title: Dynamics of virus shedding and antibody responses in influenza A virus-infected feral swine.
abstract: Given their free-ranging habits, feral swine could serve as reservoirs or spatially dynamic 'mixing vessels' for influenza A virus (IAV). To better understand virus shedding patterns and antibody response dynamics in the context of IAV surveillance amongst feral swine, we used IAV of feral swine origin to perform infection experiments. The virus was highly infectious and transmissible in feral swine, and virus shedding patterns and antibody response dynamics were similar to those in domestic swine. In the virus-inoculated and sentinel groups, virus shedding lasted ≤ 6 and ≤ 9 days, respectively. Antibody titres in inoculated swine peaked at 1 : 840 on day 11 post-inoculation (p.i.), remained there until 21 days p.i. and dropped to < 1 : 220 at 42 days p.i. Genomic sequencing identified changes in wildtype (WT) viruses and isolates from sentinel swine, most notably an amino acid divergence in nucleoprotein position 473. Using data from cell culture as a benchmark, sensitivity and specificity of a matrix gene-based quantitative reverse transcription-PCR method using nasal swab samples for detection of IAV in feral swine were 78.9 and 78.1 %, respectively. Using data from haemagglutination inhibition assays as a benchmark, sensitivity and specificity of an ELISA for detection of IAV-specific antibody were 95.4 and 95.0 %, respectively. Serological surveillance from 2009 to 2014 showed that ∼7.58 % of feral swine in the USA were positive for IAV. Our findings confirm the susceptibility of IAV infection and the high transmission ability of IAV amongst feral swine, and also suggest the need for continued surveillance of IAVs in feral swine populations.
authors: Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MI, USA.
authors: Hailiang
authors: H
authors: Sun
authors: Mississippi Field Station, National Wildlife Research Center, Wildlife Services, Animal and Plant Health Inspection Service, US Department of Agriculture, Mississippi State, MI, USA.
authors: Fred L
authors: FL
authors: Cunningham
authors: Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MI, USA.
authors: Jillian
authors: J
authors: Harris
authors: Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MI, USA.
authors: Yifei
authors: Y
authors: Xu
authors: Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MI, USA.
authors: Li-Ping
authors: LP
authors: Long
authors: Mississippi Field Station, National Wildlife Research Center, Wildlife Services, Animal and Plant Health Inspection Service, US Department of Agriculture, Mississippi State, MI, USA.
authors: Katie
authors: K
authors: Hanson-Dorr
authors: National Wildlife Research Center, Wildlife Services, Animal and Plant Health Inspection Service, US Department of Agriculture, Fort Collins, CO, USA.
authors: John A
authors: JA
authors: Baroch
authors: Mississippi Field Station, National Wildlife Research Center, Wildlife Services, Animal and Plant Health Inspection Service, US Department of Agriculture, Mississippi State, MI, USA.
authors: Paul
authors: P
authors: Fioranelli
authors: US Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife Services, Fort Collins, CO, USA.
authors: Mark W
authors: MW
authors: Lutman
authors: Viral Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, MD, USA.
authors: Tao
authors: T
authors: Li
authors: US Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife Services, Fort Collins, CO, USA.
authors: Kerri
authors: K
authors: Pedersen
authors: National Wildlife Research Center, Wildlife Services, Animal and Plant Health Inspection Service, US Department of Agriculture, Fort Collins, CO, USA.
authors: Brandon S
authors: BS
authors: Schmit
authors: Department of Pathobiology and Population Medicine, College of Veterinary Medicine, Mississippi State University, Mississippi State, MI, USA.
authors: Jim
authors: J
authors: Cooley
authors: Viral Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, MD, USA.
authors: Xiaoxu
authors: X
authors: Lin
authors: Viral Diseases Branch, Walter Reed Army Institute of Research, Silver Spring, MD, USA.
authors: Richard G
authors: RG
authors: Jarman
authors: National Wildlife Research Center, Wildlife Services, Animal and Plant Health Inspection Service, US Department of Agriculture, Fort Collins, CO, USA.
authors: Thomas J
authors: TJ
authors: DeLiberto
authors: Department of Basic Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MI, USA.
authors: Xiu-Feng
authors: XF
authors: Wan
mesh_terms: D000818:Animals; D000835:Animals, Wild / Q000097:blood / Q000276:immunology / Q000821:virology*; D000914:Antibodies, Viral / Q000097:blood*; D053122:Influenza A Virus, H3N2 Subtype / Q000235:genetics / Q000276:immunology / Q000502:physiology*; D009976:Orthomyxoviridae Infections / Q000097:blood / Q000175:diagnosis / Q000662:veterinary* / Q000821:virology; D013552:Swine; D013553:Swine Diseases / Q000097:blood / Q000175:diagnosis / Q000821:virology*; D017201:Virus Shedding
chemical_list: D000914:Antibodies, Viral