Wastewater surveillance as an early warning system for fungal pathogens

Wastewater-based surveillance (WBS) involves the routine molecular and microbiological analysis of municipal sewage to track pathogen circulation across communities, without relying on individual clinical testing. The COVID-19 pandemic established WBS as an effective early warning system, with SARS-CoV-2 detection preceding clinical case surges by 4–14 days. These findings prompted investment in viral and bacterial wastewater monitoring infrastructure [1–3]. In contrast, invasive fungal infections cause approximately 2.5 million deaths annually (more than tuberculosis and malaria combined) yet receive disproportionately limited research investment and public health prioritisation [4]. Hospital outbreaks caused by drug-resistant Candida species are increasingly common as fungi adapt to human body temperatures, healthcare environments, and antifungal pressure [4–6]. Despite the World Health Organization’s (WHO) designation of priority fungal pathogens requiring urgent surveillance innovation, this burden has not yet translated into public health action [5].

The capacity to build coordinated surveillance systems is well established, as evidenced by the global polio monitoring and antibiotic resistance monitoring in bacteria, which evolved from fragmented national initiatives into a globally coordinated infrastructure [1]. Climate change, expanding immunocompromised populations and paucity of antifungal therapeutics create ecological and clinical conditions favourable to the emergence and spread of fungal pathogens; however, the development of a coordinated surveillance strategy to detect fungal outbreaks lags behind this evolving threat [6]. Here, we examine why existing clinical surveillance frameworks fail for fungi, review evidence for Candida WBS, and identify the key research priorities to address this gap.