Out-of-Control Transmission Mechanisms of Pathogens in Urban Sewage Systems Under Extreme Climate Events and Emergency Prevention

Abstract:

Extreme climate events (e.g., heavy rainfall, floods, heatwaves) have become more frequent and intense due to global warming, severely disrupting urban sewage systems and triggering out-of-control transmission of waterborne pathogens (e.g., Escherichia coli, Salmonella, norovirus). This study integrates environmental microbiology, pathogen detection technology, and AI-based sewage system modeling to explore how extreme climates damage sewage infrastructure, alter pathogen survival and proliferation, and enhance transmission risks. Field investigations were conducted in 12 flood-affected and 8 heatwave-impacted cities (2021–2023) to monitor sewage overflow, pathogen concentrations, and disease outbreaks. Innovative methods (digital PCR, metagenomic sequencing) were used to quantify and identify pathogenic strains, while AI models predicted sewage system failure and pathogen spread. Results show that heavy rainfall increases sewage overflow by 300–500%, raising E. coli concentrations in surface water to 10⁵ CFU/100mL—100-fold higher than normal. Heatwaves (≥35°C) reduce sewage treatment efficiency by 40%, increasing norovirus discharge by 250%. This study proposes emergency  strategies (real-time monitoring, infrastructure reinforcement, rapid disinfection) to mitigate pathogen transmission risks under extreme climates.