Abramowicz K F, Wekesa J W, Nwadike C N, Zambrano M L, Karpathy S E, Cecil D, Burns J, Hu R, Eremeeva M E
Rickettsial Zoonoses Branch, Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Atlanta, GA, U.S.A.
Med Vet Entomol. 2012 Dec;26(4):458-62. doi: 10.1111/j.1365-2915.2012.01017.x. Epub 2012 Jun 20.
Los Angeles and Orange Counties are known endemic areas for murine typhus in California; however, no recent reports of flea-borne rickettsioses are known from adjacent San Bernardino County. Sixty-five opossums (Didelphis virginiana) were trapped in the suburban residential and industrial zones of the southwestern part of San Bernardino County in 2007. Sixty out of 65 opossums were infested with fleas, primarily cat fleas, Ctenocephalides felis (Bouché, 1835). The flea minimum infection rate with Rickettsia felis was 13.3% in pooled samples and the prevalence was 23.7% in single fleas, with two gltA genotypes detected. In spite of historic records of murine typhus in this area, no evidence for circulation of R. typhi in fleas was found during the present study. Factors contributing to the absence of R. typhi in these cat fleas in contrast to its presence in cat fleas from Orange and Los Angeles Counties are unknown and need to be investigated further in San Bernardino County.
洛杉矶县和奥兰治县是加利福尼亚州已知的鼠型斑疹伤寒流行地区；然而，相邻的圣贝纳迪诺县近期尚无跳蚤传播立克次体病的报告。2007年，在圣贝纳迪诺县西南部的郊区住宅区和工业区捕获了65只负鼠（弗吉尼亚负鼠）。65只负鼠中有60只感染了跳蚤，主要是猫蚤，即猫栉首蚤（Bouché，1835年）。合并样本中猫蚤感染费氏立克次体的最低感染率为13.3%，单只跳蚤的感染率为23.7%，检测到两种gltA基因型。尽管该地区有鼠型斑疹伤寒的历史记录，但在本研究中未发现跳蚤中有伤寒立克次体传播的证据。与奥兰治县和洛杉矶县的猫蚤中存在伤寒立克次体相比，导致这些猫蚤中不存在伤寒立克次体的因素尚不清楚，需要在圣贝纳迪诺县进一步调查。
