Abarca Katia, López Javier, Acosta-Jamett Gerardo, Martínez-Valdebenito Constanza
Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile.
Vector Borne Zoonotic Dis. 2013 Aug;13(8):607-9. doi: 10.1089/vbz.2012.1201. Epub 2013 May 9.
Rickettsia felis is an emerging agent considered a human threat; although its natural reservoir and agent of transmission is the cat flea, it has been also found in other vectors. R. felis has been identified in Chile in cat fleas and in one specimen of Rhipicephalus sanguineus collected in the Metropolitan Region. The objective of this study was to detect the presence of Rickettsia spp. in R. sanguineus from dogs of two different and distant geographical areas in Chile.
We performed a domiciliary sampling in urban and rural localities of two distant areas of the country-the Metropolitan Region in the center and the northern city of Arica. A total of 460 households were visited; one dog per household was included in the study and ectoparasites were collected from them.
R. sanguineus was found in 50% of the 460 dogs. R. felis was identified by amplification and sequencing of gltA, ompA, and ompB genes in R. sanguineus from both regions, with predominance in Arica.
The presence of R. felis in R. sanguineus from two distant regions of Chile suggests that this rickettsial agent is well established in the country. Considering that no human spotted fever group infections have been recognized in the country, the results should alert clinicians about such possible cases. The role of R. sanguineus in the epidemiology and transmission of R. felis should be further investigated.
猫立克次体是一种新出现的病原体，被认为对人类构成威胁；尽管其天然宿主和传播媒介是猫蚤，但也在其他媒介中被发现。在智利，已在猫蚤以及在首都大区采集的一只血红扇头蜱标本中鉴定出猫立克次体。本研究的目的是检测智利两个不同且距离遥远的地理区域的犬只身上的血红扇头蜱中是否存在立克次体属。
我们在该国两个遥远地区——中部的首都大区和北部城市阿里卡的城市和农村地区进行了家庭抽样。共走访了460户家庭；每户一只犬只纳入研究，并从它们身上采集体外寄生虫。
在460只犬中的50%发现了血红扇头蜱。通过对来自两个地区的血红扇头蜱的gltA、ompA和ompB基因进行扩增和测序，鉴定出了猫立克次体，在阿里卡更为常见。
在智利两个遥远地区的血红扇头蜱中存在猫立克次体，这表明这种立克次体病原体在该国已广泛存在。鉴于该国尚未发现人类斑点热群感染病例，这些结果应提醒临床医生注意此类可能的病例。血红扇头蜱在猫立克次体的流行病学和传播中的作用应进一步研究。
