Abstract Title
DETECTION OF VARIOUS A(H5N1) CLADE 2.3.4.4b GENOTYPES FROM WILD WATERFOWL IN THE US MISSISSIPPI MIGRATORY FLYWAY
Abstract
Eurasian (EA)-lineage HPAI A(H5), originating from Goose/Guangdong/1/96 viruses, poses a significant threat to animal and public health. Since their detection in the U.S. in 2021, EA-lineage A(H5) 2.3.4.4b has been identified in all 50 states, affecting multiple wild and domesticated species with spillovers to humans. To determine the continuing threat to animal and human health, active surveillance was conducted to identify and genetically characterize circulating A(H5N1) viruses in the natural reservoir. Cloacal swabs were collected from wild waterfowl in Wisconsin and Ohio, USA, from Autumn 2023 to Summer 2024 and screened for IAV using rRT-PCR, with A(H5N1) 2.3.4.4 confirmation for IAV positives. Virus isolation was attempted for all 19 A(H5N1) positive samples, resulting in 4 isolates that were sequenced via next-generation sequencing for phylogenetic analysis and amino acid sequence analysis. Of the 1591 samples tested, 23.9% (381) were positive for IAV, with 1.2% (19) confirmed as A(H5N1) 2.3.4.4b. GenoFLU genotyping revealed three distinct genotypes, including a novel one, harboring EA-lineage HA, NA, MP, and NS genes, while carrying American am19 PB2, am12 PB1, am1 PA, and am1.3 NP genes. Mutation markers linked to enhanced polymerase activity and reduced antiviral susceptibility were also identified among all the detected isolates. The detection of various genotypes along with a novel reassorted EA-lineage A(H5N1) 2.3.4.4b among waterfowl species highlights their role in evolution of the IAVs important for animal and public health and warrants the need for ongoing surveillance in this natural reservoir to better understand the risks to animal and public health.
Co-Author(s)
MJ Jahid1, L Kubatko2, AS Bowman1, and JM Nolting1
The Ohio State University, Departments of Veterinary Preventive Medicine1 and Statistics2, Columbus, OH, USA
Abstract Category
Notable outbreaks, field and molecular epidemiology, and surveillance in wild birds