Vieira Antonio R, Hofacre Charles L, Smith John A, Cole Dana
College of Veterinary Medicine, Department of Large Animal Medicine, University of Georgia, Athens, GA 30602, USA.
Avian Dis. 2009 Mar;53(1):55-62. doi: 10.1637/8364-051608-Reg.1.
As highly pathogenic avian influenza H5N1 virus continues to circulate in the world, poultry farm biosecurity and timely reporting of morbidity and mortality among commercial poultry farms in the United States are major concerns. To assess the vulnerability of poultry farms to the introduction and spread of a highly infectious pathogen, such as the currently circulating H5N1 influenza virus, a survey was administered to growers in two counties in Georgia representing areas of low and high poultry densities. Survey questions regarding horizontal contacts and management were sent to commercial broiler and breeder-layer chicken producers. Responses were used to estimate and compare contact rates and patterns between the two regions. The distribution of high-risk visitors (i.e., those going inside the poultry houses) to poultry farms did not vary significantly between growers in counties with high and low poultry densities or between breeder-layer and broiler growers. Compared with broiler producers in the county with high poultry density, broiler growers in the county with low poultry density were more likely to hire non-family employees to help with poultry management (62% vs. 17%; P = 0.001) and assist other growers with their poultry (31% vs. 6%; P = 0.025). Use of contracted litter services was significantly higher (P = 0.019) among broiler growers in the poultry-dense county (40%) compared with the low-density county (6%). Compared with broiler growers, breeder-layer producers also were significantly more likely to hire non-family employees to help on the farm (53% vs. 17%; P = 0.008). Poultry growers in the highly poultry-dense county were more likely to have a public road or field receiving poultry litter within a quarter mile of their poultry houses, compared with those in the lower density county. Data obtained in this study support the observations of published poultry disease outbreak investigations and highlight the differences in farm vulnerability to disease introduction within areas of different poultry densities and management practices.
由于高致病性禽流感H5N1病毒仍在全球传播，美国商业家禽养殖场的生物安全以及及时报告发病率和死亡率成为主要关注点。为评估家禽养殖场对高传染性病原体（如当前传播的H5N1流感病毒）传入和传播的脆弱性，对佐治亚州两个县的养殖者进行了一项调查，这两个县分别代表家禽密度低和高的地区。关于横向接触和管理的调查问题被发送给商业肉鸡和种鸡生产者。调查结果用于估计和比较两个地区的接触率和模式。高风险访客（即进入禽舍的人员）在家禽密度高和低的县的养殖者之间，以及种鸡和肉鸡养殖者之间的分布没有显著差异。与家禽密度高的县的肉鸡生产者相比，家禽密度低的县的肉鸡养殖者更有可能雇佣非家庭成员来协助家禽管理（62%对17%；P = 0.001），并帮助其他养殖者管理家禽（31%对6%；P = 0.025）。家禽密度高的县的肉鸡养殖者使用合同垫料服务的比例（40%）显著高于密度低的县（6%）（P = 0.019）。与肉鸡养殖者相比，种鸡生产者雇佣非家庭成员在农场帮忙的可能性也显著更高（53%对17%；P = 0.008）。与密度较低的县相比，家禽密度高的县的家禽养殖者的禽舍周围四分之一英里内更有可能有公共道路或田地接收家禽粪便。本研究获得的数据支持了已发表的家禽疾病爆发调查结果，并突出了不同家禽密度和管理方式地区的农场对疾病传入的脆弱性差异。
