Q Fever Dairy Herd Status Determination Based on Serological and Molecular Analysis of Bulk Tank Milk
Q Fever Dairy Herd Status Determination Based on Serological and Molecular Analysis of Bulk Tank Milk
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DOI：
10.1111/tbed.12275
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发表时间：
2016-04-01
影响因子：
4.3
通讯作者：
da Silva, G. J.
中科院分区：
文献类型：
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作者：
Anastacio, S.;Carolino, N.;da Silva, G. J.
反刍动物被认为是伯氏科希氏菌的主要宿主。欧洲食品安全局强调，许多欧洲国家缺乏对Q热流行情况的了解。在葡萄牙中部随机选择的奶牛群（n = 109）中进行了一项横断面研究，以筛查伯氏梭菌感染并将其与畜群因素联系起来。采用酶联免疫吸附法（ELISA）和聚合酶链反应（PCR）检测了45头牛和64头小反刍动物的散装罐乳（BTM）。估计Q热的血清表观患病率为45.9% (95% CI: 36.3-55.7)，小反刍动物（51.6;95% CI: 39.6-63.4）高于牛（37.8;95% CI: 25.1-52.4）。11.9% （95% CI: 7.1 ~ 19.4）的BTM中检测到伯氏梭菌的脱落，其中牛（20%,95% CI: 10.9 ~ 33.8）高于羊和混合牛群（6.3%,95% CI: 2.5 ~ 15）。在85%的pcr阳性BTM中观察到高细菌载量（= 3 9 10 3个细菌/ml）。细菌载量与ELISA阳性样品呈显著相关（P < 0.001）。抗体阳性与猪群规模增加（P < 0.01）和流产发生率极显著相关（P < 0.05），伯氏梭菌脱落与猪不孕症报告极显著相关（P < 0.05）。结果表明，血清学和分子方法相结合是筛查Q热和明确畜群感染状况的有效工具。伯氏杆菌通过牛奶的脱落是重要的，特别是在奶牛中，因此，牛奶作为乳业工人感染的潜在来源的作用不应被忽视。据我们所知，这是首次报道葡萄牙奶牛中伯纳蒂胞杆菌感染的研究，表明Q热在奶牛群中很重要，导致经济损失并对公共卫生构成风险，这突出了实施控制措施的必要性。
Ruminants are recognized as the main reservoirs of Coxiella burnetii. EFSA highlighted the lack of knowledge about Q fever prevalence in many European countries. A cross-sectional study was carried out in randomly selected dairy herds (n = 109) from central Portugal to screen for C. burnetii infection and to correlate it with herd factors. Bulk tank milk (BTM) samples from cattle (n = 45) and small ruminant (n = 64) herds were tested by ELISA and PCR. The apparent seroprevalence of Q fever was estimated in 45.9% (95% CI: 36.3-55.7) being higher in small ruminants (51.6; 95% CI: 39.6-63.4) than in cattle (37.8; 95% CI: 25.1-52.4). The shedding of C. burnetii in BTM was detected in 11.9% (95% CI: 7.1-19.4) of BTM, and it was higher in cattle (20%; 95% CI: 10.9-33.8) than in sheep and mixed herds (6.3%; 95% CI: 2.5-15). A high bacterial load (= 3 9 10 3 bacteria/ml) was observed in 85% of PCR-positive BTM. A significant correlation was found between the bacterial load and positive samples on ELISA (P < 0.001). Antibody positivity was significantly associated with the increased herd size (P < 0.01) and the occurrence of abortion (P < 0.05), whereas the shedding of C. burnetii was significantly associated with the report of infertility (P < 0.05). The results highlight that serological and molecular methods in combination are a useful tool to screen for Q fever and to clarify the herd infection status. The shedding of C. burnetii through milk is important, especially in dairy cattle, and thus, the role of milk as a potential source of infection among dairy workers should not be neglected. To our knowledge, this is the first study reporting C. burnetii infection in dairy livestock in Portugal showing that Q fever is significant in dairy herds, leading to economic losses and being a risk for public health, which highlights the need of implementation of control measures.