A drug-resistant super fungus capable of making millions sick has been discovered in one of the most remote corners of the earth – raising fears of a widespread disease outbreak.
Canadian researchers identified a common type of fungus thousands of meters above sea level in a mountainous region in southwest China that had evolved to become resistant to common medicines used to treat infections.
Fungi can become resistant to treatment after extended bouts of exposure to drugs or fungicides used for agricultural practices, though the samples collected in China were far removed from farmlands and human activity.
As treatment-resistant fungi become more common, experts are worried that they could be the source of the next global pandemic.
The fact that the fungal samples collected in more remote areas of the valley showed the same level of antifungal resistance as those samples taken from areas where fungicides are more commonly used indicates that a wider spread of harder-to-treat fungi is likely to occur
Lead researcher Jianping Xu, from McMaster University in Ontario, Canada, discovered the drug-resistant strain of Aspergillus fumigatus in the Three Parallel Rivers region in southern China, nestled within the eastern Himalayas.
The type of fungus is a common mold that releases airborne spores called conidia so readily that humans unknowingly inhale hundreds of them every day without getting sick.
But the discovery of a thriving drug-resistant variation could spell danger for humans, according to Dr Xu, whose work also pertains to pandemic preparedness.
Fungal infections caused by Candida auris are becoming more prevalent in the US and Europe.
In fact, infections rose more than eightfold in the US from 2017 to 2021, from 171 annual cases to 1,420. The mortality rate for C. auris infection ranges from 30 to 60 percent in people who have weakened immune systems.
Experts fear that an aggressive fungus could be the source of another global pandemic.
Relatively few species of fungi are believed to cause infections in humans, but with an ever-warming global climate making the environment more hospitable to pathogens and fungicide overuse in agriculture, the threat of fungal disease in humans looms a bit larger.
The team from McMaster University ventured to the remote Three Parallel Rivers region in Yunnan, a unique geographical area nestled amid glacial peaks and mountains extending more than 4.2 million acres.
They sampled 331 strains of A. fumigatus across nearly 2,000 soil samples and found that nearly seven percent were resistant to common antifungal infection treatments itraconazole and voriconazole.
Dr Xu said: ‘Seven percent may seem like only a small number, but these drug-resistant strains are capable of propagating very quickly and taking over local and regional populations of this species.
‘There is a need for increased surveillance of drug resistance in the environment across diverse geographic regions.’
The findings were published in the journal mSphere.
Some 4.8 million people globally have a type of lung disease that comes from an allergy to Aspergillus.
Most types of the aspergillus species are harmless, but inhaling A. fumigatus spores can lead to severe aspergillosis infection in immunocompromised individuals or people with underlying lung disease. An estimated three to four million people worldwide are sickened by aspergillosis every year.
Dr Xu said: ‘This fungus is highly ubiquitous — it’s around us all the time. It is estimated that we all inhale hundreds of spores of this species every day.
‘It can be very dangerous — it can lead to lung removal or even death — and now, increasingly, many of these infections will be impacted by drug resistance.’
The fact that the fungal samples collected in more remote areas of the valley showed the same level of antifungal resistance as those samples taken from areas where fungicides are more commonly used indicates that a wider spread of harder-to-treat fungi is likely to occur.
The authors of the study pointed out that drug-resistant fungi can spread from agricultural fields to non-agricultural areas readily through human influence such as travel and trade, as well as through weather and runoff.
The outlook for Aspergillus is murkier, as the Centers for Disease Control and Prevention does not track it in the same way. But serious aspergillus infections are estimated to cause roughly 14,000 hospitalizations annually.
Unlike Candida auris, which is primarily detected in hospitals, people can contract treatment-resistant aspergillus from their home flowerbeds.
An April 2022 study published in the journal Nature Microbiology tested this by collecting lung samples from infected people in the UK and Ireland and matched some of them to drug-resistant strains in nearby environments.
***
Read more at DailyMail.co.uk