Loftus Randy W, Koff Matthew D, Brown Jeremiah R, Patel Hetal M, Jensen Jens T, Reddy Sundara, Ruoff Kathryn L, Heard Stephen O, Yeager Mark P, Dodds Thomas M
From the *Department of Anesthesiology, Dartmouth-Hitchcock Medical Center; †The Dartmouth Institute for Health Policy and Clinical Practice, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire; ‡Department of Anesthesiology, The University of Iowa Hospitals and Clinics, Iowa City, Iowa; §Department of Pathology, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire; and ∥Department of Anesthesiology, UMass Memorial Medical Center, Worcester, Massachusetts.
Anesth Analg. 2015 Apr;120(4):827-36. doi: 10.1213/ANE.0000000000000123.
Enterococci, the second leading cause of health care-associated infections, have evolved from commensal and harmless organisms to multidrug-resistant bacteria associated with a significant increase in patient morbidity and mortality. Prevention of ongoing spread of this organism within and between hospitals is important. In this study, we characterized Enterococcus transmission dynamics for bacterial reservoirs commonly encountered by anesthesia providers during the routine administration of general anesthesia.
Enterococcus isolates previously obtained from bacterial reservoirs frequently encountered by anesthesiologists (patient nasopharynx and axilla, anesthesia provider hands, and the adjustable pressure-limiting valve and agent dial of the anesthesia machine) at 3 major academic medical centers were identified as possible intraoperative bacterial transmission events by class of pathogen, temporal association, and phenotypic analysis (analytical profile indexing). They were then subjected to antibiotic disk diffusion sensitivity for transmission event confirmation. Isolates involved in confirmed transmission events were further analyzed to characterize the frequency, mode, origin, location of transmission events, and antibiotic susceptibility of transmitted pathogens.
Three hundred eighty-nine anesthesia reservoir isolates were previously identified by gross morphology and simple rapid tests as Enterococcus. The combination of further analytical profile indexing analysis and temporal association implicated 43% (166/389) of those isolates in possible intraoperative bacterial transmission events. Approximately, 30% (49/166) of possible transmission events were confirmed by additional antibiotic disk diffusion analysis. Two phenotypes, E5 and E7, explained 80% (39/49) of confirmed transmission events. For both phenotypes, provider hands were a common reservoir of origin proximal to the transmission event (96% [72/75] hand origin for E7 and 89% [50/56] hand origin for E5) and site of transmission (94% [16/17] hand transmission location for E7 and 86% [19/22] hand transmission location for E5).
Anesthesia provider hand contamination is a common proximal source and transmission location for Enterococcus transmission events in the anesthesia work area. Future work should evaluate the impact of intraoperative hand hygiene improvement strategies on the dynamics of intraoperative Enterococcus transmission.
肠球菌是医疗保健相关感染的第二大主要病因，已从共生无害微生物演变为多重耐药细菌，与患者发病率和死亡率的显著增加相关。预防这种微生物在医院内部和医院之间的持续传播很重要。在本研究中，我们描述了麻醉提供者在全身麻醉常规给药过程中常见的细菌储存库中肠球菌的传播动态。
先前从3个主要学术医疗中心的麻醉医生经常遇到的细菌储存库（患者鼻咽和腋窝、麻醉提供者手部以及麻醉机的可调压力限制阀和药物刻度盘）中获得的肠球菌分离株，通过病原体类别、时间关联和表型分析（分析谱索引）被确定为可能的术中细菌传播事件。然后对它们进行抗生素纸片扩散敏感性试验以确认传播事件。对参与确诊传播事件的分离株进行进一步分析，以描述传播事件的频率、模式、起源、传播位置以及传播病原体的抗生素敏感性。
先前通过大体形态和简单快速试验将389株麻醉储存库分离株鉴定为肠球菌。进一步的分析谱索引分析和时间关联相结合，表明这些分离株中有43%（166/389）可能参与术中细菌传播事件。通过额外的抗生素纸片扩散分析，约30%（49/166）的可能传播事件得到确认。两种表型E5和E7解释了80%（39/49）的确诊传播事件。对于这两种表型，提供者手部是传播事件近端常见的起源储存库（E7为96%[72/75]起源于手部，E5为89%[50/56]起源于手部）和传播部位（E7为94%[16/17]传播至手部，E5为86%[19/22]传播至手部）。
麻醉提供者手部污染是麻醉工作区域肠球菌传播事件常见的近端来源和传播部位。未来的工作应评估术中手部卫生改善策略对术中肠球菌传播动态的影响。
