Evaluation of noninvasive methods for the diagnosis of fungal endocarditis.

Fungal endocarditis (FE) is an uncommon disease with a high risk of morbidity and mortality. Here, we evaluated the different methods for diagnosing this infection. Cardiac valve, vegetation, and embolic materials obtained during surgery were examined for fungal infections by direct smear and culture. At least two blood samples were inoculated at the bedside into BACTEC medium. Galactomannan, mannan Ag enzyme-linked immunosorbent assay, and real-time polymerase chain reaction (PCR) assay were performed with serum samples. Of 25 patients with suspected infective endocarditis (IE), 8 were found to have proven FE according to the direct culture results. The etiologic agents were Aspergillus niger (three cases), A. flavus (two cases), A. fumigatus (one case), and Candida albicans (two cases). Blood culture was positive in only 1 case. The sensitivity, specificity, positive and negative predictive values, and positive and negative likelihood ratios of the results from the galactomannan test were 83.3%, 84.2%, 62.5%, 94.1%, 5.3, and 0.2; these same values, obtained from real-time PCR, were 87.5%, 94.4%, 87.5%, 94.4%, 15.6, and 0.14, respectively. Because mannan antigen was positive in samples from only one patient, we opted not to calculate the sensitivity. However, the specificity value in 23 cases without IE caused by Candida spp. was 100%. Based on our results, both the galactomannan test and real-time PCR can serve as reliable, noninvasive tests for the diagnosis of FE, compared with culture, which is considered to be the gold standard.

Incidence and outcome of documented fungal endocarditis.

BACKGROUND: Fungal endocarditis, the most severe form of infective endocarditis, is characterized by excessive mortality and morbidity. OBJECTIVES: The present study aimed to analyze the characteristics of fungal endocarditis to improve the management of these patients. MATERIALS AND METHODS: In this cross-sectional study, vegetations on the mitral or tricuspid valves and embolic material surgically removed from the patients with suspected infective endocarditis between December 2009 and November 2011 were examined for fungal infection by direct smear and culture, and the susceptibility patterns of the isolated species were determined. Then, blood samples were cultured on BACTEC media and real-time PCR was done with blood and tissue samples. RESULTS: Of the 31 patients with suspected infective endocarditis who did not respond to antibacterial therapy, 11 had confirmed fungal endocarditis. The most frequent predisposing risk factors were previous surgery and drug abuse. The organisms isolated were Aspergillus spp. and Candida albicans. Resistance to amphotericin B and itraconazole was observed in Aspergillus species, and to fluconazole in Candida albicans. Positive PCR results were obtained in blood and tissue samples. CONCLUSIONS: Fungal endocarditis should be considered in the patients not responsive to antimicrobials. Moreover, management of these patients can be improved with molecular diagnostic methods and by determining the susceptibility patterns of the etiologic agents.