蜱传病原体的持续扩张：丹麦的蜱传脑炎病毒复合体和嗜吞噬细胞无形体。

Continued expansion of tick-borne pathogens: Tick-borne encephalitis virus complex and Anaplasma phagocytophilum in Denmark.

机构信息

Clinical Centre for Emerging and Vector-borne Infections, Odense University Hospital, Sdr. Boulevard 29, DK-5000, Odense C, Denmark; Research Unit of Clinical Microbiology, University of Southern Denmark, J.B. Winsløvsvej 21.2, DK-5000, Odense C, Denmark.

Danish Hunters Association, Molsvej 34, DK-8410, Rønde, Denmark.

出版信息

Ticks Tick Borne Dis. 2019 Jan;10(1):115-123. doi: 10.1016/j.ttbdis.2018.09.007. Epub 2018 Sep 17.

DOI:10.1016/j.ttbdis.2018.09.007

PMID:30245088

Abstract

Tick-borne encephalitis virus (TBEV) is a tick-transmitted flavivirus within the tick-borne encephalitis (TBE) complex. The TBE complex is represented by both TBEV and louping ill virus (LIV) in Denmark. Anaplasma phagocytophilum is also transmitted by ticks and is believed to play an essential role in facilitating and aggravating LIV infection in sheep. This study aimed to describe the distribution of TBE complex viruses in Denmark, to establish the possible emergence of new foci and their association with the distribution of A. phagocytophilum. We performed a nationwide seroprevalence study of TBE complex viruses using roe deer (Capreolus capreolus) as sentinels and determined the prevalence of A. phagocytophilum in roe deer. Danish hunters obtained blood samples from roe deer during the hunting season of 2013-14. The samples were examined for TBEV-specific antibodies by virus neutralization tests (NT). A. phagocytophilum infection was assessed by specific real-time-PCR. The overall seroprevalence of the TBE complex viruses in roe deer was 6.9% (51/736). The positive samples were primarily obtained from a known TBE endemic foci and risk areas identified in previous sentinel studies. However, new TBE complex risk areas were also identified. The overall prevalence of A. phagocytophilum was 94.0% (173 PCR-positive of 184 roe deer), which is twice the rate observed ten years ago. These results point to an expansion of these tick-borne diseases geographically and within reservoir populations and, therefore, rationalize the use of sentinel models to monitor changes in transmission of tick-borne diseases and development of new risk areas. We found no association between TBE complex-positive roe deer and the prevalence of A. phagocytophilum, as almost all roe deer were infected. Based on our findings we encourage health care providers to be attentive to tick-borne illnesses such as TBE when treating patients with compatible symptoms.

摘要

蜱传脑炎病毒（TBEV）是一种蜱传黄病毒，属于蜱传脑炎（TBE）病毒复合体。在丹麦，TBE 病毒复合体由 TBEV 和卢平伊病毒（LIV）组成。嗜吞噬细胞无形体也是通过蜱传播的，被认为在促进和加重绵羊的 LIV 感染方面发挥着重要作用。本研究旨在描述丹麦 TBE 病毒复合体的分布情况，确定新疫区的出现及其与嗜吞噬细胞无形体分布的关系。我们使用狍（Capreolus capreolus）作为哨位动物进行了全国性的 TBE 病毒复合体血清流行率研究，并确定了狍体内嗜吞噬细胞无形体的流行率。丹麦猎人在 2013-14 年的狩猎季节从狍身上采集血液样本。通过病毒中和试验（NT）检测 TBEV 特异性抗体，检测样本中是否存在 TBEV。通过特定的实时 PCR 评估嗜吞噬细胞无形体感染情况。狍体内 TBE 病毒复合体的总血清流行率为 6.9%（736 份样本中有 51 份阳性）。阳性样本主要来自已知的 TBE 地方性流行区和以前哨位研究确定的风险区。然而，也发现了新的 TBE 复合风险区。嗜吞噬细胞无形体的总流行率为 94.0%（184 只狍中有 173 只 PCR 阳性），是十年前的两倍。这些结果表明，这些蜱传疾病在地理范围和宿主种群中都有所扩大，因此，利用哨位模型来监测蜱传疾病传播的变化和新风险区的发展是合理的。我们没有发现 TBE 复合体阳性狍与嗜吞噬细胞无形体流行率之间存在关联，因为几乎所有的狍都被感染了。基于我们的研究结果，我们鼓励医疗保健提供者在治疗有类似症状的患者时，注意 TBE 等蜱传疾病。