Environmental surveillance is a promising new strategy for monitoring highly pathogenic avian influenza viruses (HPAIVs) spread by migratory birds. In fall 2024, the British Columbia Ministry of Agriculture and Food successfully deployed a novel surveillance program based on screening sediment specimens from wild bird habitats.
Surveillance was conducted during the fall migration season at seven wetlands in the Greater Vancouver region. Each site was visited bi-weekly between 5 Sept 2024 and 28 Nov 2024. Twelve sediment specimens were collected per site visit (504 total). Specimens were screened for influenza viruses and positives were characterized by targeted genomic sequencing.
We found that:
- Sediment surveillance provides early warning for HPAI incursions and anticipates infection trends in wildlife and poultry (Figure 1).
- Sediment surveillance detects broader AIV diversity than passive wildlife surveillance, which can be used to assess the HPAI risk.
- HPAI H5 viruses detected in sediment were the close relatives of those infecting local wildlife, poultry, and humans (showing that viruses in the environment mirror those currently circulating in animals).
Overall, we found that genomic analysis of wetland sediment can be used to provide early warning for HPAI incursions and situational awareness risk of spillover into poultry.