Two types of fungi, Aspergillus and Candida auris, are becoming harder to treat with the drugs commonly used for such infections.
Jill Fairweather at her home in Holyport, England.Andrew Testa for NBC News

By Aria Bendix

After living with a severe fungal allergy for about 40 years, Jill Fairweather is running out of treatment options.

Now 65, Fairweather was diagnosed with aspergillosis, a disease caused by the common mold Aspergillus, in her 20s. The illness can result from an allergic reaction or an infection in the lungs. Over the years, Fairweather has tried medication after medication, switching once side effects get too dangerous or the fungus develops resistance.

Aspergillus and another fungus, Candida auris, are growing resistant to the treatments frequently used to fight them — in particular, a class of drugs called azoles.

"If we lose that drug class because of resistance, we’re in for big trouble," said Darius Armstrong-James, an infectious disease physician at Royal Brompton Hospital in the U.K.

Fairweather has a rattle in her chest that she said feels as if she’s trying to expel a piece of rubber. Sometimes she coughs up blood. 

After she developed resistance to an inhaled antifungal medication often considered a last resort, Fairweather started on an intravenous drug cocktail that recently required a two-week stay in the hospital on an IV drip. 

"If the intravenous treatment stops working, I’ve run out of options," she said.

Globally, around 4.8 million people have lung disease from allergy-based aspergillosis like Fairweather's, according to a 2013 estimate. The survival rate of chronic lung disease from aspergillosis was 62% at five years and 47% at 10 years, a 2017 study found.

Jill Fairweather’s daily dose of medications.Andrew Testa for NBC News

Doctors anticipate more cases like Fairweather's as fungal infections become more prevalent in Europe and the U.S.

Candida auris infections rose more than eightfold in the U.S. between 2017 and 2021, according to the Centers for Disease Control and Prevention — from 171 annual cases to 1,420. In the U.S., the mortality rate of an invasive Candida auris infection ranges from 30% to 60%.

That fungus usually affects people in health care settings. In May, Nevada's state health department recorded Candida auris outbreaks at 19 hospitals and nursing facilities

The CDC does not track aspergillosis in the same way, so it's hard to know how prevalent cases are. But hospitalizations related to invasive aspergillosis — severe infections in people with weakened immune systems — rose 3% annually from 2000 to 2013, according to one study. A CDC report published Wednesday showed that the U.S. recorded more than 14,000 hospitalizations for invasive aspergillosis each year. 

The report highlighted the case of a 65-year-old man who underwent a stem cell transplant. Afterward, doctors prescribed him azoles to ward off a fungal infection, but they detected Aspergillus in his lungs more than three weeks into his hospital stay. A second type of azole also failed to stop his infection, and he died less than a week later. 

The report determined that the patient had been infected with an Aspergillus species that’s resistant to azoles — one of the same strains Fairweather has.

Patients with invasive aspergillosis from this drug-resistant strain have a mortality rate of around 60%, according to the CDC.

How fungi invade the body

Most healthy people inhale Aspergillus frequently with no consequences. The spores lingers in damp homes, soil, seeds and decaying vegetation. 

"You live on Earth and breathe, you’re going to get Aspergillus in your lungs," said Dr. Peter Pappas, a professor of medicine at the University of Alabama at Birmingham.

But in people with weakened immune systems or chronic lung conditions, the fungus is a threat. 

Fairweather, who lives in Berkshire, England, had severe asthma as a child, which likely made her more susceptible to aspergillosis. Still, she took corticosteroids and lived fairly normally until her 40s, when she started to get ill frequently. 

If she caught a cold, Fairweather said, “I would end up being off work for two weeks and have a chest infection or end up with pneumonia.”