Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan.
Department of Internal Medicine, Section of Infectious Disease, Far Eastern Memorial Hospital, Taipei, Taiwan.
PLoS Negl Trop Dis. 2021 Apr 19;15(4):e0009355. doi: 10.1371/journal.pntd.0009355. eCollection 2021 Apr.
Current knowledge on Rickettsia felis infection in humans is based on sporadic case reports. Here we conducted a retrospective seroepidemiological survey of R. felis infection among febrile patients visiting a medical center in Taipei.
METHODOLOGY/PRINCIPAL FINDINGS: A total of 122 patients with suspected rickettsioses presenting with fever of unknown origin (FUO) but tested negative for scrub typhus, murine typhus, or Q fever were retrospectively identified during 2009 to 2010. The archived serum samples were examined for the presence of antibodies against R. felis, Rickettsia japonica, and Rickettsia typhi using microimmunofluorescence (MIF) assay. Serological evidence of Rickettsia exposure was found in 23 (19%, 23/122) patients. Eight patients had antibodies reactive to R. felis, including four with current infection (a ≥4-fold increase in IgG titer between acute and convalescent sera). The clinical presentations of these four patients included fever, skin rash, lymphadenopathy, as well as more severe conditions such as pancytopenia, hepatomegaly, elevated liver enzymes/bilirubin, and life-threatening acute respiratory distress syndrome. One of the patients died after doxycycline was stopped after being tested negative for scrub typhus, Q fever, and murine typhus.
Rickettsia felis is a neglected flea-borne pathogen in Taiwan, and its infection can be life-threatening. Further prospective studies of the prevalence of R. felis among patients with FUO and compatible clinical manifestations are warranted.
目前关于猫立克次体感染人类的知识主要基于零星的病例报告。在这里，我们对台北一家医疗中心发热患者进行了猫立克次体感染的回顾性血清流行病学调查。
方法/主要发现：2009 年至 2010 年，共回顾性确定了 122 例因不明原因发热（FUO）但经恙虫病、鼠型斑疹伤寒或 Q 热检测呈阴性的疑似立克次体病患者。用微量免疫荧光（MIF）法检测这些存档血清样本中是否存在针对猫立克次体、日本立克次体和伤寒立克次体的抗体。在 23 例（19%，23/122）患者中发现了血清学证据表明存在立克次体暴露。8 例患者的抗体对猫立克次体有反应，其中 4 例有现症感染（急性和恢复期血清 IgG 滴度增加≥4 倍）。这 4 例患者的临床表现包括发热、皮疹、淋巴结病，以及更严重的情况，如全血细胞减少症、肝肿大、肝酶/胆红素升高和危及生命的急性呼吸窘迫综合征。1 例患者在被检测出恙虫病、Q 热和鼠型斑疹伤寒阴性后停止使用强力霉素治疗后死亡。
猫立克次体是台湾被忽视的跳蚤传播病原体，其感染可能危及生命。有必要进一步前瞻性研究 FUO 患者和具有相似临床表现患者中猫立克次体的流行情况。
