Ryt-Hansen Pia, Nielsen Henriette Guldberg, Sørensen Simon Smed, Larsen Inge, Kristensen Charlotte Sonne, Larsen Lars Erik
Department of Veterinary and Animal Sciences, University of Copenhagen, Grønnegårdsvej 2, 1870, Frederiksberg C, Denmark.
Danish Pig Research Centre, SEGES, Agro Food Park 15, 8200, Aarhus, Denmark.
Porcine Health Manag. 2022 May 5;8(1):19. doi: 10.1186/s40813-022-00261-2.
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.
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.
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.
The results underline that herd vaccination and/or quarantine facilities are crucial to avoid swIAV introductions into sow herds.
随着全球生猪生产规模的扩大，生猪的商业化饲养和管理为猪流感病毒（swIAV）的持续传播提供了理想环境，这给养殖户和兽医在确定最佳防控措施方面带来了挑战。本研究的目的是调查后备母猪在swIAV传播动态中的作用，并评估不同防控措施（如隔离和后备母猪疫苗接种）的影响。
本研究作为一项横断面研究，在丹麦的10个母猪群中进行，其中包括5个接种了swIAV疫苗的猪群和5个未接种疫苗的猪群。在生产系统的不同阶段（隔离进出、配种、妊娠和产仔）采集后备母猪、初产母猪及其仔猪的血液和鼻拭子样本，分析其中swIAV和swIAV抗体的存在情况。随后研究swIAV检测、血清阳性率、抗体水平、母猪和后备母猪疫苗接种策略以及隔离生物安全之间的关联，以确定猪群中swIAV引入和持续存在的可能风险因素。
本研究的10个猪群中有9个存在swIAV传播，在隔离、配种和产仔单元均检测到swIAV。接种疫苗的猪群中，血清阳性后备母猪和初产母猪的比例显著更高，但这些猪群中后备母猪、初产母猪和仔猪的鼻拭子中仍存在swIAV。隔离后备母猪疫苗接种和全进全出管理在隔离期结束时显著降低了swIAV阳性后备母猪的数量。
结果强调，猪群疫苗接种和/或隔离设施对于避免swIAV引入母猪群至关重要。
