Schriefer M E, Sacci J B, Taylor J P, Higgins J A, Azad A F
Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore 21201.
J Med Entomol. 1994 Sep;31(5):681-5. doi: 10.1093/jmedent/31.5.681.
Studies using serologic and polymerase chain reaction-(PCR) facilitated analysis of field samples from southern Texas indicate the presence of Rickettsia typhi and ELB agent infected cat fleas, Ctenocephalides felis (Bouché), and the first observation of ELB infected vertebrates (opossums). The ELB agent is a recently described typhus-like rickettsia that is not distinguished from R. typhi or R. prowazekii by currently available serologic reagents. Restriction digests of PCR products from 399 fleas revealed an ELB agent infection rate of 3.8% and a R. typhi infection rate of 0.8%. Three of nine tested opossums (Didelphis virginiana) were shown to harbor ELB agent infections. No R. typhi infected rats, Rattus norvegicus, or rat-fleas, Xenopsylla cheopis Rothschild, were detected among surveyed samples. The persistence of this murine typhus disease focus appears to be better accounted for by the presence of infected cat fleas, opossums, and other non-rat hosts found in close association with human populations. Involvement of the ELB agent in the biology of murine typhus is suggested by its prevalence among suspected vectors and reservoir hosts.
利用血清学和聚合酶链反应（PCR）对得克萨斯州南部的野外样本进行分析的研究表明，存在感染鼠型斑疹伤寒立克次体和埃博拉病毒（ELB）的猫蚤（猫栉首蚤，Bouché），并且首次观察到感染ELB的脊椎动物（负鼠）。ELB病原体是一种最近被描述的类斑疹伤寒立克次体，目前可用的血清学试剂无法将其与鼠型斑疹伤寒立克次体或普氏立克次体区分开来。对399只跳蚤的PCR产物进行限制性酶切分析显示，ELB病原体感染率为3.8%，鼠型斑疹伤寒立克次体感染率为0.8%。在检测的9只负鼠（弗吉尼亚负鼠）中，有3只被证明感染了ELB病原体。在调查样本中未检测到感染鼠型斑疹伤寒立克次体的大鼠（褐家鼠）或鼠蚤（印鼠客蚤，Rothschild）。这种鼠型斑疹伤寒疾病疫源地的持续存在似乎可以更好地解释为存在与人类密切相关的感染猫蚤、负鼠和其他非鼠宿主。ELB病原体在疑似媒介和储存宿主中的高流行率表明其参与了鼠型斑疹伤寒的生物学过程。
