BACKGROUND Non-toxigenic Corynebacterium diphtheriae (C. diphtheriae), often associated with wounds, can rarely cause infective endocarditis (IE). Five patients with C. diphtheriae IE were identified within 12 months at a Seattle-based hospital system. We reviewed prior C. diphtheriae positive cultures to determine if detections had increased over time and evaluated epidemiologic trends. METHODS We conducted a formal electronic health record search to identify all patients ≥ 18 years of age with C. diphtheriae detected in a clinical specimen (i.e. wound, blood, sputum) between September 1, 2020–April 1, 2023. We collected patient demographics, housing status, comorbidities, substance use history and level of medical care required at detection. We extracted laboratory data on susceptibilities of C. diphtheriae isolates, and on other pathogens detected at the time of C. diphtheriae identification. RESULTS Between September 1, 2020–April 1, 2023, 44 patients (median age 44 years) had a C. diphtheriae-positive clinical culture, with most detections occurring after March 2022. Patients were predominantly male (75%), White (66%), unstably housed (77%), and had a lifetime history of injecting drugs (75%). Most C. diphtheriae positive cultures were polymicrobial, including wound cultures from 36 (82%) patients and blood cultures from 6 (14%) patients, not mutually exclusive. Thirty-four patients (77%), including all five patients with C. diphtheriae IE, required hospital admission for C. diphtheriae or a related condition. Of the five patients with IE, three died of IE and one from COVID-19. CONCLUSION Findings suggest a high-morbidity outbreak disproportionately affecting patients who use substances and are unstably housed.

中文翻译：

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非产毒白喉棒状杆菌感染性心内膜炎群和背景白喉棒状杆菌病例不断增加——2020-2023 年华盛顿州西雅图

背景技术非产毒白喉棒状杆菌（C. diphtheriae）通常与伤口有关，很少引起感染性心内膜炎（IE）。12 个月内，西雅图的一家医院系统发现了 5 名患有白喉棒状杆菌 IE 的患者。我们回顾了之前的白喉杆菌阳性培养物，以确定检测结果是否随着时间的推移而增加，并评估了流行病学趋势。方法 我们进行了正式的电子健康记录检索，以识别 2020 年 9 月 1 日至 2023 年 4 月 1 日期间在临床标本（即伤口、血液、痰）中检测到的所有 18 岁以上患有白喉杆菌的患者。我们收集了患者的人口统计数据、住房状况、合并症、药物使用史以及检测时所需的医疗护理水平。我们提取了白喉棒状杆菌分离株的敏感性以及白喉棒状杆菌鉴定时检测到的其他病原体的实验室数据。结果 2020 年 9 月 1 日至 2023 年 4 月 1 日期间，44 名患者（中位年龄 44 岁）的临床培养结果呈白喉杆菌阳性，大多数检测发生在 2022 年 3 月之后。患者主要为男性（75%）、白人（66 %），居住环境不稳定（77%），并且有终生注射毒品史（75%）。大多数白喉杆菌阳性培养物是多种微生物，包括 36 名 (82%) 患者的伤口培养物和 6 名 (14%) 患者的血培养物，并不相互排斥。34 名患者 (77%)，包括所有 5 名白喉棒状杆菌 IE 患者，因白喉棒状杆菌或相关病症需要入院。在 5 名 IE 患者中，3 名死于 IE，1 名死于 COVID-19。结论 研究结果表明，高发病率疫情对使用药物和居住不稳定的患者造成了不成比例的影响。