Healthcare wastewater surveillance: methodological considerations for sampling, feasibility, and implementation

Wastewater surveillance (WWS) at healthcare facilities is a nascent field with knowledge gaps in the feasibility of conducting such surveillance at this specialized facility type, and for how to best implement and interpret wastewater (WW) data. WWS was piloted at skilled nursing facilities, including conducting tracer studies, optimization of a low-flow strainer for autosampler WW collection, and preliminary testing of a WW access survey. An expanded WW access survey with collaboration from additional partners was distributed to 16 post-acute/long-term care facilities. The lessons learned obtained through the pilot 'use cases' demonstrated minimal clogging and consistent collection of WW using a low-flow strainer (±0.36 L) and tracer studies highlighted the importance to confirm facility effluent source with an average visual dye detection between 1.5 and 2.5 min from the toilet flush. The expanded WW access survey assessed the feasibility of WWS regarding physical onsite manhole access, safety aspects, effluent flow, and other factors, where 75% (12 of 16) of surveyed facilities demonstrated feasibility. Healthcare facility-level WWS includes specialized methodological approaches prior to implementation to achieve the intended public health impact. These considerations support the continued overall goal of detecting emerging biological public health threats at healthcare facilities using WWS.