Wastewater surveillance in emergency departments: a qualitative study examining implementation of a sub-sewershed strategy

Wastewater surveillance for infectious diseases is an approach that generates timely public health information. Although most commonly performed at regional wastewater treatment plants (WWTP), this technology is versatile and can be implemented across a variety of settings. Utilizing a strategic sub-sewershed sampling strategy in emergency departments (EDs) could provide a care-linked, sentinel signal offering rapid geographically-granular insights into infectious disease patterns among patient populations seeking care. In parallel to a separate quantitative pilot of ED-based wastewater surveillance in two California EDs, we used an exploratory qualitative research design to conduct semi-structured interviews with 17 diverse professional stakeholders to explore perceived benefits, challenges, and implementation considerations surrounding ED-based wastewater surveillance. Deidentified interview transcripts were analyzed using thematic analysis, followed by content analysis to describe the distribution of themes across interviews. All 17 participants viewed ED-based wastewater surveillance favorably, citing its potential to identify pathogen trends. While several participants (n=6) felt the approach could be used to show prevalence of unreported conditions, others (n=8) thought it could result in increased testing for specific conditions. However, concerns were raised, with the most frequently cited challenges relating to the perceived difficulty of collecting samples (n=9) and unclear utility for data to inform action plans (n=5). Participants saw utility in conducting ED-based wastewater surveillance and generally regarded this approach as feasible, but noted that support and resources are required to leverage this ED-based, sub-sewershed, wastewater surveillance approach to its fullest potential, including clear action thresholds, stakeholder education, and sustainable resourcing.