Sciensano, Bacterial zoonoses unit, Veterinary bacteriology, Brussels, Belgium; Sciensano, Unit of exotic viruses and vector-borne diseases, Brussels, Belgium.
Sciensano, Department of epidemiology and public health, service of veterinary epidemiology, Brussels, Belgium.
Ticks Tick Borne Dis. 2023 Jul;14(4):102146. doi: 10.1016/j.ttbdis.2023.102146. Epub 2023 Apr 10.
Anaplasmosis, borreliosis, rickettsiosis and babesiosis are tick-borne diseases of medical, veterinary and economic importance. In Belgium, little is known on the prevalence of these diseases in animals and previous screenings relate only to targeted geographic regions, clinical cases or a limited number of tested samples. We therefore performed the first nationwide seroprevalence study of Anaplasma spp., A. phagocytophilum, Borrelia spp., Rickettsia spp. and Babesia spp. in Belgian cattle. We also screened questing ticks for the aforementioned pathogens.
ELISAs and IFATs were performed on a representative sample set of cattle sera stratified proportionally to the number of cattle herds per province. Questing ticks were collected in areas where the highest prevalence for the forenamed pathogens in cattle serum were observed. Ticks were analyzed by quantitative PCR for A. phagocytophilum (n = 783), B. burgdorferi sensu lato (n = 783) and Rickettsia spp. (n = 715) and by PCR for Babesia spp. (n = 358).
The ELISA screening for antibodies to Anaplasma spp. and Borrelia spp. in cattle sera showed an overall seroprevalence of 15.6% (53/339) and 12.9% (52/402), respectively. The IFAT screening for antibodies against A. phagocytophilum, Rickettsia spp. and Babesia spp. resulted in an overall seroprevalence of 34.2% (116/339), 31.2% (99/317) and 3.4% (14/412), respectively. At the provincial level, the provinces of Liege and Walloon Brabant harboured the highest seroprevalence of Anaplasma spp. (44.4% and 42.7% respectively) and A. phagocytophilum (55.6% and 71.4%). East Flanders and Luxembourg exhibited the highest seroprevalence of Borrelia spp. (32.4%) and Rickettsia spp. (54.8%) respectively. The province of Antwerp showed the highest seroprevalence of Babesia spp. (11%). The screening of field-collected ticks resulted in a prevalence of 13.8% for B. burgdorferi s.l., with B. afzelii and B. garinii being the most common genospecies (65.7% and 17.1%, respectively). Rickettsia spp. was detected in 7.1% of the tested ticks and the only identified species was R. helvetica. A low prevalence was found for A. phagocytophilum (0.5%) and no Babesia positive tick was detected.
The seroprevalence data in cattle indicate hot spots for tick-borne pathogens in specific provinces and highlights the importance of veterinary surveillance in anticipating the emergence of diseases among humans. The detection of all pathogens, with the exception of Babesia spp. in questing ticks, underlines the need of raising awareness among public and professionals on other tick-borne diseases along with lyme borreliosis.
嗜吞噬细胞无形体病、莱姆病、立克次氏体病和巴贝斯虫病是具有医学、兽医和经济重要性的蜱传疾病。在比利时，人们对这些疾病在动物中的流行情况知之甚少，以前的筛查仅涉及特定的地理区域、临床病例或有限数量的检测样本。因此，我们在比利时牛群中进行了首次全国范围内的无形体属、嗜吞噬细胞无形体、螺旋体属、立克次氏体属和巴贝斯虫属的血清流行率研究。我们还对采集的寄生蜱进行了上述病原体的筛查。
使用 ELISA 和 IFAT 对按省份牛群数量比例分层的代表性牛血清样本进行检测。在牛血清中上述病原体流行率最高的地区采集寄生蜱。对 783 份寄生蜱进行嗜吞噬细胞无形体定量 PCR 分析、783 份 B. burgdorferi sensu lato 进行定量 PCR 分析和 715 份立克次氏体属进行 PCR 分析，对 358 份寄生蜱进行巴贝斯虫属 PCR 分析。
牛血清中针对无形体属和螺旋体属的 ELISA 筛查显示，总抗体血清阳性率分别为 15.6%（53/339）和 12.9%（52/402）。针对嗜吞噬细胞无形体、立克次氏体属和巴贝斯虫属的 IFAT 筛查显示，总抗体血清阳性率分别为 34.2%（116/339）、31.2%（99/317）和 3.4%（14/412）。在省级水平上，列日省和瓦隆布拉班特省的无形体属血清阳性率最高（分别为 44.4%和 42.7%），嗜吞噬细胞无形体血清阳性率最高（分别为 55.6%和 71.4%）。东佛兰德省和卢森堡省的螺旋体属血清阳性率最高（分别为 32.4%和 31.2%），立克次氏体属血清阳性率最高（分别为 54.8%和 48.8%）。安特卫普省的巴贝斯虫属血清阳性率最高（11%）。野外采集的寄生蜱筛查结果显示，B. burgdorferi s.l.的流行率为 13.8%，其中 B. afzelii 和 B. garinii 是最常见的种（分别为 65.7%和 17.1%）。在 7.1%的检测寄生蜱中检测到立克次氏体属，唯一鉴定出的物种是 R. helvetica。嗜吞噬细胞无形体的流行率较低（0.5%），未检测到巴贝斯虫阳性寄生蜱。
牛血清的血清流行率数据表明，特定省份存在蜱传病原体的热点，突出了兽医监测在预测人类疾病出现方面的重要性。在寄生蜱中检测到所有病原体，除了巴贝斯虫属，这突出了在莱姆病之外提高公众和专业人士对其他蜱传疾病认识的必要性。
