APPARENT REINFECTION OF ENZOOTIC-PNEUMONIA-FREE PIG HERDS - SEARCH FOR POSSIBLE CAUSES
APPARENT REINFECTION OF ENZOOTIC-PNEUMONIA-FREE PIG HERDS - SEARCH FOR POSSIBLE CAUSES
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DOI：
10.1136/vr.116.26.690
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发表时间：
1985-01-01
影响因子：
2.2
通讯作者：
GOODWIN, RFW
中科院分区：
文献类型：
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作者：
GOODWIN, RFW
在猪健康控制协会管理的无地方性肺炎猪群控制方案中，对55个出现地方性肺炎的猪群进行了详细研究，但没有给出简单的解释。将这些猪群与1984年中期未患地方性肺炎的57头猪群进行比较。防止人类和污染物传播感染风险的高标准预防措施似乎没有带来明显的好处。这一观察结果与体外研究一致，该研究表明，尽管肺炎支原体可以在有利的液体培养基中存活很长时间，但一旦培养物变干，就无法从布等材料中恢复。在野外条件下，这种微生物可能在48小时内停止感染。然而，这种生物在较低温度的雨水中存活得特别好，通过潮湿的冷空气传播似乎是可能的。秋季和冬季开始出现故障的趋势，特别是在高度安全的单位，一些农民将更冷的多雾条件与感染的到来联系起来。其中一群猪可能是被一头进口猪感染的，而其他15群猪与外国猪非常接近，比如在屠宰场运输过程中，似乎是最可能的解释。其中一群被替换后，没有注意到这种危险，很快又崩溃了，而替换后幸存下来的这三类牧群都消除了这种风险。利用基于其他猪群邻近程度的风险指数，对39个剩余猪群中的37个与57个幸存猪群的数据进行了比较。（摘要删节250字）
In a control scheme for enzootic-pneumonia-free herds, run by the Pig Health Control Association, a detailed study was made of 55 herds that developed enzootic pneumonia without a simple explanation. These herds were compared with 57 herds that were still free from enzootic pneumonia in mid-1984. A high standard of precautions against the risk of infection being transferred by people and fomites seemed to confer no obvious benefit. This observation was in keeping with in vitro studies which showed that, although Mycoplasma hyopneumoniae could survive for a long time in favourable liquid medium, it could not be recovered from material such as cloth, once the culture had become dry. Under field conditions, the organism would probably cease to be infective within 48 hours. The organism survived particularly well in rain water at lower temperatures, however, and transmission via moist cold air seemed a possibility. There was a tendency for breakdowns to start in the autumn and winter, particularly in highly secure units, and several farmers associated colder misty conditions with the arrival of infection. One herd was probably infected by an imported boar and the very close proximity of foreign pigs, such as in slaughterhouse transport, seemed the most likely explanation in 15 other herds. One herd was replaced without this danger being attended to and it soon broke down again, whereas the three herds in this category that have survived after replacement all had this risk eliminated. Data was available on 37 of the 39 remaining herds to compare them with the 57 surviving herds, using a risk index based on the proximity of other pig units.(ABSTRACT TRUNCATED AT 250 WORDS)