Invasive rabbits host immature Ixodes ticks at the urban-forest interface

Introduced wildlife may be important alternative hosts for generalist ticks that cause health issues for humans and companion animals in urban areas, but to date are rarely considered as part of the tick-host community compared to native wildlife. In Australia, European rabbits, Oryctolagus cuniculus, are a widespread and abundant invasive species common to a range of human-modified ecosystems. To understand the potential role of rabbits in the life cycle of Australian ticks, we investigated the seasonal abundance of all tick life stages (larva, nymph, and adult) on rabbits collected from pest control programs in two urban forest remnants in Sydney, Australia. We also recorded whether larvae, nymphs, and adults were attached to the head, body, or limbs of rabbits to reveal patterns of tick attachment. Of the 2426 Ixodes ticks collected from 42 rabbits, larvae were by far the most abundant life stage (2360), peaking in abundance in autumn, while small numbers of nymphs (62) and adults (4) were present in winter and summer respectively. Larvae were found all over the body, whereas adults and nymphs were predominantly attached to the head, suggesting that the mature life stages use the host landscape differently, or that adults or nymphs may be groomed off the body. The most abundant tick species, as determined by morphology and DNA sequencing, was Ixodes holocyclus, a generalist tick responsible for significant human and companion animal health concerns in Australia. Our findings highlight the importance of understanding the role of introduced wildlife in tick dynamics particularly in novel ecosystems where non-native hosts may be more abundant than native hosts.     

七种媒介硬蜱基因组随机扩增多态性DNA分析

目的　研究7种硬蜱的基因组随机扩增多态性DNA(RAPD)以及种间的遗传距离。　方法　用5条不同的多聚核苷酸单链引物对草原革蜱、森林革蜱、青海血蜱、台湾血蜱、刻点血蜱、龟形花蜱、卵形硬蜱7种硬蜱基因组DNA进行随机扩增,分析DNA图谱并计算 7种硬蜱间的遗传距离。　结果　 7种硬蜱基因组随机扩增产物均有各自独特的DNA条带,种间的平均遗传距离为071。　结论　RAPD技术可以区分这7种硬蜱。     

新疆博尔塔拉和伊犁地区蜱类区系考察

本文报道了1990年4月3日至5月9日在博尔塔拉自治州的博乐、温泉和伊犁地区的察布查尔、新源、巩留、特克斯和昭苏等7县15个点,在北纬42°30′～45°15′,东经79°55′～84°35′,之间蜱类区系的考察结果。在此期间共获蜱类2700余只,结合既往的标本和资料,共记述该地区已知蜱类7属23种的采集地点、宿主及与疾病的关系。其中全沟硬蜱、边缘革蜱、森林革蜱、草原革蜱和残缘璃眼蜱的数量占优势,分布亦较广。业已证实,全沟硬蜱是森林脑炎和莱姆病的重要传播媒介,从边缘革蜱和草原革蜱体内已分离到土拉伦斯菌和蜱媒斑点热的病原体。     

新疆东部地区蜱螨区系及医学意义

通过对新疆东部地区蜱类和医螨的广泛调查，目前已发现蜱７属１２种；革螨６科１３属２７种；恙螨４属５种。革螨中的长毛美绥螨Ａｍｅｒｏｓｅｉｕｓ ｌｏｎｇｉｓｅｔｏｓｕｓ Ｙｅ ｅｔ Ｍａ，１９９３系近期发表的新种，阴阳血厉螨Ｈａｅｍｏｌａｅｌａｐｓ ａｎｄｒｏｇｙｎｕｓ Ｂｒｅｇｅｔｏｖａ，１９５２是国内新纪录，宽胸真厉螨Ｅｕｌａｅｌａｐｓ ｗｉｄｅｓｔｅｒｎａｌｉｓ Ｐｉａｏ ｅｔ Ｍａ，１９８０是     

九省区蜱类区系初步调查

目的：了解我国蜱类区系分布情况。方法：采集动物体表寄生蜱类,分类鉴定、分析蜱类区系分布与宿主范围。结果：采集蜱类共3135头,分为9属28种,其中6种地区分布新纪录,2种待定种。结论：蜱类区系分布调查为进一步蜱媒疾病调查和防制提供了依据。     

Tick-borne Relapsing Fever and Borrelia hermsii, Los Angeles County, California, USA

The primary cause of tick-borne relapsing fever in western North America is Borrelia hermsii, a rodent-associated spirochete transmitted by the fast-feeding soft tick Ornithodoros hermsi. We describe a patient who had an illness consistent with relapsing fever after exposure in the mountains near Los Angeles, California, USA. The patient’s convalescent-phase serum was seropositive for B. hermsii but negative for several other vector-borne bacterial pathogens. Investigations at the exposure site showed the presence of O. hermsi ticks infected with B. hermsii and the presence of rodents that were seropositive for the spirochete. We determined that this tick-borne disease is endemic to the San Gabriel Mountains near the greater Los Angeles metropolitan area.     

New tools,new tick-borne diseases?

Tick-borne diseases (TBDs) are a major public health concern that has increased in the past three decades. Nevertheless, emerging or reemerging TBDs may be still misdiagnosed. Molecular biology techniques for the screening of ticks, use of “Omics” approaches and the incorporation of analytical methods such as mass spectrometry or nuclear magnetic resonance, to the study of ticks and their associated pathogens or potential pathogens are promising tools for a more accurate differential diagnosis of TBDs. However, this huge amount of data needs to be carefully interpreted before being incorporated to the routine of clinical practice. In the meantime, a clinical approach and high level of suspicion keep being essential for the diagnosis and proper handling of TBDs.