Abstract
Avian influenza surveillance in wild birds is paramount for the timely detection of HPAI strains. Since water plays a key role in virus transmission, monitoring water bodies where waterfowl congregate represents an appealing opportunity to improve surveillance. Traditional testing methods, such as (ultra)filtration and precipitation, have limitations including the need for pumping equipment and the identification of sample volume representative of the water body. In contrast, passive samplers (PS) provide a cost-effective solution that requires no specialized tools and skills.
This study screened nine materials for their capacity to adsorb AIV in brackish and freshwater. The most effective ones detected down to 103 AIV GC/L, and were thus employed for laboratory protocols optimization and for assessing their use as PS after 3h, 24h, 7d deployment. Cotton, nylon and nitrocellulose showed the best performance, being able to adsorb AIV at all deployment times, with highest recovery after 24h. However, 3h and 7d deployment can be considered effective, assuming that PS are exposed to virus shedding in the environment at any time. Accordingly, end-users can select the most convenient option based on the sampling regimen. Laboratory data showed that part of the virions were adsorbed irreversibly, suggesting that PS can be effective even when the virus is washed away (e.g. tides, rain). Field validation of PS in three different wetlands, corroborated laboratory data, confirming their efficacy after 3h-7d deployment, also under heavy rain. AIV subtypes detected in PS aligned with epidemiological data on wild birds from the same areas.
This study screened nine materials for their capacity to adsorb AIV in brackish and freshwater. The most effective ones detected down to 103 AIV GC/L, and were thus employed for laboratory protocols optimization and for assessing their use as PS after 3h, 24h, 7d deployment. Cotton, nylon and nitrocellulose showed the best performance, being able to adsorb AIV at all deployment times, with highest recovery after 24h. However, 3h and 7d deployment can be considered effective, assuming that PS are exposed to virus shedding in the environment at any time. Accordingly, end-users can select the most convenient option based on the sampling regimen. Laboratory data showed that part of the virions were adsorbed irreversibly, suggesting that PS can be effective even when the virus is washed away (e.g. tides, rain). Field validation of PS in three different wetlands, corroborated laboratory data, confirming their efficacy after 3h-7d deployment, also under heavy rain. AIV subtypes detected in PS aligned with epidemiological data on wild birds from the same areas.
Co-Author(s)
Valentina Panzarin1, Marika Crimaudo1, Sabrina Marciano1, Paola Berto2, Silvia Bofill Mas3, Marta Rusiñol3, Francesco Bonfante1, Eva Mazzetto1, Andrea Fortin1, Alessio Bortolami1, Francesco Pascoli2, Diletta Fornasiero1, Calogero Terregino1
1EU/WOAH/National Reference Laboratory for Avian Influenza and Newcastle Disease, FAO Reference Centre for Animal Influenza and Newcastle Disease, Division of Comparative Biomedical Sciences, Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe), 35020 Legnaro (Padua), Italy
2Fish Virology Laboratory, Division of Comparative Biomedical Sciences, Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe), 35020 Legnaro (Padua), Italy
3Laboratory of Viruses Contaminants of Water and Food, Secció de Microbiologia, Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Universitat de Barcelona (UB), 08028 Barcelona, Spain
Abstract Category
Diagnostics, vaccination, or other mitigation strategies for poultry and wildlife