Marier E A, Snow L C, Floyd T, McLaren I M, Bianchini J, Cook A J C, Davies R H
Epidemiology, Surveillance and Risk Group, Animal Health and Veterinary Laboratories Agency, Weybridge, New Haw, Addlestone, Surrey KT15 3NB, United Kingdom.
Epidemiology, Surveillance and Risk Group, Animal Health and Veterinary Laboratories Agency, Weybridge, New Haw, Addlestone, Surrey KT15 3NB, United Kingdom.
Prev Vet Med. 2014 Dec 1;117(3-4):542-53. doi: 10.1016/j.prevetmed.2014.09.004. Epub 2014 Sep 19.
All European Union (EU) Member States (MSs) were required to conduct a baseline survey from October 2006 to September 2007 to estimate the prevalence of Salmonella infection in finisher pigs at slaughter. In the United Kingdom (UK), samples for microbiological culture were collected from the ileo-caecal lymph nodes, from carcass swabs and from caecal contents. Meat juice samples were also collected for testing in an enzyme-linked immunosorbent assay (MJE) to detect a serological response. Salmonella was isolated from 22% (CI95% 19-25%) of ileo-caecal lymph nodes, 15% (CI95% 12-18%) of carcass swabs and 22% (CI95% 19-26%) of caecal contents. A quarter (25%, CI95% 22-29%) of MJE samples were positive for Salmonella antibodies (cut-off, S/P≥0.25). The most frequently identified serovars were Salmonella typhimurium (57%) and Salmonella derby (26%). The results were used to investigate some factors associated with Salmonella infection in slaughter pigs. The weight of the carcass was significant, with a lower probability of obtaining a positive meat juice result from pigs with a weight greater than 75 kg (p=0.03). The weight of the lymph node sample was significantly associated with Salmonella status, with a heavier sample of lymph nodes being more likely to be positive (OR=2.16 CI95% 1.07-4.39). 'Carcass weight' in two of the classes - 75-79 kg and 80-84 kg - (OR=0.44 CI95% 0.28-0.70; OR=0.64 CI95% 0.49-0.85) and 'fewer-than-1500-pigs' scheduled for slaughter on the day of sampling' (OR=0.41 CI95% 0.24-0.71) were also associated with a reduced risk of isolating Salmonella from lymph node. The model for carcass swabs showed a positive association with 'time-elapsed-since-the-start-of-the-line' indicating a higher risk of contamination as the day progressed (p<0.01). This model also showed positive association between isolation of Salmonella from a carcass swab and the occurrence of Salmonella in caecal contents from the same pig (OR=2.22 CI95% 1.38-3.59) and a negative association with time in singeing units (OR=0.88 CI95% 0.79-0.98).
所有欧盟成员国都被要求在2006年10月至2007年9月期间进行一次基线调查，以估计屠宰时育肥猪沙门氏菌感染的流行率。在英国，微生物培养样本从回盲部淋巴结、胴体拭子和盲肠内容物中采集。还采集了肉汁样本，用于酶联免疫吸附测定（MJE）检测，以检测血清学反应。从22%（95%置信区间19 - 25%）的回盲部淋巴结、15%（95%置信区间12 - 18%）的胴体拭子和22%（95%置信区间19 - 26%）的盲肠内容物中分离出沙门氏菌。四分之一（25%，95%置信区间22 - 29%）的MJE样本沙门氏菌抗体呈阳性（临界值，S/P≥0.25）。最常鉴定出的血清型是鼠伤寒沙门氏菌（57%）和德比沙门氏菌（26%）。这些结果被用于调查与屠宰猪沙门氏菌感染相关的一些因素。胴体重量具有显著意义，体重超过75千克的猪获得阳性肉汁结果的概率较低（p = 0.03）。淋巴结样本的重量与沙门氏菌感染状况显著相关，淋巴结样本较重的更有可能呈阳性（比值比 = 2.16，95%置信区间1.07 - 4.39）。两个体重类别——75 - 79千克和80 - 84千克——（比值比 = 0.44，95%置信区间0.28 - 0.70；比值比 = 0.64，95%置信区间0.49 - 0.85）以及“采样当天计划屠宰的猪少于1500头”（比值比 = 0.41，95%置信区间0.24 - 0.71）也与从淋巴结中分离出沙门氏菌的风险降低有关。胴体拭子模型显示与“生产线开始后的时间”呈正相关，表明随着一天时间的推移污染风险更高（p < 0.01）。该模型还显示从胴体拭子中分离出沙门氏菌与同一头猪盲肠内容物中沙门氏菌的存在之间呈正相关（比值比 = 2.22，95%置信区间1.38 - 3.59），与燎毛单元中的时间呈负相关（比值比 = 0.88，95%置信区间0.79 - 0.98）。
