Episode Summary
Executive Summary: Erin Welsh interviews Dr. Emily Monason about Blight, a book on fungal and fungus-like pathogens, their historical and emerging impacts on humans, animals, crops, and ecosystems. They trace outbreaks like chestnut blight, Candida auris, chytrid fungi, white-nose syndrome, and banana diseases, emphasizing how trade, travel, monoculture, and climate change amplify risk—and how awareness, surveillance, biodiversity, and better regulation offer hope.
Main Topics: Why Blight was written (Priority: 5/5): Monason explains that late blight in tomatoes, the Great Famine potato blight connection, and a scientific paper on emerging fungal threats across species inspired the book. Rise of human fungal infections (Priority: 5/5): The conversation covers why fungal disease has become more visible in humans, including immunocompromise from HIV, transplants, antibiotic-driven microbiome disruption, and the emergence of Candida auris. Animal fungal pandemics (Priority: 5/5): They discuss devastating fungal diseases in frogs and bats, including chytrid fungus, Bsal, and white-nose syndrome, and why these pathogens can spread so destructively. Plant and forest catastrophes (Priority: 5/5): Chestnut blight is used to show how a single fungal pathogen can transform entire ecosystems and eliminate a dominant tree species across regions. Agriculture, monoculture, and bananas (Priority: 4/5): The discussion uses banana diseases TR1 and TR4 to show how monoculture and global trade create vulnerability and why more diverse, resilient farming systems matter. Trade, travel, and regulation gaps (Priority: 4/5): The interview highlights how moving plants, animals, soil, and even people across borders spreads pathogens, while also noting uneven quarantine and inspection systems. Hope through surveillance and biodiversity (Priority: 4/5): Monason argues that awareness, rapid diagnosis, stronger biosecurity, and embracing biodiversity in crops and ecosystems can reduce future fungal threats.
Key Arguments: Fungal diseases are often overlooked because most fungi are beneficial, yet the small fraction that are pathogenic can be devastating across species. Human fungal infections have increased partly because more people are immunocompromised, more patients receive transplants, and antibiotics disrupt microbial balance. Candida auris was alarming because it emerged in multiple regions around the same time, was resistant to many antifungals, and spread within hospitals. Trade and travel move pathogens into naïve populations, where they can cause explosive outbreaks because hosts have little evolved defense. Chestnut blight illustrates how quickly a fungus can transform whole forests and ecological relationships once introduced. Monoculture in agriculture makes crops like bananas highly vulnerable; replacing one susceptible clone with another can simply set up the next epidemic. Biodiversity, crop diversification, and improved regulation are central tools for prevention rather than relying only on treatment after outbreaks begin. Public awareness and early detection matter because once many fungal pathogens establish in an environment, they are extremely difficult to remove.
Data Points: WHO priority fungal pathogens: 19 - Monason notes the World Health Organization’s 2022 announcement of 19 priority fungal pathogens. Year Candida auris became a major concern: 2016 - The CDC issued alerts and the fungus emerged as a recognized hospital threat around this time. Late blight tomato outbreak: 2006 or 2007 - Monason’s interest began with a destructive tomato disease outbreak on the U.S. East Coast. Chestnut tree age at death: 180-something years old - Erin recalls a cross-section of an American chestnut killed by chestnut blight in the early 20th century. Chestnut blight spread timeframe: Within decades - The fungus spread from New York through the Appalachians and eliminated nearly all American chestnuts. Banana soil survival: 10 years or more - TR1 is described as a soil-borne fungus that can persist for a decade or longer. Salamander import restriction list: 200 and 9 (209) species - A regulation eventually barred a list of salamanders known to carry Bsal from entering the U.S.
Pivotal Quotes: "once a disease, you know, so what I learned from that was just that I was writing and I was trying to understand the disease." — Dr. Emily Monason: Explaining how late blight in tomatoes helped inspire the book’s subject matter. "The biggest one... came HIV... and fungal diseases started to rise." — Dr. Emily Monason: Describing the rise of human fungal infections among immunocompromised populations. "once it's here, it's here." — Erin Welsh: Summarizing the problem of hard-to-eradicate environmental fungal pathogens.
Implications: The episode urges listeners to treat fungal disease as a serious biosecurity issue: protect biodiversity, reduce risky trade and monoculture, improve detection and regulation, and recognize that ecosystem health directly shapes future pandemic risk.