Wagemakers Alex, Jahfari Seta, de Wever Bob, Spanjaard Lodewijk, Starink Markus V, de Vries Henry J C, Sprong Hein, Hovius Joppe W
Center for Experimental and Molecular Medicine, Academic Medical Center, Meibergdreef 9, 1105AZ Amsterdam, The Netherlands.
Center for Infectious Disease Control, Institute for Public Health and Environment, Antonie van Leeuwenhoeklaan 9, 3721 MA Bilthoven, The Netherlands.
Ticks Tick Borne Dis. 2017 Mar;8(3):370-374. doi: 10.1016/j.ttbdis.2016.12.012. Epub 2016 Dec 30.
Ixodes ticks transmit Borrelia burgdorferi sensu lato (s.l.), the causative agent of Lyme borreliosis (LB). These tick species also transmit Borrelia miyamotoi, which was recently found to cause infections in humans. We were interested in the prevalence of B. miyamotoi infection in ticks and natural hosts in The Netherlands, and to what extent ticks are co-infected with B. burgdorferi. In addition, erythema migrans has been sporadically described in B. miyamotoi-infected patients, but these skin lesions might as well represent co-infections with B. burgdorferi s.l. We therefore investigated whether B. miyamotoi was present in LB-suspected skin lesions of patients referred to our tertiary Lyme disease clinic. 3360 questing Ixodes ricinus nymphs as well as spleen tissue of 74 rodents, 26 birds and 10 deer were tested by PCR for the presence of B. miyamotoi. Tick lysates were also tested for the presence of B. burgdorferi s.l. Next, we performed a PCR for B. miyamotoi in 31 biopsies from LB-suspected skin lesions in patients visiting our tertiary Lyme center. These biopsies had been initially tested for B. burgdorferi s.l. by PCR, and the skin lesions had been investigated by specialized dermatologists. Out of 3360 unfed (or questing) nymphs, 313 (9.3%) were infected with B. burgdorferi s.l., 70 (2.1%) were infected with B. miyamotoi, and 14 (0.4%) were co-infected with B. burgdorferi s.l. and B. miyamotoi. Co-infection of B. burgdorferi s.l. with B. miyamotoi occurred more often than expected from single infection prevalences (p=0.03). Both rodents (9%) and birds (8%) were found positive for B. miyamotoi by PCR, whereas the roe deer samples were negative. Out of 31 LB-suspected skin biopsies, 10 (32%) were positive for B. burgdorferi s.l. while none were positive for B. miyamotoi. The significant association of B. burgdorferi s.l. with B. miyamotoi in nymphs implies the existence of mutual reservoir hosts. Indeed, the presence of B. miyamotoi DNA indicates systemic infections in birds as well as rodents. However, their relative contributions to the enzootic cycle of B. miyamotoi requires further investigation. We could not retrospectively diagnose B. miyamotoi infection using biopsies of LB-suspected skin lesions, supporting the hypothesis that B. miyamotoi is not associated with LB-associated skin manifestations. However, this warrants further studies in larger sets of skin biopsies. A prospective study focused on acute febrile illness after a tick bite could provide insight into the incidence and clinical manifestations of B. miyamotoi infection in The Netherlands.
硬蜱传播莱姆病（LB）的病原体伯氏疏螺旋体狭义种（Borrelia burgdorferi sensu lato，s.l.）。这些蜱种还传播伯氏米亚罗蜱（Borrelia miyamotoi），该病原体最近被发现可导致人类感染。我们对荷兰蜱及自然宿主中伯氏米亚罗蜱感染的流行情况，以及蜱与伯氏疏螺旋体共同感染的程度感兴趣。此外，在感染伯氏米亚罗蜱的患者中曾偶有游走性红斑的描述，但这些皮肤病变也可能代表同时感染了伯氏疏螺旋体狭义种。因此，我们调查了转诊至我们三级莱姆病诊所的疑似莱姆病患者的皮肤病变中是否存在伯氏米亚罗蜱。通过聚合酶链反应（PCR）检测了3360只饥饿（或正在觅食）的蓖麻硬蜱若虫以及74只啮齿动物、26只鸟类和10只鹿的脾脏组织中伯氏米亚罗蜱的存在情况。蜱的裂解物也检测了伯氏疏螺旋体狭义种的存在情况。接下来，我们对到我们三级莱姆病中心就诊的疑似莱姆病患者的31份皮肤病变活检样本进行了伯氏米亚罗蜱的PCR检测。这些活检样本最初已通过PCR检测伯氏疏螺旋体狭义种，且皮肤病变已由专业皮肤科医生进行了检查。在3360只未进食（或正在觅食）的若虫中，313只（9.3%）感染了伯氏疏螺旋体狭义种，70只（2.1%）感染了伯氏米亚罗蜱，14只（0.4%）同时感染了伯氏疏螺旋体狭义种和伯氏米亚罗蜱。伯氏疏螺旋体狭义种与伯氏米亚罗蜱的共同感染比单一感染的预期发生率更常见（p = 0.03）。通过PCR检测发现啮齿动物（9%）和鸟类（8%）的伯氏米亚罗蜱呈阳性，而狍子样本为阴性。在31份疑似莱姆病的皮肤活检样本中，10份（32%）伯氏疏螺旋体狭义种呈阳性，而没有一份伯氏米亚罗蜱呈阳性。若虫中伯氏疏螺旋体狭义种与伯氏米亚罗蜱的显著关联意味着存在共同的储存宿主。事实上，伯氏米亚罗蜱DNA的存在表明鸟类和啮齿动物存在全身感染。然而，它们对伯氏米亚罗蜱动物疫源循环的相对贡献需要进一步研究。我们无法通过疑似莱姆病皮肤病变的活检样本进行回顾性诊断伯氏米亚罗蜱感染，这支持了伯氏米亚罗蜱与莱姆病相关皮肤表现无关的假设。然而，这需要在更大规模的皮肤活检样本中进行进一步研究。一项针对蜱叮咬后急性发热性疾病的前瞻性研究可以深入了解荷兰伯氏米亚罗蜱感染的发病率和临床表现。
