The Growing Threat of Fungal Infections: Scientists on the Hunt for Deadly Pathogens

The Dangers of Fungal Infections: Recognizing the Threat and the Need for Better Treatment

The Underrated Menace

The first tray of yellow-lidded specimen jars holds chunks of flesh – lung, perhaps, or muscle – some cerebrospinal fluid and another liquid, possibly from a brain abscess. The second holds a rainbow of colourful fungi, cultivated from those specimens.

One growth is green and fluffy, like something you would find in a sharehouse fridge – penicillium, maybe. Another is a dark grey or brown, like animal fur. There are bright white fuzzballs and blackish blobs. One growth leaches red into the medium it sits in.

Climate Change and the Rising Threat

Fungal pathogens come from all over Australia to a renowned laboratory in Adelaide, called the National Mycological Reference Centre, for identification. Mycologists are on the lookout for new pathogens, which are starting to spread more because of climate change and can be deadly in the absence of effective antifungal drugs.

They work under biohazard signs, sorting specimens and growing colonies on petri dishes to slice off and put under a microscope. There’s a fascinating library of mycology books, a DNA sequencer, and a reference collection with numerous vials, from azole-resistant Aspergillus to Zygomycetes.

Understanding the Outbreaks

Dr. Sarah Kidd, the head of the National Mycological Reference Centre, was interested in Cryptococcus gattii, a fungus that lives in eucalyptus trees and infects koalas, before she moved to Canada. Serendipitously, a C gatti outbreak occurred in Vancouver while she was there. The appearance of the fungus associated with Australia in Canada was a mystery, possibly linked to changing global temperatures and mutations.

While these mutations are worrisome, Kidd states that it’s “certainly not a good thing… but it keeps things interesting.”

From Fiction to Reality

The fascination with fungal pathogens has recently been piqued by the Netflix series The Last of Us, where humans turn into zombies due to a parasitic fungal infection. Dr. Kidd mentions that while the fungal infection Cordyceps portrayed in the series does affect insects, it cannot grow in humans due to our higher body temperature.

She also acknowledges that shows like The Last of Us have greatly contributed to raising awareness about mycology. Previously, people associated mycology primarily with mushrooms or superficial infections, such as skin or toenail fungal infections.

If they find themselves in a host who is susceptible, then they can kill.

The Silent Health Threat

Most people are unaware that fungi can cause life-threatening infections. There are hundreds of fungi species that can affect humans in various ways. According to recent research, approximately 4 million global deaths per year are associated with fungal infections, a number that is likely heavily underreported.

One of the most concerning pathogens at present is Candida auris, which primarily affects immunocompromised patients, people in intensive care, and individuals with cancer or HIV/AIDS. This resilient pathogen can coexist on people until it enters the bloodstream. It is resistant to many existing therapies and can easily spread between individuals, similar to superbugs.

Dr. Megan Lenardon, a microbiologist, explains that these fungal pathogens, known as “opportunistic invasive” pathogens, do not harm healthy individuals but can be fatal for susceptible hosts.

The Urgent Need for Action

The World Health Organization (WHO) has identified four fungal pathogens, including Cryptococcus neoformans, Candida auris, Aspergillus fumigatus, and Candida albicans, as “critical” among the biggest threats to public health. The limited availability of antifungal medicines, the expanding reach of fungal diseases due to global warming and international travel, and the growing resistance of these pathogens to treatment are alarming concerns highlighted by the WHO.

Dr. Lenardon points out that fungi have long been overlooked in infectious disease research. While millions of people suffer from thrush infections caused by Candida species, these fungal infections can become invasive and spread through the organs and bloodstream.

The Call for Action

Currently, there are no imminent vaccines or preventive treatments for fungal infections. However, experts and researchers, such as those at the National Mycological Reference Centre in Adelaide, are dedicating their efforts to screening for infections, implementing necessary precautions, and developing specialized tests and treatments.

Australian experts, including Dr. Sarah Kidd, are raising awareness of the need for better understanding and response to fungal infections. While the situation in Australia is relatively stable, the increasing cases and the emergence of new fungal threats necessitate proactive measures to prevent a future outbreak.