Fungal infections develop drug resistance

Franklin Dobbs, a 76-year-old patient from Pappas, also had pre-existing lung problems before being diagnosed with aspergillosis last year. Dobbs said he had been hemorrhaging for about a year before being diagnosed. His case has so far not proven to be drug resistant.

An azole called Noxafil improved his symptoms, Dobbs said, although he still felt weak.

“I still have a problem with my leg strength,” he said.

Dobbs thinks he may have been exposed by planting tomatoes, corn and peas in the garden or building birdhouses outside.

A April study found that people can become infected with drug-resistant Aspergillus in their home gardens. The researchers collected lung samples from infected patients in the UK and Ireland, and compared some of them to drug-resistant strains in nearby environments.

Sometimes a single high-dose exposure, such as a cloud of spores released by digging in the ground, can be enough to trigger a fungal infection. But in many cases, people are gradually exposed to Aspergillus for months before they get sick.

“This is an extremely concerning superbug-like situation,” Armstrong-James said. “We all inhale this all the time. So potentially we could all be inhaling resistant Aspergillus daily. »

Unlike Aspergillus, Candida auris is mainly detected in hospitals, in people who are on breathing or feeding tubes or who are receiving a central line (an IV catheter that delivers fluids, blood, or medications).

“When you do any of these medical procedures on patients, you risk it getting into your bloodstream or creating an abscess, and that’s where it’s very dangerous,” said Luis Ostrosky, chief medical officer. infectious diseases at UTHealth Houston and Memorial. Herman Hospital.

More … than 90% of Candida auris strains are resistant to fluconazole, a common azole, and up to 73% are resistant to another called voriconazole. Some strains also have resistance to the drug that Fairweather recently stopped taking.

“You can end up with a patient with a Candida auris infection when you don’t have an antifungal to use for that patient. They’re resistant to everything,” Ostrosky said. “Basically, these patients go to hospice and die, and there’s nothing you can do about it.”

Why Mold Becomes Drug Resistant

The researchers identified two main drivers of resistance to antifungals: human drugs and chemicals used in agriculture.

Farmers often have rely on fungicides, but over time some strains of mold become resistant. And because fungicides are chemically similar to antifungal drugs, some strains of mold also develop drug resistance.

The 65-year-old man who died of invasive aspergillosis, for example, was infected with a strain linked to the use of agricultural fungicides, according to the CDC.

“Bulbs and onions that have been soaked in these antifungals so they don’t spoil are almost like time bombs. When planted, the fungicides on their surface escape into the environment. “said Armstrong-James, who co-authored the April study on Aspergillus.

“This could be a key breeding ground for resistance,” he added.

An x-ray image showing pulmonary aspergillosis. BSIP/UIG via Getty Images

Drug use contributes to resistance when antifungal drugs are prescribed too often, or if doctors do not prescribe a high enough dose or a long enough course. This can then exert selective pressure on the fungi.

“The more antifungals or antibacterials you use, the more resistance you see,” Pappas said.

Armstrong-James said hospitals see resistance to Candida auris more frequently than to Aspergillus.

“Anytime someone takes fluconazole, you can develop Candida resistance,” he said.

Climate change and Covid can each play a role

Climate change can catalyze the spread of Aspergillus and Candida auris.

Indeed, rising temperatures can lead to more fungicide resistance. Some research suggests that climate change was a key factor in the first appearance of Candida auris in humans in 2009.

“In a very short time, you have four or five different Candida auris families emerging more or less co-emerging simultaneously. How does that happen? It really screams if there’s something going on in the environment “Dads said. “There is decent evidence that climate change is at least one of the triggers.”

Some experts worry that as the effects of climate change intensify, even some healthy people could contract fungal infections.

“While there is no evidence at this time that a perfectly healthy person can contract a serious Aspergillus infection, there is nothing to say that with changing environments this may not change in the future. “, said Armstrong-James.

On top of all this, the Covid pandemic has created new opportunities for the spread of Candida auris. A July CDC report found that these infections increased by 60% in healthcare settings from 2019 to 2020.

“Invasive Candida infections skyrocketed with Covid, probably because all of those patients were sick,” Pappas said. “They were given broad-spectrum antibiotics. They had lines and ventilators and everything you need to generate invasive Candida.”

The CDC report found that staffing shortages and long patient stays, among other factors, made it difficult for some hospitals to prevent drug-resistant infections.

“We had all these traveling nurses who came from different parts of the country who weren’t necessarily aware of the protocols that the hospital normally has to prevent blood infections,” Ostrosky said.

“If the IV therapy stops working, I have no options,” Fairweather said.Andrew Testa for NBC News

New treatment options could take years

Doctors say they are in a race against time as current treatments could stop working before new ones become available.

“If we don’t deal with resistance now and strengthen the antifungal pipeline, we could very easily find ourselves in five to ten years where you’re having end-of-life discussions with a patient who has an invasive infection. to Candida,” Ostrosky said. “It’s just unthinkable right now that your loved one could go to the hospital and have an appendectomy, and have a complication, and end up with an incurable bug.

Several drugs have entered late-stage studies that could produce results in a year or two, experts said.

But Fairweather isn’t sure she’ll get the chance to try them.

“How much damage will be done to my lungs before these things take effect? ” she says.

Additionally, fungi could develop resistance to new drugs over time.

“Once they’re there they get overused and pretty quickly they’re not useful anymore,” Pappas said.

About Terry Gongora

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