Department of Animal Health and Antimicrobial Strategies, National Veterinary Institute, Uppsala, Sweden.
Avian Pathol. 2010 Dec;39(6):525-32. doi: 10.1080/03079457.2010.527923.
The present study was undertaken to investigate the prevalence of ascarid infections in Swedish commercial laying hens in 2004 and 2008 following a recent nationwide change to alternative housing systems but before anthelmintics became available. Also, the influence on prevalence of farm and flock characteristics and management was studied in 2004. The results showed that the overall prevalence was significantly higher in 2008 (38%; n = 64/169) compared with 2004 (24%; n = 44/186) (P = 0.001). Ascarid infections were rare in caged flocks, including furnished (enriched) cages, both years (2.4 to 4.3%), and were significantly more common in non-cage systems in both years (16.7 to 48.6% in 2004, and 28.6 to 77.1% in 2008 depending on the housing system). There was no significant difference in prevalence between hens kept on litter indoors and free-range/organic hens. The absence of a hygiene barrier at the entrance of the house or unit increased the risk of infection (P < 0.001), which suggests that parasite eggs were introduced horizontally to the farms. The risk of infection also increased with the age of equipment used in the barn; for example, the risk increased with an odds ratio of 7.5 (95% confidence interval = 2.3 to 25) when comparing equipment 1 year old with equipment ≥7 years old. The results of this study show that ascarid infections may re-emerge following a change to alternative housing. With the impending ban on conventional battery cages in the member states of the European Union, ascarid infections are likely to increase in importance and efficient control options such as hygiene barriers should be implemented on all farms.
本研究旨在调查 2004 年和 2008 年瑞典商业蛋鸡的蛔虫感染流行情况，这是在最近全国范围内改用替代饲养系统之后，但在驱虫药可用之前进行的。此外，还研究了 2004 年农场和鸡群特征及管理对流行率的影响。结果表明，2008 年的总体流行率（38%；n=64/169）明显高于 2004 年（24%；n=44/186）（P=0.001）。在这两年中，笼养鸡群（包括有设施（丰富）的鸡笼）中的蛔虫感染均很少见（2.4%至 4.3%），而非笼养系统中的感染更为常见（2004 年为 16.7%至 48.6%，2008 年为 28.6%至 77.1%，取决于饲养系统）。在室内垫料饲养的鸡和自由放养/有机鸡之间，流行率没有显著差异。房屋或鸡舍单元入口处没有卫生屏障会增加感染的风险（P<0.001），这表明寄生虫卵是水平传播到农场的。鸡舍中使用的设备的年龄也会增加感染的风险；例如，与使用≥7 年的设备相比，设备使用 1 年的感染风险增加了 7.5 倍（95%置信区间=2.3 至 25）。本研究结果表明，改用替代饲养系统后，蛔虫感染可能会再次出现。随着欧盟成员国对传统笼养的禁令即将生效，蛔虫感染可能会变得更加重要，所有农场都应实施卫生屏障等有效的控制措施。
