An international team warns that improvements are needed in how existing drugs are used. There should also be an increased focus on the discovery of new treatments, in order to avoid a “global collapse” in our ability to control and fight fungal infections.
The rise in resistance to antifungal treatments mirrors the well-established threat of bacteria which have become resistant to antibiotics, according to the researchers led by Imperial College London and the University of Exeter.
Professor Matthew Fisher, of the School of Public Health at Imperial and first author of the study, said: “The threat of antimicrobial resistance (AMR) 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.”
He added: “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. Common fungal infections include blights which affect food crops as well as yeast and mould-related infections in humans and livestock, which can be fatal for those with underlying conditions.
Researchers say many drugs used to treat fungal infections in plants and animals are in danger of becoming ineffective and fear the same could happen to those treatments used for human infections.
The findings are reported in a review paper published in a special edition of the journal Science, and highlight an unprecedented rise in emerging strains of fungi which are resistant to common antifungal drugs (AFDs).
Professor Gordon Brown, Director of the MRC Centre for Medical Mycology at the University of Aberdeen, said: “Invasive fungal infections primarily occur in individuals with altered immune function, and there has been a huge increase in these infections over the last few decades as a result of modern medical interventions and HIV/AIDS. These infections have some of the highest mortality rates of any infectious disease, often exceeding 50%.
“This review highlights the huge increase in resistance to many of these drugs around the world, driven in part through commercial use in agriculture. Given the high rates of mortality of these infections, these disturbing trends suggest that even our limited ability to treat these diseases is being severely compromised. We are also seeing the rise of new multidrug resistant fungal pathogens such as Candida auris, for which there are limited therapeutic options.”
The MRC Medical Mycology Centre was set up in April 2016 to tackle the major challenges we face in this field by facilitating innovative interdisciplinary research and training to advance our understanding of fungal pathogenesis and host immunity, and to help improve the diagnosis, prevention and treatment of fungal diseases.
Crop-destroying fungi are thought to account for a loss of 20% of global crop yields each year, and the direct threat to human health is increasingly significant. Researchers estimate the number of human deaths from fungal diseases – often affecting those with weakened immune systems – now exceeds those from malaria and breast cancer, and is comparable to numbers of those caused by tuberculosis and HIV.
The work was supported by the MRC, the Natural Environment Research Council (NERC) and the Biotechnology and Biological Sciences Research Council (BBSRC).