New fungal infection discovered in China capable of infecting humans

Scientists in China have discovered a previously unknown fungal infection that is capable of infecting humans, can survive inside the human body and become more resistant to drugs when exposed to higher temperatures.

The fungus, called Rhodosporidiobolus fluvialis, or R.fluvialis for short, was found in clinical samples from two patients not connected to the hospital.

In experiments, scientists found that the fungus was resistant to many common antifungal drugs at higher temperatures, close to human body temperature.

This temperature led to the emergence of "hypervirulent mutations" capable of causing more severe disease in laboratory mice.

The findings "support the idea that global warming can promote the evolution of novel fungal pathogens," the scientists wrote in a report published June 19 in the journal Nature Microbiology.

The team made the discovery after examining fungal samples from patients in 96 hospitals across China between 2009 and 2019.

In total, 27,100 strains of fungi were collected and analyzed, and of these, only R.fluvialis has ever been seen in humans before.

R.fluvialis was detected in the blood of two unrelated patients. In addition to being infected with the fungus, they had serious health conditions.

One patient was a 61-year-old man who died in an intensive care unit (ICU) in Nanjing in 2013, and the other was an 85-year-old man who died in 2016 after being treated in an ICU in Tianjin. The report does not indicate whether the fungal infection directly contributed to the deaths of these patients or if they had been infected at the time.

As part of their treatment, patients were given common antifungal medications, including fluconazole and caspofungin.

Laboratory studies conducted by the team later found that R.fluvialis bacteria were resistant to both drugs.

The finding “bodes ill for the future,” David Denning, a professor of infectious diseases at the University of Manchester in the United Kingdom, who was not involved in the research, told Science magazine.

But for R. fluvialis, specifically, some scientists argue against the worrying conclusions. Matthew Fisher, a professor of fungal disease epidemiology at Imperial College London who was not involved in the research, tells Science that the fungus should not yet be viewed as a major, emerging threat.

“My first feeling here is that there are untested environments in China where these yeasts live, and that these two patients were unlucky enough to be exposed to them,” he added. “In short, there is no evidence that R.fluvialis is widespread in the population, despite its worrisome features.”