Center of Tropical Medicine and Travel Medicine, Department of Infectious Diseases, Division of Internal Medicine, Amsterdam University Medical Center, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
Leptospirosis Reference Center, Department of Medical Microbiology, Amsterdam University Medical Center, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
Clin Infect Dis. 2021 Apr 8;72(7):1171-1178. doi: 10.1093/cid/ciaa091.
Rickettsial disease (RD) is a prevalent and underestimated cause of febrile illness worldwide, especially in the absence of an inoculation eschar. We attempted to quantify this underestimation at our clinic, by investigating past cases of febrile illness in travelers who had tested negative for leptospirosis, a disease that can initially present similarly to non-eschar RD, and which we routinely consider when other important causes of unspecified febrile illness have tested negative.
We performed a retrospective analysis in febrile returned travelers from Asia, Africa, or the Americas between 2010 and 2017, who had tested negative for leptospirosis. Serologic immunofluorescence assays were performed for Orientia tsutsugamushi (scrub typhus), typhus group, and spotted fever group RD. We performed a medical records review of all patients who tested positive. In case of a fitting medical history, cases were deemed either confirmed (based on convalescent serology) or suspected (based on single serology).
Among 97 patients, convalescent serology was available in 16 (16.5%) patients, and a single serology in 81 (83.5%) patients. RD was the likely diagnosis in 8 of 16 (50.0%) patients with convalescent serology, and in 8 of 81 (9.9%) with single serology. Of the 16 confirmed/suspected cases, 11 (69%) had been missed and 7 (44%) had not received adequate empiric antibiotic therapy.
This study shows that non-eschar RD is an important and poorly recognized cause of illness in travelers, even in a specialized travel clinic. A lower threshold to test and treat for RD is warranted in returning travelers with febrile illness.
立克次体病（RD）是一种普遍存在且被低估的发热性疾病病因，在全球范围内都有发生，尤其是在没有接种焦痂的情况下。我们试图通过调查过去在亚洲、非洲或美洲旅行后出现发热但检测莱姆病（一种最初表现与无焦痂 RD 相似的疾病，在检测到其他不明原因发热的重要病因呈阴性时，我们通常会考虑这种疾病）呈阴性的旅行者的发热病例，来定量评估这种低估的程度。
我们对 2010 年至 2017 年间在亚洲、非洲或美洲旅行后出现发热且检测莱姆病呈阴性的旅行者进行了回顾性分析。对恙虫病东方体（丛林斑疹伤寒）、斑疹伤寒组和斑点热组 RD 进行血清免疫荧光检测。对所有检测呈阳性的患者进行病历回顾。对于符合病史的病例，根据恢复期血清学将病例视为确诊（基于恢复期血清学）或疑似（基于单次血清学）。
在 97 例患者中，16 例（16.5%）患者有恢复期血清学检测结果，81 例（83.5%）患者仅有单次血清学检测结果。在有恢复期血清学检测结果的 16 例患者中，8 例（50.0%）患者的 RD 可能是诊断结果，在仅有单次血清学检测结果的 81 例患者中，8 例（9.9%）患者的 RD 可能是诊断结果。在 16 例确诊/疑似病例中，有 11 例（69%）被漏诊，7 例（44%）未接受足够的经验性抗生素治疗。
本研究表明，无焦痂 RD 是旅行者发热的一个重要且认识不足的病因，即使在专门的旅行诊所也是如此。对于出现发热的旅行者，应降低检测和治疗 RD 的门槛。
