血培养阳性时间可以作为导管相关性念珠菌血症的标志

David

Journal of Clinical Microbiology, July 2008, p. 2222-2226, Vol. 46, No. 7

Time to Blood Culture Positivity as a Marker for Catheter-Related Candidemia
血培养阳性时间可以作为导管相关性念珠菌血症的标志
Ronen Ben-Ami,1,5* Miriam Weinberger,3,5 Ruth Orni-Wasserlauff,1,2,5 David Schwartz,2 Avraham Itzhaki,3 Tzipora Lazarovitch,4 Edna Bash,2 Yuval Aharoni,2 Irina Moroz,1 and Michael Giladi1,2,5
Infectious Diseases Unit,1 Microbiology Laboratory, Tel Aviv Sourasky Medical Center, Tel Aviv,2 Infectious Diseases Unit,3 Microbiology Laboratory, Assaf Harofeh Medical Center, Zerifin,4 Sackler School of Medicine, Tel Aviv University, Ramat Aviv, Israel5

Received 2 February 2008/ Returned for modification 24 March 2008/ Accepted 5 May 2008

Candida spp. are important causes of nosocomial bloodstream infections. Around 80% of patients with candidemia have an indwelling central venous catheter (CVC). Determining whether the CVC is the source of candidemia has implications for patient management. We assessed whether the time to detection of Candida species in peripheral blood (time to positivity [TTP]) can serve as a marker for catheter-related candidemia. Prospective surveillance of Candida bloodstream infection was conducted in two medical centers. TTP was recorded by the BacT/Alert automated system. Sixty-four candidemia episodes were included. Fifty patients (78%) had an indwelling CVC. Thirteen patients (20.3%) had definite catheter-related candidemia. TTP was shorter for definite catheter-related candidemia (17.3 ± 2 h) than that for candidemia from other sources (38.2 ± 3 h; P < 0.001). A TTP cutoff of 30 h was 100% sensitive and 51.4% specific for catheter-related candidemia (area under the receiver-operator characteristic curve of 0.76). We conclude that TTP in peripheral blood is a sensitive but nonspecific marker for catheter-related candidemia and that a TTP of more than 30 h can help exclude an intravascular catheter as the possible source of candidemia.

Published ahead of print on 14 May 2008.

harmoni

珠菌（假丝酵母菌）是引起医院内血流感染的重要病原菌。约有80%的患者的中心静脉置管（CVC）患者存在有念珠菌的定植，而判定念珠菌血症是否源于CVC则牵涉到患者的管理问题。本研究致力于评价是否可以凭借外周血检出念珠菌的时间（培养阳性时间TTP）作为导管相关性念珠菌血症的诊断依据。本研究数据来源于对两个医学中心的血流感染念珠菌的前瞻性监测，以BacT/Alert 全自动血液培养仪记录的阳性时间为TTP。研究过程中有64个患者有念珠菌检出，其中50个患者（占75%）存在有中心静脉导管念珠菌定植，其中30个患者（20.3%）被诊断为导管相关性念珠菌血症。诊断为导管相关性念珠菌血症的患者TTP（17.3±2小时）较其他来源念珠菌血症的TTP(38.2 ± 3 小时; P < 0.001）短。若将导管相关念珠血症（受试者工作特征曲线下面积为0.76）的TTP设定为30小时，则其敏感性达到100%，特异性为51.4%。
本次研究结论为：1、TTP可以作为诊断导管相关性念珠血症的敏感性指标，但不能作为特异性指标。2、若TTP超过30小时，则有助于排外导管来源的念珠菌感染。
（译得不好，请指正。）