Hospital wastewater-based surveillance as an early-warning system for toxigenic <i>Vibrio cholerae</i> : first detection, isolation, characterization, and traceback investigation in Beijing, China

was successfully isolated from the wastewater sample and identified as the O1 Ogawa serotype. Whole-genome sequencing and comparative genomic analysis revealed that the isolate was closely related to locally circulating strains but clearly distinct from the seventh pandemic lineage, suggesting its link to indigenous transmission chains. In addition, we immediately initiated a comprehensive and multi-source traceback investigation upon detection of this positive signal, integrating clinical, environmental, and epidemiological data. This case highlights the early-warning and situational-awareness value of wastewater surveillance in detecting emerging pathogens and emphasizes its indispensable role in infectious disease prevention and control systems, providing a scientific basis for timely public health decision-making.