Irigoyen-von-Sierakowski Álvaro, Díaz-Navarro Marta, Visedo Andrés, Pérez-Granda María Jesús, Martín-Rabadán Pablo, Muñoz Patricia, Guembe María
Department of Clinical Microbiology and Infectious Diseases, Hospital General Universitario Gregorio Marañón, Madrid, Spain.
Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain.
Microbiol Spectr. 2025 Jun 3;13(6):e0267824. doi: 10.1128/spectrum.02678-24. Epub 2025 Apr 8.
The differential time to positivity (DTTP) technique is the recommended conservative procedure to diagnose catheter-related bloodstream infection (C-RBSI). However, its reliability and accuracy remain under debate. Therefore, we aimed to compare the DTTP technique feasibility to detect C-RBSI compared to the catheter culture (CC) method. We conducted a 9-month retrospective study including bacteremic episodes in which both DTTP blood cultures (BC) and CC were obtained. We analyzed the diagnostic validity of the DTTP technique for detecting C-RBSI compared to the gold standard (C-RBSI with CC), along with patient clinical data. We included 37 episodes of C-RBSI where both DTTP BC and CC were obtained. C-RBSI was confirmed by both techniques in only 13 episodes (35.1%), whereas in 11 (29.7%) and 13 (35.1%), only DTTP BC or DTTP BC with CC (with a difference between catheter lumen and peripheral BC growth of <2 hours) was positive, respectively. Therefore, the validity values of the DTTP technique for predicting C-RBSI were as follows: sensitivity, 50.0%; specificity, 71.8%; positive predictive value, 54.2%; and negative predictive value, 68.3%. The distribution of microorganisms was similar among the three groups. All patients in whom colonization was not demonstrated by CC ( = 11) had been receiving antibiotics before catheter withdrawal. DTTP is a conservative technique that might help to diagnose C-RBSI mostly in situations where catheter removal cannot be achieved. However, it should be interpreted with caution and never be used to rule out C-RBSI. CC before starting antimicrobial therapy remains the most reliable method to diagnose and confirm an episode of C-RBSI.IMPORTANCEWe try to clarify the reliability of the differential time to positivity technique to predict C-RBSI. It may be interpreted with caution and considering clinical signs, as some C-RBSI can be misdiagnosed.
阳性时间差（DTTP）技术是诊断导管相关血流感染（C-RBSI）推荐使用的保守方法。然而，其可靠性和准确性仍存在争议。因此，我们旨在比较DTTP技术与导管培养（CC）方法检测C-RBSI的可行性。我们进行了一项为期9个月的回顾性研究，纳入了同时进行DTTP血培养（BC）和CC的菌血症发作病例。我们分析了与金标准（CC确诊的C-RBSI）相比，DTTP技术检测C-RBSI的诊断有效性，以及患者的临床数据。我们纳入了37例同时进行DTTP BC和CC的C-RBSI发作病例。两种技术均确诊C-RBSI的仅有13例（35.1%），而仅DTTP BC阳性的有11例（29.7%），DTTP BC与CC均阳性（导管腔与外周血培养生长时间差<2小时）的有13例（35.1%）。因此，DTTP技术预测C-RBSI的有效性值如下：敏感性为50.0%；特异性为71.8%；阳性预测值为54.2%；阴性预测值为68.3%。三组间微生物分布相似。CC未显示有定植的所有患者（n = 11）在拔除导管前均接受了抗生素治疗。DTTP是一种保守技术，主要在无法拔除导管的情况下可能有助于诊断C-RBSI。然而，其结果应谨慎解读，绝不能用于排除C-RBSI。开始抗菌治疗前进行CC仍然是诊断和确诊C-RBSI发作最可靠的方法。重要性我们试图阐明阳性时间差技术预测C-RBSI的可靠性。由于可能会误诊一些C-RBSI，因此应谨慎解读并结合临床体征进行考虑。
