TY - JOUR

T1 - The role of gilts in transmission dynamics of swine influenza virus and impacts of vaccination strategies and quarantine management

AU - Ryt-Hansen, Pia

AU - Nielsen, Henriette Guldberg

AU - Sørensen, Simon Smed

AU - Larsen, Inge

AU - Kristensen, Charlotte Sonne

AU - Larsen, Lars Erik

N1 - Publisher Copyright: © 2022, The Author(s).

PY - 2022

Y1 - 2022

N2 - Background: Along with an expanding global swine production, the commercial housing and management of swine herds, provide an optimal environment for constant circulation of swine influenza virus (swIAV), thereby challenging farmers and veterinarian in determining optimal control measures. The aim of this study was to investigate the role of gilts in the swIAV transmission dynamics, and to evaluate the impact of different control measures such as quarantine and gilt vaccination. Methods: The study was conducted as a cross-sectional study in ten Danish sow herds, including five swIAV vaccinated and five unvaccinated herds. Blood- and nasal swab samples of gilts, first parity sows and their piglets were collected at different stages in the production system (quarantine in/out, mating, gestation and farrowing) and analyzed for the presence of swIAV and swIAV antibodies. Associations between the detection of swIAV, seroprevalence, antibody levels, sow and gilt vaccination strategy and quarantine biosecurity were thereafter investigated to identify possible risk factors for swIAV introductions and persistence within the herds. Results: Nine of the ten herds of the study had swIAV circulation and swIAV was detected in the quarantine, mating- and farrowing unit. The prevalence of seropositive gilts and first parity sows was significantly higher in the vaccinated herds, but swIAV was still present in nasal swabs from both gilts, first parity sows and piglets in these herds. Quarantine gilt vaccination and all-in/all-out management resulted in a significant reduction of swIAV positive gilts at the end of the quarantine period. Conclusion: The results underline that herd vaccination and/or quarantine facilities are crucial to avoid swIAV introductions into sow herds.

AB - Background: Along with an expanding global swine production, the commercial housing and management of swine herds, provide an optimal environment for constant circulation of swine influenza virus (swIAV), thereby challenging farmers and veterinarian in determining optimal control measures. The aim of this study was to investigate the role of gilts in the swIAV transmission dynamics, and to evaluate the impact of different control measures such as quarantine and gilt vaccination. Methods: The study was conducted as a cross-sectional study in ten Danish sow herds, including five swIAV vaccinated and five unvaccinated herds. Blood- and nasal swab samples of gilts, first parity sows and their piglets were collected at different stages in the production system (quarantine in/out, mating, gestation and farrowing) and analyzed for the presence of swIAV and swIAV antibodies. Associations between the detection of swIAV, seroprevalence, antibody levels, sow and gilt vaccination strategy and quarantine biosecurity were thereafter investigated to identify possible risk factors for swIAV introductions and persistence within the herds. Results: Nine of the ten herds of the study had swIAV circulation and swIAV was detected in the quarantine, mating- and farrowing unit. The prevalence of seropositive gilts and first parity sows was significantly higher in the vaccinated herds, but swIAV was still present in nasal swabs from both gilts, first parity sows and piglets in these herds. Quarantine gilt vaccination and all-in/all-out management resulted in a significant reduction of swIAV positive gilts at the end of the quarantine period. Conclusion: The results underline that herd vaccination and/or quarantine facilities are crucial to avoid swIAV introductions into sow herds.

KW - Biosecurity

KW - Enzootic infections

KW - Gilts

KW - Management

KW - Quarantine

KW - Swine influenza A virus

KW - Vaccination

U2 - 10.1186/s40813-022-00261-2

DO - 10.1186/s40813-022-00261-2

M3 - Journal article

C2 - 35513878

AN - SCOPUS:85129591610

VL - 8

JO - Porcine Health Management

JF - Porcine Health Management

SN - 2055-5660

IS - 1

M1 - 19

ER -