Abstract Title
Validation of Filter Strips for Avian Influenza Virus Antibody Detection: Comparative Analysis with Serum Across NP, H5, and H7 Targets
Abstract
The detection of antibodies against avian influenza virus (AIV) is a key approach for AIV surveillance in wild bird populations. While serum samples are traditionally used for detecting anti-AIV antibodies, they pose logistical challenges for large-scale surveillance, especially in remote areas, small-sized species, or situations where serum collection is not feasible, such as in hunter-harvested samples. This study evaluates the use of Nobuto filter strips as an alternative to serum for detecting antibodies against AIV nucleoprotein (NP), H5, and H7 targets. We tested paired serum and filter strip samples using the commercially available IDEXX AI MultiS Screen Ab test and in-house competitive ELISAs developed at the National Centre for Foreign Animal Disease (NCFAD). A strong correlation (ρ = 0.77) was found between serum and filter strips for NP detection with the IDEXX ELISA, while weaker correlations were observed for NCFAD’s NP ((ρ = 0.58) and H5 (ρ = 0.65) assays. Threshold optimization using the Youden index significantly improved diagnostic performance for NP (sample-to-negative (S/N) <0.7708 for IDEXX and percent inhibition (PI) >39.56 for NCFAD) and H5 (PI >20.37), although challenges remained for H7 detection even after optimization. Storage conditions were found to affect performance, with frozen samples yielding more positive detections than room temperature samples. These results demonstrate the potential of Nobuto filter strips as a practical and informative alternative sample type for AIV serologic surveillance provided optimal storage and threshold adjustments are implemented.
Co-Author(s)
Jolene A. Giacinti1, Ishraq Rahman2, Jordan Wight2, Hannah Lewis3, Liam Taylor4, Jennifer F. Provencher1, Robert Ronconi5, Yohannes Berhane6, Wanghong Xu6, Dmytro Zhmendak6, Sailendra N. Sarma1, Christopher M. Sharp3, Kathryn E. Hargan2, Joshua Cunningham4, Andrew S. Lang2
1.Ecotoxicology and Wildlife Health Division, Science and Technology Branch, Environment and Climate Change Canada, Government of Canada, Ottawa, Ontario, Canada
2.Department of Biology, Memorial University of Newfoundland, St. John’s, Newfoundland and Labrador, Canada
3.Ontario Region Wildlife and Habitat Assessment Section, Canadian Wildlife Service, Environment and Climate Change Canada, Government of Canada, Ottawa, Ontario, Canada
4.Biology Department, Bowdoin College, Brunswick, Maine, United States
5.Atlantic Region Wildlife and Habitat Assessment Section, Canadian Wildlife Service, Environment and Climate Change Canada, Government of Canada, Sackville, New Brunswick, Canada
6.National Centre for Foreign Animal Disease, Canadian Food Inspection Agency, Government of Canada, Winnipeg, Manitoba, Canada
Abstract Category
Diagnostics, vaccination, or other mitigation strategies for poultry and wildlife