Evaluation Of Three Diagnostic Methods For Invasive Candida Infection

Candida species are the most commer opportunistic pathogens including C.albicans, C.tropicalis, C.glabrata, C.parapsilosis and C.krusei. Candida often exist in the human body, mouth, throat, intestinal and vaginal mucosa, which could cause severe invasive candidiasis (invasive candidiasis, IC) in immune-compromised patients(including diabetes, organ transplantation, malignant tumor, blood disease, severe malnutrition), surgical patients and those who received broad-spectrum antibiotic therapy patients. According to the report, Invasive candidiasis are the most common invasive fungal infections,accounting for70-90%of all invasive fungal mycoses, and among the causes of nosocomial bloodstream infections,Candida ranks number four in the United States.Unfortunately, early diagnosis of invasive candidiasis remains a challenge, blood culture and sterile place specimen candida culture has been the"gold standard" of diagnosis of IC, but the sensitivity of this method is low. Although there are some serological method (antigen and antibody detection) is available, but these methods are not widely used in hospital, what’s more, the utility of the methods aslo need to be standardized and evaluated in a large number of patients. Foreign researchers on the basis of critically ill patients with risk factors, clinical manifestation and laboratory examination indexes, set up effective predicting surgical Intensive Care Unit (Intensive Care Unit, ICU) patients suffering from IC Candida scoring system (Candida Score, CS), the current domestic hospital has not yet been applied. The goal of the study was to evaluate the three methods, Candida Score method, the method to measure the Anti-Eno in serum, measurement of the (1-3)-beta-D-glucan(BG) in early diagnosis of IC.ObjectiveTo compare and evaluate of candida score, Anti-Eno detection, BG in early diagnosis of IC.Methods1. Measurement of anti-Eno ELISA assay The case data was collected from June2011to May2013in a surgery ICU, collected the plasma specimen, and detected Anti-Eno by ELISA method. Collected all kinds of blood, urine, sputum, bile, pus, central venous catheter, secretion, puncture and various swab specimens for culture, identification and drug sensitive test.2. BG testAnother group paitents were selected from October2012to August2013those who were recieved BG test, collected the plasma specimen, use BG test method for detecting (1-3)-beta-D-glucan, and detected Anti-Eno by ELISA method. All of the detecting results were comparated to fungus culture results.3. CSCombined with the practical situation of the clinical diagnosis and treatment, the CS was calculated as follows (variables coded as absent=0, present=l):total parenteral nutrition×1, plus surgery×1, plus multifocal Candida colonization×1, plus severe sepsis×2. And compared CS results with antibody detection results.ResultsFor the307cases of ICU patients,68patients with Anti-Eno detection of positive results, the fungus culture method in34patients confirmed IC, the sensitivity of antibody detection was higher than fungus culture method.21cases confirmed positive anti-Eno IC patients (61.8%); Among these patients,12cases (57.1%) antibody positive results in candida positive training report before2-25days. Patients treated with glucocorticoid could interference the anti-Eno detection results.210patients had both the BG test and detection of anti-Eno results,15patients were confirmed IC;54patients(25.7%) had tested as positive for BG, including5patients were confirmed IC;33patients(15.7%) had tested as positive for detecting anti-Eno,which aslo including7patients were confirmed IC. Detection anti-Eno of sensitivity, specificity, positive predictive value, negative predictive value are:46.7%(7/15),86.7%(169/195),21.2%(7/33),95.5%(169/177), respectively. BG diagnosis of IC, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) were33.3%(5/15),74.9.0%(146/195),9.3%(5/54),93.6%(146/156), respectively. The sensitivity, specificity, positive predictive value, negative predictive value of anti-Eno were higher than G test.We defined Candida Score method cut off of CS=3, The sensitivity, specificity, positive predictive value, negative predictive value of prediction of surgical ICU patients suffering from IC were97.1%,59.0%,22.8%,99.4%, respectively. Compared with detection of anti-Eno, the sensitivity of Candida Scoring was higher (97.1%vs61.8%), but its specificity and positive predictive value is lower than the detection of anti-Eno method (59.0%vs82.8%,59.0%vs82.8%).ConclusionsAnti-Eno rised before infection, which could become a useful marker in diagnosising of IC due to its high sensitivity and specificity. Combined the use of BG test, detecting Anti-Eno and fungal culture could greatly improve the level of the diagnosis of invasive candida. Our results suggest that Candidia score could be a protental tool in early diagnosing IC for patients in ICU, and the Candidia score criteria would provide reference for clinical antifugal treatment. However, its predictive value in diffierent underlying dieases patients has significant differences.