serious illnesses that also increased their risk of death.”

The fungus was first detected in the United States in 2016, but it started spreading especially fast between 2021 and 2022. Since then, Candida auris has been found more than 8,000 times in at least 28 states, according to CDC tracking.