The potential of wastewater monitoring as a novel surveillance tool for early warning of <i>Bordetella pertussis</i> outbreaks

The prolonged latency period and delayed reporting of clinical surveillance data have led to a sluggish response to <i>Bordetella pertussis</i> outbreaks in China. Wastewater-based surveillance (WBS) provides real-time, cost-effective monitoring of various viruses. To confirm whether this approach can be applied to <i>B. pertussis</i>, 271 patients infected with <i>B. pertussis</i> were enrolled to evaluate the fecal shedding patterns of the bacterium. Concurrently, we collected wastewater samples in a typical northern (Xi’an) and southern city (Nanchang) in China, from September 2023 to July 2024. The concentrations of <i>B. pertussis</i> in the sewage were detected using quantitative polymerase chain reaction (qPCR). Additionally, metagenomic sequencing with pre-enrichment was employed to trace genotypes of <i>B. pertussis</i>. We report that 40.2% of cases tested positive for <i>B. pertussis</i> in fecal samples. Sewage surveillance identified two waves of <i>B. pertussis</i> infection in Xi’an and one wave of <i>B. pertussis</i> outbreak in Nanchang. The concentration of <i>B. pertussis</i> in sewage showed a strong correlation with the dynamics of diagnosed cases. Notably, each peak of sewage <i>B. pertussis</i> concentration occurred 10 days prior to clinical surveillance, underscoring the value of WBS in early warning. Additionally, both clinical and wastewater surveillance demonstrated consistency in the prevalence estimation of <i>B. pertussis</i> infection cases. Finally, relative to clinical surveillance, wastewater sequencing also revealed the same genotypes of <i>B. pertussis</i>. This study presents the first comprehensive analysis of the fecal shedding of <i>B. pertussis</i>, thereby establishing the potential for early detection of <i>B. pertussis</i> outbreaks through WBS.