Mouldy Planet: Fungi and One Health

Abstract

Prevention of diseases caused by pathogenic fungi exemplifies the need for a One Health approach because a fungal species can cause similar disease in humans and animals and can survive long in the environment. This case study of coccidioidomycosis (valley fever) illustrates the power of integrative surveillance for One Health. Fungi belong to a taxonomically distinctive group of organisms that are among the most diverse, widely distributed and metabolically versatile organisms on earth. Physically, fungi range in size from microscopic yeasts, visible mould with colourful spores, and mushrooms, which may be larger than a human palm. Through their genetic profile and heterotrophy, fungi are more related to animals than to plants. Fungi can cause disease in humans, animals and plants, and they produce infectious forms such as lightweight spores, which can survive long in natural environments. Therefore, many diseases caused by pathogenic fungi are better understood and controlled through a transdisciplinary One Health approach. Fungi produce antibiotics such as penicillin, and they are also capable of developing resistance to many medications used to treat infections, making them a major threat to global health. This case study focuses on coccidioidomycosis (valley fever), an illness that develops from inhaling spores of the fungus Coccidioides imitis or Coccidioides posadasii , which are commonly found in soils of the south-western USA and in Central and South America, where the disease has been long recognized as a threat. Communities of people, pets and farm animals inhabiting periodically dry environmental conditions are particularly vulnerable, and investigators have suggested that the current incidence of the disease and the geographical expansion of zones of vulnerability are linked to climate change. 1 Improved understanding of the One Health context of valley fever should inform public communication strategies for preventing the disease.