There is a danger of “global collapse” when it comes to controlling and fighting fungal infections if resistance to treatments continues to grow, scientists warned last night.
An international team, led by researchers from Imperial College London and the University of Exeter, in England, warn the increase in resistance to antifungal treatments mirrors the well-established threat of bacteria that have become resistant to antibiotics.
They say there must be improvements in how existing drugs are used, as well as an increased focus on finding new treatments.
Writing in a special edition of Science, the teams highlight the unprecedented rise in emerging strains of fungi that are resistant to common antifungal drugs (AFDs).
They warn that many drugs used to treat fungal infections in plants and animals are in danger of becoming ineffective and they fear the same could happen to those treatments used for human infections.
They also believe overuse of existing antifungal chemicals is helping resistance to spread and is increasingly rendering treatments ineffective.
Professor Matthew Fisher, from the School of Public Health at Imperial and first author of the study, 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 to tackle fungal pathogens, 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 pathogens are responsible for a broad range of infections in humans, animals and plants. They include blights that can wipe out food crops, yeast infections that lead to blood poisoning in humans and livestock, as well as chytrid.
Scientists believe that the direct threat to human health from crop-destroying fungi is increasingly significant, with about 20% of crops destroyed across the world each year as a result of fungi.
It is estimated that the number of human deaths from fungal diseases is comparable to numbers of those caused by tuberculosis and HIV.
In this latest review paper, the authors cite global trade networks and the increased movement of people, animals and food around the world, as key drivers in helping resistant strains of fungi to spread rapidly.
The fungi are believed to ‘swap’ genes with one another, helping resistance to spread. Their rapid rate of reproduction means resistant strains can quickly increase their number.
Professor Fisher said: “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.”
He adds that fungicides used in agriculture are also leading to the emergence of antifungal resistance in human fungal pathogens.
Professor Sarah Gurr, from the University of Exeter, added: “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.”
Fisher M et al. Worldwide emergence of resistance to antifungal drugs challenges human health and food security. Science 17 May 2018.
http://science.sciencemag.org/cgi/doi/10.1126/science.aap7999
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