Takken Willem, Verhulst Niels, Scholte Ernst-Jan, Jacobs Frans, Jongema Yde, van Lammeren Ron
Laboratory of Entomology, Wageningen University, P.O. Box 8031, 6700 EH Wageningen, The Netherlands.
Prev Vet Med. 2008 Oct 15;87(1-2):41-54. doi: 10.1016/j.prevetmed.2008.06.015. Epub 2008 Jul 18.
The Netherlands has enjoyed a relatively free state of vector-borne diseases of economic importance for more than one century. Emerging infectious diseases may change this situation, threatening the health of humans, domestic livestock and wildlife. In order to be prepared for the potential outbreak of vector-borne diseases, a study was undertaken to investigate the distribution and seasonal dynamics of candidate vectors of infectious diseases with emphasis on bluetongue vectors (Culicoides spp.). The study focused primarily on the relationship between characteristic ecosystems suitable for bluetongue vectors and climate, as well as on the phenology and population dynamics of these vectors. Twelve locations were selected, distributed over four distinct habitats: a wetland area, three riverine systems, four peat land areas and four livestock farms. Culicoides populations were sampled continuously using CO(2)-baited counterflow traps from July 2005 until August 2006, with an interruption from November 2005 to March 2006. All vectors were identified to species level. Meteorological and environmental data were collected at each location. Culicoides species were found in all four different habitat types studied. Wetland areas and peat bogs were rich in Culicoides spp. The taxonomic groups Culicoides obsoletus (Meigen) and Culicoides pulicaris (Linnaeus) were strongly associated with farms. Eighty-eight percent of all Culicoides consisted of the taxon C. obsoletus/Culicoides scoticus. On the livestock farms, 3% of Culicoides existed of the alleged bluetongue vector Culicoides dewulfi Goetghebuer. Culicoides impunctatus Goetghebuer was strongly associated with wetland and peat bog. Many Culicoides species were found until late in the phenological season and their activity was strongly associated with climate throughout the year. High annual variations in population dynamics were observed within the same study areas, which were probably caused by annual variations in environmental conditions. The study demonstrates that candidate vectors of bluetongue virus are present in natural and livestock-farm habitats in the Netherlands, distributed widely across the country. Under favourable climatic conditions, following virus introduction, bluetongue can spread among livestock (cattle, sheep and goats), depending on the nature of the viral serotype. The question now arises whether the virus can survive the winter conditions in north-western Europe and whether measures can be taken that effectively halt further spread of the disease.
一个多世纪以来，荷兰相对没有受到具有经济重要性的媒介传播疾病的困扰。新发传染病可能会改变这种状况，对人类、家畜和野生动物的健康构成威胁。为了应对媒介传播疾病可能的爆发，开展了一项研究，以调查传染病候选媒介的分布和季节动态，重点是蓝舌病媒介（库蠓属）。该研究主要关注适合蓝舌病媒介生存的典型生态系统与气候之间的关系，以及这些媒介的物候和种群动态。研究选取了12个地点，分布在四种不同的栖息地：一个湿地、三条河流系统、四个泥炭地和四个畜牧场。从2005年7月至2006年8月，使用二氧化碳诱饵逆流诱捕器连续采集库蠓种群样本，2005年11月至2006年3月期间中断。所有媒介均鉴定到物种水平。在每个地点收集气象和环境数据。在所研究的四种不同栖息地类型中均发现了库蠓物种。湿地和泥炭沼泽中库蠓种类丰富。废弃库蠓（Meigen）和刺螫库蠓（Linnaeus）这两个分类群与农场密切相关。所有库蠓中88%为废弃库蠓/苏格兰库蠓分类单元。在畜牧场中，3%的库蠓为所谓的蓝舌病媒介德氏库蠓（Goetghebuer）。无斑库蠓（Goetghebuer）与湿地和泥炭沼泽密切相关。许多库蠓物种在物候季节后期仍能被发现，并且它们的活动全年都与气候密切相关。在同一研究区域内观察到种群动态存在很大的年度变化，这可能是由环境条件的年度变化引起的。该研究表明，荷兰的自然栖息地和畜牧场中存在蓝舌病病毒的候选媒介，且在全国广泛分布。在有利的气候条件下，病毒传入后，蓝舌病可能会在牲畜（牛、绵羊和山羊）中传播，这取决于病毒血清型的性质。现在的问题是，该病毒能否在欧洲西北部的冬季条件下存活，以及是否可以采取措施有效阻止疾病的进一步传播。
