A fungus that can infect humans has been discovered in China.
Two men, in their 60s and 80s, have already died from infections with the pathogen, R. fluvialis. It is unclear whether the fungus contributed to their deaths.
Researchers at Nanjing Medical Center who made the discovery fear that others may also be infected with the disease, which is caused by a type of yeast.
An experiment in mice showed that R. fluvialis mutates rapidly, suggesting that the same could happen in humans if the bacteria were to spread widely.
Scientists have announced that they have discovered a new fungus that can infect humans, called Rhodosporidiobolus fluvialis (stock image)
The fungus was discovered during examination of samples from tens of thousands of patients treated in hospitals across China between 2009 and 2019.
The two men did not know each other — they lived nearly 500 miles apart. There was a three-year difference between when they were admitted to the hospital
They also had weakened immune systems: one man was taking immunosuppressive drugs, the other had diabetes.
However, the cases have raised concerns, especially after laboratory tests showed the new fungus was resistant to three commonly used first-line antifungal treatments (fluconazole, caspofungin and amphotericin B).
A separate experiment using immunocompromised mice showed that R. fluvialis mutates rapidly, forming ‘hypervirulent mutants’.
And in a petri dish, it mutated 21 times faster at human body temperature than at room temperature, increasing the risk of more dangerous strains emerging.
At this stage, scientists say it is unclear how the patients became infected and whether the fungus contributed to their deaths.
But in many cases, fungal infections, such as C. auris, are acquired in hospitals after patients are admitted for separate conditions.
C. auris can spread to the blood and cause sepsis, where the immune system overreacts to an infection. It is fatal in about 30 percent of cases.
Dr David Denning, an infectious disease expert at the University of Manchester in the UK, said Living science — which the study concluded was a “remarkable finding” that “only bodes ill for the future.”
According to Dr Matthew Fisher, a fungal disease epidemiologist at Imperial College London, we should not yet view the fungus as a major, emerging threat.
“My first impression is that there are environments in China where these yeasts exist that have not been studied before,” he said.
“These two patients were unlucky enough to be exposed.”
The 61-year-old patient was admitted to a hospital in Nanjing in 2013 with severe pancreatitis (an inflammation of the pancreas) and kidney damage.
He died of multi-organ failure after being treated with antifungal drugs.
The 85-year-old patient was admitted to a hospital in Tianjin, about 500 miles (800 kilometers) to the north, in 2016 with pneumonia.
He was also treated with antifungal drugs, but died of respiratory failure.
Over the past ten years, a total of 27,100 fungal strains have been found in hospital patients.
Of these strains, rare fungi accounted for only 1.7 percent of the strains, of which only one, R. fluvialis, was a new species that had not previously been recorded.
The scientists said their paper also highlighted the risk that global warming would cause new pathogens to emerge, as the fungus mutated more at higher temperatures.
The research was published in the journal Nature Microbiology.