Department of Production Animal Clinical Sciences, Norwegian School of Veterinary Science Sandnes, Norway.
Front Cell Infect Microbiol. 2013 Jul 22;3:31. doi: 10.3389/fcimb.2013.00031. eCollection 2013.
The bacterium Anaplasma phagocytophilum has for decades been known to cause the disease tick-borne fever (TBF) in domestic ruminants in Ixodes ricinus-infested areas in northern Europe. In recent years, the bacterium has been found associated with Ixodes-tick species more or less worldwide on the northern hemisphere. A. phagocytophilum has a broad host range and may cause severe disease in several mammalian species, including humans. However, the clinical symptoms vary from subclinical to fatal conditions, and considerable underreporting of clinical incidents is suspected in both human and veterinary medicine. Several variants of A. phagocytophilum have been genetically characterized. Identification and stratification into phylogenetic subfamilies has been based on cell culturing, experimental infections, PCR, and sequencing techniques. However, few genome sequences have been completed so far, thus observations on biological, ecological, and pathological differences between genotypes of the bacterium, have yet to be elucidated by molecular and experimental infection studies. The natural transmission cycles of various A. phagocytophilum variants, the involvement of their respective hosts and vectors involved, in particular the zoonotic potential, have to be unraveled. A. phagocytophilum is able to persist between seasons of tick activity in several mammalian species and movement of hosts and infected ticks on migrating animals or birds may spread the bacterium. In the present review, we focus on the ecology and epidemiology of A. phagocytophilum, especially the role of wildlife in contribution to the spread and sustainability of the infection in domestic livestock and humans.
噬吞噬细胞无形体（Anaplasma phagocytophilum）几十年来一直被认为是导致欧洲北方莱姆病（tick-borne fever，TBF）的病原体，在该地区，硬蜱（Ixodes ricinus）泛滥，家畜易受感染。近年来，该病原体在北半球的硬蜱种类中或多或少在世界范围内被发现与蜱有关。噬吞噬细胞无形体（A. phagocytophilum）宿主范围广泛，可能导致包括人类在内的几种哺乳动物发生严重疾病。然而，临床症状从亚临床到致命情况不等，并且在人类和兽医医学中都怀疑存在相当数量的临床事件漏报。噬吞噬细胞无形体（A. phagocytophilum）已在遗传上进行了多种变体的特征鉴定。通过细胞培养、实验感染、PCR 和测序技术对其进行鉴定和分类为进化支亚科。然而，到目前为止，完成的基因组序列很少，因此，通过分子和实验感染研究阐明该细菌基因型之间的生物学、生态学和病理学差异仍有待观察。各种噬吞噬细胞无形体变体的自然传播周期，包括它们各自的宿主和相关的媒介参与，特别是人畜共患病的潜力，都需要加以阐明。噬吞噬细胞无形体（A. phagocytophilum）能够在几种哺乳动物的硬蜱活动季节之间持续存在，并且宿主和受感染的蜱的移动可能会在迁徙动物或鸟类上传播细菌。在本综述中，我们重点关注噬吞噬细胞无形体（A. phagocytophilum）的生态学和流行病学，特别是野生动物在传播和维持家畜和人类感染中的作用。
