Ehlers Julian, Ganzhorn Jörg U, Silaghi Cornelia, Krüger Andreas, Pothmann Daniela, Ratovonamana R Yedidya, Veit Alexandra, Keller Christian, Poppert Sven
Biozentrum Grindel, University of Hamburg, Hamburg, Germany; Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany.
Biozentrum Grindel, University of Hamburg, Hamburg, Germany.
Ticks Tick Borne Dis. 2016 Mar;7(2):378-83. doi: 10.1016/j.ttbdis.2015.12.011. Epub 2015 Dec 17.
Little is known about the role of endemic ticks as vectors for bacterial and protozoan pathogens for animals and humans in Madagascar and their interaction in anthropogenic habitats where humans, their livestock and native Malagasy species (vectors and hosts) come into more frequent contact than in natural forest ecosystems. The aims of the study were (1) to test whether habitat degradation is associated with increased infestation of tortoises by ticks and (2) to investigate whether ticks carried Babesia, Borrelia or Rickettsia species that might be pathogenic for humans and livestock. We studied hard ticks of two endemic Malagasy tortoises, Astrochelys radiata and Pyxis arachnoides in March and April 2013 in southwest Madagascar. Two tortoise habitats were compared, the National Park of Tsimanampetsotsa and the adjacent degraded pasture and agricultural land at the end of the wet season. Ticks were screened for protozoan and bacterial pathogens via PCR on DNA isolated from ticks using genus-specific primers. Only one out of 42 A. radiata collected from both habitats had ticks. The low prevalence did not allow further analyses of the effect of habitat degradation. Forty-two P. arachnoides were found in the anthropogenic habitat and 36 individuals in the national park. Tick infestation rates of P. arachnoides differed significantly between the two study sites. Tortoises inside the park had lower tick prevalence than outside (8 of 36 (22%) versus 32 of 42 individuals (76%)) and infected animals tended to have fewer ticks inside than outside the park. All ticks collected in both habitats were adults of the ixodid tick Amblyomma chabaudi, which is supposed to be a host-specific tick of P. arachnoides. Screening for Borrelia sp. and Babesia sp. was negative in all ticks. But all A. chabaudi ticks were infected with Rickettsia africae, known to cause spotted fever in humans. Thus, habitat degradation seems to be linked to higher infestation of tortoises with ticks with possible consequences for humans and their livestock.
关于马达加斯加地方蜱作为动物和人类细菌及原生动物病原体传播媒介的作用，以及在人类、家畜与马达加斯加本土物种（传播媒介和宿主）比在天然森林生态系统中接触更频繁的人为栖息地中它们之间的相互作用，人们了解甚少。本研究的目的是：（1）测试栖息地退化是否与蜱对乌龟的侵扰增加有关；（2）调查蜱是否携带可能对人类和家畜致病的巴贝斯虫属、疏螺旋体属或立克次氏体属物种。2013年3月和4月，我们在马达加斯加西南部研究了马达加斯加两种地方乌龟辐射陆龟和蛛网陆龟身上的硬蜱。比较了两种乌龟栖息地，即齐曼纳姆佩索察国家公园以及雨季末相邻的退化牧场和农田。通过聚合酶链反应（PCR），使用属特异性引物，从蜱中分离出的DNA对蜱进行原生动物和细菌病原体筛查。从两个栖息地收集的42只辐射陆龟中只有一只身上有蜱。这种低患病率使得无法进一步分析栖息地退化的影响。在人为栖息地发现了42只蛛网陆龟，在国家公园发现了36只。两个研究地点的蛛网陆龟蜱侵扰率有显著差异。公园内的乌龟蜱患病率低于公园外（36只中有8只（22%），而42只中有32只（76%）），且受感染动物身上的蜱在公园内比在公园外往往更少。在两个栖息地收集的所有蜱都是长角血蜱的成年个体，该蜱被认为是蛛网陆龟的宿主特异性蜱。所有蜱中疏螺旋体属和巴贝斯虫属的筛查均为阴性。但所有长角血蜱都感染了非洲立克次氏体，已知该病原体可导致人类患斑点热。因此，栖息地退化似乎与蜱对乌龟的更高侵扰有关，可能会对人类及其家畜产生影响。
