Department of Veterinary Medicine and Animal Productions, University of Naples Federico II, Via Federico Delpino n.1, Naples, 80137, Italy.
BMC Vet Res. 2024 May 8;20(1):183. doi: 10.1186/s12917-024-04037-4.
Pigs are susceptible to several ruminant pathogens, including Coxiella burnetti, Schmallenberg virus (SBV) and bovine viral diarrhea virus (BVDV). These pathogens have already been described in the pig population, although the dynamics of the infection and the impact on pig farms are currently unclear. The aim of this work was to evaluate the presence of these infections in the pig population of the Campania region, southern Italy, and to evaluate the risk factors associated with a greater risk of exposure.
A total of 414 serum samples belonging to 32 herds were tested for the presence of antibodies against SBV, Coxiella, and BVD using commercial multispecies ELISA kits. SBV (5.3%) was the most prevalent pathogen, followed by Coxiella (4.1%) and BVD (3%). The risk factors included in the study (age, sex, province, farming system, ruminant density and major ruminant species) had no influence on the probability of being exposed to BVD and Coxiella, except for the location, in fact more pigs seropositive to Coxiella were found in the province of Caserta. However, the univariate analysis highlighted the influence of age, location, and sex on exposure to SBV. The subsequent multivariate analysis statistically confirmed the importance of these factors. The presence of neutralizing antibodies for SBV and BVDV, or antibodies directed towards a specific phase of infection for Coxiella was further confirmed with virus-neutralization assays and phase-specific ELISAs in a large proportion of positive samples. The presence of high neutralizing antibody titers (especially for SBV) could indicate recent exposures. Twelve of the 17 positive samples tested positive for antibodies against Coxiella phase I or II antigens, indicating the presence of both acute and chronic infections (one animal tested positive for both phases antibodies).
Our study indicates a non-negligible exposure of pigs from southern Italy to the above pathogens. Further studies are necessary to fully understand the dynamics of these infections in pigs, the impact on productivity, and the public health consequences in the case of Coxiella.
猪易感染几种反刍动物病原体，包括柯克斯体、沙姆布鲁病毒（SBV）和牛病毒性腹泻病毒（BVDV）。这些病原体已在猪群中被描述，但感染的动态及其对养猪场的影响目前尚不清楚。本研究的目的是评估意大利南部坎帕尼亚地区猪群中这些感染的存在情况，并评估与更高暴露风险相关的风险因素。
使用商业多物种 ELISA 试剂盒，对 32 个畜群的 414 份血清样本进行了针对 SBV、柯克斯体和 BVD 的抗体检测。结果表明，SBV（5.3%）是最普遍的病原体，其次是柯克斯体（4.1%）和 BVD（3%）。研究中纳入的风险因素（年龄、性别、省份、养殖系统、反刍动物密度和主要反刍动物种类）对 BVD 和柯克斯体的暴露概率没有影响，但地理位置除外，实际上，在卡塞塔省发现了更多的柯克斯体血清阳性猪。然而，单因素分析突出了年龄、位置和性别的影响。随后的多因素分析统计证实了这些因素的重要性。在大量阳性样本中，通过病毒中和试验和阶段特异性 ELISA 进一步证实了 SBV 和 BVDV 的中和抗体的存在，或针对柯克斯体感染特定阶段的抗体的存在。高中和抗体滴度（特别是 SBV）的存在可能表明最近有暴露。在 17 个阳性样本中，有 12 个样本对柯克斯体 I 期或 II 期抗原的抗体呈阳性，表明同时存在急性和慢性感染（一只动物对两种抗体均呈阳性）。
本研究表明，意大利南部的猪群存在不可忽视的上述病原体暴露。需要进一步研究以充分了解这些感染在猪群中的动态、对生产力的影响以及在柯克斯体情况下对公共卫生的影响。
