IAV-S — Virus and transmission

Influenza A virus in swine (IAV-S) is a respiratory disease that can cause significant disease in swine operations.1 IAV-S can circulate year-round with peak incidence occurring during cooler and damp weather months.2

The virus is most stable at cooler/cold temperatures, in water, and in environments with mild-to-moderate humidity (where water is able to exist more as a 'droplet'). These conditions promote the transmission of IAV-S through a swine population.3,4

Signs of IAV-S can include fever, coughing, lethargy, discharge from the nose or eyes, labored breathing or ‘thumping’, and going off feed.5,6 While mortality is relatively low, IAV-S can be a contributing factor of increased mortality, productivity losses, and reproductive inefficiency.1,5,6 The virus is endemic in most herds and is easily transmitted from infected to susceptible animals.7

Introduction to IAV-S

References: 1. Vincent AL, Perez DR, Rajao D, et al. Influenza A virus vaccines for swine. Vet Microbiol. 2017;206:35–44. doi:10.1016/j.vetmic.2016.11.026. Epub 2016 Nov 24. 2. Kaplan BS, DeBeauchamp J, Stigger-Rosser E, et al. Influenza virus surveillance in coordinated swine production systems, United States. Emerg Infect Dis. 2015;21(10):1834–1836. 3. Mastin A, Alarcon P, Pfeiffer D, et al. Prevalence and risk factors for swine influenza virus infection in the English pig population. PLoS Curr. 2011;3:RRN1209. 4. Romagosa A, Allerson M, Gramer M, et al. Vaccination of influenza A virus decreases transmission rates in pigs. Vet Res. 2011;42:120. 5. Janke BH. Influenza A virus infections in swine: pathogenesis and diagnosis. Vet Pathol. 2014;51(2):410–426. 6. Er C, Lium B, Tavornpanich S, et al. Adverse effects of Influenza A(H1N1)pdm09 virus infection on growth performance of Norwegian pigs—a longitudinal study at a boar testing station. BMC Vet Res. 2014;10:284. doi:10.1186/s12917-014-0284-6. 7. Diaz A, Perez A, Sreevatsan S, et al. Association between influenza A virus infection and pigs subpopulations in endemically infected breeding herds. PLoS ONE. 2015;10(6):e0129213. doi:10.1371/journal.pone.0129213.