Environmental pathogen surveillance in cities without universal piped wastewater infrastructure

Area of Science:

• Environmental science
• Public health
• Microbiology

Background:

• Conventional wastewater surveillance is limited in low- and middle-income countries due to lack of infrastructure.
• Environmental surveillance beyond wastewater treatment plants (WWTPs) offers alternative public health insights.
• Understanding pathogen distribution in various environmental matrices is crucial for exposure assessment.

Purpose of the Study:

• To explore the potential of environmental surveillance beyond conventional wastewater systems.
• To measure pathogen and fecal indicator bacteria concentrations in diverse environmental samples.
• To assess the utility of this approach for public health responses in resource-limited settings.

Main Methods:

• Pathogen, source-tracking markers, and fecal indicator bacteria were measured using multi-parallel RT-qPCR.
• Samples were collected from WWTP influent/effluent, surface discharges, river water, soils, drains, stormwater, and fecal sludges.
• Regression modeling was used to analyze pathogen concentrations in relation to environmental factors like precipitation.

Main Results:

• A wide range of pathogens were detected across all environmental matrices.
• Pathogen concentrations were generally lower in environmental samples compared to WWTP influent.
• Increased precipitation was associated with higher pathogen concentrations in all matrices.

Conclusions:

• Environmental pathogen surveillance is a viable tool for informing public health in cities without comprehensive wastewater services.
• Diverse environmental matrices provide valuable data on pathogen flows and potential exposure routes.
• This approach has broad applications for public health interventions and evaluating control programs.