Typhus group rickettsioses (TGRs) are vector-borne diseases that include murine typhus (Rickettsia typhi) and epidemic typhus (R. prowazekii). Twentieth-century public health interventions led to dramatic decreases in incidence; little is known about the contemporary TGR prevalence because neither disease is nationally notifiable. We summarized administrative claims data in a commercially insured population to examine trends in TGR medical encounters. We analysed data from 2003 to 2016 IBM® MarketScan® Commercial Databases to identify persons with inpatient or outpatient visits with an International Classification of Diseases, Ninth or Tenth Revision, Clinical Modification TGR-specific code. We summarized epidemiologic characteristics associated with incident diagnosis. We identified 1,799 patients diagnosed with a TGR. Patients resided in 46 states, and most were female (n = 1,019/1,799; 56.6%); the median age was 42 years (range: 0-64 years). Epidemic typhus (n = 931/1,799; 51.8%) was the most common TGRs, followed by murine typhus (n = 722/1,799; 40.1%). The majority of TGR patients were diagnosed in an outpatient setting (n = 1,725/1,799; 95.9%); among hospitalized patients, the majority received a murine typhus diagnosis (n = 67/74; 90.5%). TGRs are rarely diagnosed diseases. More patients were diagnosed with epidemic than murine typhus, even though R. prowazekii transmission requires body louse or flying squirrel exposure. Patients from all geographic regions were diagnosed with murine and epidemic typhus, despite historically recognized ranges for these diseases. The epidemiologic misalignment of insurance claims data versus historic TGRs data highlights the challenges of finding appropriate alternative data sources to serve as a proxy when national surveillance data do not exist.

中文翻译：

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美国大型保险理赔数据库中斑疹伤寒群立克次体病的临床诊断趋势。

斑疹伤寒群立克次体病 (TGRs) 是媒介传播的疾病，包括鼠斑疹伤寒 (Rickettsia typhi) 和流行性斑疹伤寒 (R. prowazekii)。20 世纪的公共卫生干预导致发病率急剧下降；对当代 TGR 流行率知之甚少，因为这两种疾病都不是全国性的通报。我们总结了商业保险人群的行政索赔数据，以检查 TGR 医疗遭遇的趋势。我们分析了 2003 年至 2016 年 IBM® MarketScan® 商业数据库的数据，以识别具有国际疾病分类、第九或第十修订版、临床修改 TGR 特定代码的住院或门诊患者。我们总结了与事件诊断相关的流行病学特征。我们确定了 1,799 名被诊断为 TGR 的患者。患者居住在 46 个州，大多数为女性（n = 1,019/1,799；56.6%）；中位年龄为 42 岁（范围：0-64 岁）。流行性斑疹伤寒 (n = 931/1,799; 51.8%) 是最常见的 TGR，其次是鼠斑疹伤寒 (n = 722/1,799; 40.1%)。大多数 TGR 患者在门诊就诊（n = 1,725/1,799；95.9%）；在住院患者中，大多数被诊断为鼠斑疹伤寒（n = 67/74；90.5%）。TGRs 很少被诊断出疾病。尽管 R. prowazekii 传播需要体虱或飞鼠接触，但被诊断出患有流行性斑疹伤寒的患者多于鼠斑疹伤寒。来自所有地理区域的患者都被诊断出患有鼠类和流行性斑疹伤寒，尽管这些疾病的历史公认范围很广。