Wastewater epidemiology for Northern Ireland

Overview

During the COVID-19 pandemic, Northern Ireland needed a way to monitor infection trends at community scale, including signals that might not be visible through clinical testing alone. Wastewater offered a practical solution: a single sample could capture a pooled signal from symptomatic, asymptomatic and pre-symptomatic infection across a whole catchment.

BioSeer's founding team thus built and delivered the Northern Ireland SARS-CoV-2 wastewater surveillance programme for the Department of Health and public-health partners. The programme connected field sampling, viral detection, genomic surveillance, environmental chemistry and geospatial reporting into a single operational workflow.

The result was a regional surveillance capability that could detect SARS-CoV-2 and other key clinical pathogens (e.g. influenza A, Respiratory Syncytial Virus, Norovirus) in wastewater, track changes across catchments, support variant intelligence and translate complex laboratory outputs into decision-facing public-health evidence.

The Challenge

Wastewater surveillance is powerful, but the signal is technically demanding. Viral RNA is often present at low levels. Wastewater can contain inhibitors that affect molecular assays. Raw concentrations can also be distorted by dilution, industrial inputs and catchment-to-catchment variation.

The programme needed to move beyond simple detection. Public-health teams required results that could be compared across places, followed over time and interpreted alongside clinical and population-level data.

What we did — the integrated approach

We built Northern Ireland's wastewater surveillance programme into a national capability, with samples from 31 sites collected up to four times a week and results returned routinely within 24 hours — and within 8 hours when a situation demanded it. What made the programme work was running three disciplines together, under one roof, rather than shipping samples between specialist labs.

• The chemistry made the data comparable. Raw wastewater data must be corrected before it can be interpreted confidently. The programme used ammonia-based normalisation to support correction for dilution and population effects, helping convert raw gene-copy measurements into comparable community-level indicators. Environmental chemistry is not an add-on to pathogen surveillance — it is what helps microbiology and genomics become decision-grade evidence.
• The microbiology turned wastewater into early warning. We developed a high-throughput, automated workflow that concentrates pathogens, removes inhibitors and quantifies targets quickly, reliably and at scale. Because pathogens can be detected in wastewater before they appear clearly in clinical testing, this approach can provide advance warning, typically 4–17 days ahead of clinical detection.
• The genomics turned detection into variant intelligence. Sequencing and bioinformatic analysis enabled detection of known SARS-CoV-2 variants, and other key clinical pathogens, in wastewater and supported tracking of how variant composition changed over time. Over the programme we sequenced thousands of wastewater samples for SARS-CoV-2 alone and developed our own bioinformatic methods to spot variant-defining mutations earlier than conventional approaches could.
• Reporting closed the loop. Results were mapped to drainage areas, Health and Social Care Trusts and local government geographies. Weekly outputs were shared through spatial dashboards and regular reporting, helping public-health partners view trends across Northern Ireland and compare wastewater signals with clinical and population-level data.

Why it matters now

The Northern Ireland programme showed how wastewater surveillance can become a practical, scalable and privacy-preserving tool for public-health intelligence. The same integrated model can now be applied beyond SARS-CoV-2 to support broader biosurveillance — including respiratory viruses, enteric pathogens, antimicrobial resistance, emerging variants and pathogen-agnostic monitoring.

For BioSeer, this case study demonstrates the value of bringing microbiology, genomics and environmental chemistry together in one workflow. Most laboratories specialise. BioSeer integrates.