Caulfield Adam J, Bolster LaSalle Catherine M, Chang Yu-Hui H, Grys Thomas E
Spectrum Health Regional Laboratory, Grand Rapids, Michigan.
Department of Laboratory Medicine and Pathology, Mayo Clinic Hospital, Phoenix, Arizona.
Diagn Microbiol Infect Dis. 2018 May;91(1):1-5. doi: 10.1016/j.diagmicrobio.2017.12.018. Epub 2018 Jan 3.
Detection of Clostridium difficile infection is important for clinical laboratories, owing to debilitating disease, severe outcomes, patient awareness, and public reporting of hospital data. This study evaluated the performance of 4 nucleic acid amplification test (NAAT) assays as part of a 2-step algorithm that involves reflexive NAAT following enzyme immunoassay (EIA) testing that is indeterminate for glutamate dehydrogenase (GDH) antigen and toxin A/B (GDH/toxin or GDH/toxin). A total of 500 stool specimens from consecutive patients were tested by each of the 5 methods and also evaluated as part of a 2-step algorithm. A specimen was considered positive for presence of C. difficile if it tested positive by 3 of 4 molecular methods or toxigenic culture. The sensitivity and specificity of the GDH-EIA method were each 93%. The toxin EIA had only 48% sensitivity, but it had 99% specificity. Sensitivity and specificity of 2-step algorithmic testing ranged from 88% to 93% and 99% to 100%, respectively, offering similar performance to stand-alone NAAT testing.
艰难梭菌感染的检测对临床实验室而言至关重要，这归因于该疾病会使人虚弱、导致严重后果、引起患者关注以及医院数据的公开报告。本研究评估了4种核酸扩增检测（NAAT）方法的性能，该评估是作为两步算法的一部分，此算法涉及在谷氨酸脱氢酶（GDH）抗原和毒素A/B（GDH/毒素或GDH/毒素）检测结果不确定的酶免疫测定（EIA）之后进行的反射性NAAT检测。通过这5种方法中的每一种对来自连续患者的总共500份粪便标本进行了检测，并作为两步算法的一部分进行了评估。如果一份标本通过4种分子方法中的3种或产毒培养检测呈阳性，则被认为艰难梭菌呈阳性。GDH-EIA方法的灵敏度和特异性均为93%。毒素EIA的灵敏度仅为48%，但其特异性为99%。两步算法检测的灵敏度和特异性分别为88%至93%和99%至100%，与单独的NAAT检测性能相似。
