Department of Eco-Epidemiology of Parasitic Diseases, Institute of Developmental Biology and Biomedical Sciences, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096, Warsaw, Poland.
Department of Eco-Epidemiology of Parasitic Diseases, Institute of Developmental Biology and Biomedical Sciences, Faculty of Biology, University of Warsaw, Miecznikowa 1, 02-096, Warsaw, Poland.
Ticks Tick Borne Dis. 2021 Jan;12(1):101551. doi: 10.1016/j.ttbdis.2020.101551. Epub 2020 Sep 16.
The red fox (Vulpes vulpes) is known to be a reservoir host of various vector-borne protozoan parasites. Yet, the impact of these parasitic infections on the health status of the red fox is unknown. In this study, we compared the prevalence of haemoprotozoa in juvenile and adult foxes from four regions in Poland. The abundance of questing adult Dermacentor reticulatus ticks was shown to differ between regions and include a tick-endemic and non-endemic region, as well as two zones in which D. reticulatus recently expanded: an eastern and a western zone. Spleen and kidney enlargement indices were compared between infected, co-infected and non-infected foxes to evaluate pathogenic output of parasitic infections. Blood samples were collected from 383 necropsied red foxes and 25 live-trapped red fox cubs. The weights of spleens, kidneys and bodies were recorded for each necropsied individual. Blood and spleen DNA samples were screened by PCR to detect 18S rRNA and cox1 gene fragments of Babesia spp., and 18S rRNA of Hepatozoon spp. Prevalence of infection and mean organ weight indices were compared in relation to fox age and sex, origin (zone) and infection status. Hepatozoon canis (174/381; 45.7%) and Babesia vulpes (117/381; 30.7%) were the dominant pathogens infecting adult foxes. Babesia canis DNA was detected in 9 (2.4%) individuals. Two fox cubs from Western Poland were infected with B. vulpes (2/14; 14%), while H. canis infection (16/25; 59%) was detected in cubs from all three regions where trapping was carried out. Infection with B. vulpes was associated with significantly higher weights of spleens and kidneys. Spleen weight/ body weight and mean kidney weight/ body weight indices were shown as relevant in evaluating changes occurring during infection with B. vulpes. Babesia and Hepatozoon spp. infections differed in red foxes from D. reticulatus-endemic, non-endemic and newly inhabited areas. The prevalence of B. canis in foxes from four regions of Poland reflects the prevalence recorded in questing adult D. reticulatus collected in these areas. This finding suggests a contribution of red foxes to the establishment of new foci of B. canis-infected D. reticulatus ticks in areas recently invaded by this tick species. Spleen and kidney enlargement was identified in foxes infected with B. vulpes, particularly in individuals co-infected with B. vulpes and H. canis.
红狐（Vulpes vulpes）已知是多种媒介传播原生动物寄生虫的储存宿主。然而，这些寄生虫感染对红狐健康状况的影响尚不清楚。在这项研究中，我们比较了来自波兰四个地区的幼年和成年狐狸中血液原生动物的流行率。结果表明，成蜱（Dermacentor reticulatus）的丰度在地区之间存在差异，包括一个疫区和一个非疫区，以及两个 D. reticulatus 最近扩张的区域：东部和西部区域。通过比较感染、合并感染和未感染狐狸的脾脏和肾脏肿大指数，评估寄生虫感染的致病作用。从 383 只剖检的红狐和 25 只活捕的红狐幼崽中采集血液样本。记录每只剖检个体的脾脏、肾脏和身体重量。用 PCR 检测血液和脾脏 DNA 样本，以检测贝氏巴贝斯虫和肝孢虫的 18S rRNA 和 cox1 基因片段。根据狐狸年龄和性别、来源（区域）和感染状况，比较感染率和平均器官重量指数。感染 H. canis（174/381; 45.7%）和 B. vulpes（117/381; 30.7%）是成年狐狸的主要病原体。在 9 只（2.4%）个体中检测到 B. canis DNA。来自波兰西部的两只幼狐感染了 B. vulpes（2/14; 14%），而在所有三个进行诱捕的地区的幼狐中都检测到了 H. canis 感染（16/25; 59%）。B. vulpes 感染与脾脏和肾脏重量显著增加相关。脾脏重量/体重和平均肾脏重量/体重指数被证明是评估 B. vulpes 感染过程中发生的变化的相关指标。在来自 D. reticulatus 疫区、非疫区和新栖息地的狐狸中，巴贝斯虫和肝孢虫感染存在差异。在波兰四个地区的狐狸中，B. canis 的流行率反映了在这些地区采集的成蜱 D. reticulatus 中记录的流行率。这一发现表明，红狐在蜱种新近入侵的地区建立了新的 B. canis 感染 D. reticulatus 蜱的热点方面发挥了作用。在感染 B. vulpes 的狐狸中发现了脾脏和肾脏肿大，特别是在感染 B. vulpes 和 H. canis 的个体中。
