Fungal infections could become resistant to medication and cause an epidemic in humans, crops and animals, experts warn.
Like the increasing number of bacteria that are becoming antibiotic resistant, fungi could also one day be incurable.
Researchers led by Imperial College London and the University of Exeter caution that overusing anti-fungal treatments in farming and medicine could be making them less effective.
Resistant fungal infections could cause widespread crop failures and be deadly for people with conditions such as a weakened immune system from having cancer.
One researcher says the threat is ‘under-appreciated’ and ‘immediate’.
Fungi destroy a fifth of global crop yields each year, and cause diseases which kill more people than breast cancer or malaria, scientists say
Regular use of the type of antifungal used to treat thrush, athlete’s foot, ringworm and fungal nail infections is partly to blame, the scientists say.
The drugs – which were discovered in the 1950s and are called azoles – also account for about a quarter of fungicides used in agriculture.
It is thought they kill off weaker strains of fungal infection but stronger strains survive the treatment and continue to spread.
The scientists’ research says fungi are responsible for a range of infections in humans, animals and plants.
These include blights which can wipe out food crops, yeast infections which can lead to blood poisoning in humans and livestock.
Fungi destroy a fifth of global crop yields each year, and cause diseases which are estimated to kill more people than breast cancer and malaria.
Scale of the problem is under-appreciated
Study author Professor Matthew Fisher, from Imperial’s School of Public Health said: ‘The threat of antimicrobial resistance is well established in bacteria, but has largely been neglected in fungi.
‘The scale of the problem has been, until now, under-recognised and under-appreciated.
‘But the threat to human health and the food chain are serious and immediate.
‘Alongside drug discovery and new technology, we urgently need better stewardship of existing antifungals to ensure they are used correctly and that they remain effective.
‘Fungi are a growing threat to human and crop health as new species and variants spread around the world, so it is essential that we have means to combat them.
‘However, the very limited number of antifungal drugs means that the emergence of resistance is leading to many common fungal infections becoming incurable.’
Fungal disease a big killer and quick to spread
The review paper, published in a special edition of the journal Science, says the number of human deaths from fungal diseases is comparable to those caused by tuberculosis and HIV.
Fungi also cause chytrid – the ‘amphibian plague’ wiping out amphibian species around the world.
Like bacteria, fungi are thought to be able to ‘swap’ genes with one another, helping resistance to spread.
And their rapid rate of reproduction means resistant strains can quickly increase their number.
Global trade and migration of people, animals and food is also helping resistance to spread.
Resistance in crops has been driven by intensive farming practices along with cultivation of relatively few crop species and overuse of existing chemicals to keep them free of disease.
Professor Fisher explains: ‘The emergence of resistance is leading to a deterioration in our ability to defend our crops against fungal pathogens.
‘The annual losses for food production has serious implications for food-security on a global scale.’
Newer drugs are needed and should be used selectively
The danger for human health is when this resistance occurs in mould species such as Aspergillus fumigatus.
These thrive on decaying plants but are also able to infect people with compromised immune systems, such as cancer patients or those who have received organ transplants.
Researchers say antifungals should be used more selectively, and there should be a focus on developing new drugs.
Treatments aimed at silencing the genes of fungi and stopping them from spreading could also help to tip the balance in the fight against fungal pathogens.
Professor Sarah Gurr, from the University of Exeter said: ‘Emerging resistance to antifungal drugs has largely gone under the radar.
‘But without intervention, fungal conditions affecting humans, animals and plants will become increasingly difficult to counteract.’