Comparison of Non-Culture-Based Methods for Detection of Systemic Fungal Infections, with an Emphasis on Invasive Candida Infections

Abstract

The accepted limitations associated with classic culture techniques for the diagnosis of invasive fungal infections have lead to the emergence of many non-culture-based methods. With superior sensitivities and quicker turnaround times, non-culture-based methods may aid the diagnosis of invasive fungal infections. In this review of the diagnostic service, we assessed the performances of two antigen detection techniques (enzyme-linked immunosorbent assay [ELISA] and latex agglutination) with a molecular method for the detection of invasive Candida infection and invasive aspergillosis. The specificities for all three assays were high (>97%), although the Candida PCR method had enhanced sensitivity over both ELISA and latex agglutination with values of 95%, 75%, and 25%, respectively. However, calculating significant sensitivity values for the Aspergillus detection methods was not feasible due to a low number of proven/probable cases. Despite enhanced sensitivity, the PCR method failed to detect nucleic acid in a probable case of invasive Candida infection that was detected by ELISA. In conclusion, both PCR and ELISA techniques should be used in unison to aid the detection of invasive fungal infections.

Multiplex Real-Time PCR Targeting the RNase P RNA Gene for Detection and Identification of Candida Species in Blood

“…These findings indicate that 3 to 4 ml of whole blood is more sensitive than 400 l of plasma. In other studies, detection of Candida from serum has been reported to be more sensitive than that from whole blood in some cases (1) but less so in others (7,24). Further, and well-designed, studies are needed to establish the optimal specimen type.…”

ECIL recommendations for the use of biological markers for the diagnosis of invasive fungal diseases in leukemic patients and hematopoietic SCT recipients

“…[42][43][44][45][46][47][48][49][50][51][52][53][54][55] The number of IC cases per study varied from 7 to 105, with a median of 25. A control group was included in 11 of 14 studies, and most frequently consisted of patients with similar risk factors but without IC, and sometimes with other documented infections.…”

Fungal DNA Detected in Blood Samples of Patients Who Received Contaminated Methylprednisolone Injections Reveals Increased Complexity of Causative Agents

“…We are not yet able to estimate the value of finding fungal DNA from patient blood in this outbreak, given the small sample size and the fact that there is little knowledge of the natural history of the infection, the fungal pathogenesis and innate host defense, or the therapeutic response and prognosis. However, detecting fungal DNA from blood is valuable in assisting rapid and accurate diagnosis for some types of invasive fungal infections, such as invasive candidiasis and invasive aspergillosis (13)(14)(15)(16). Regardless of sample size, 29 to 50% (depending on the cutoff) of tested blood being fungus positive indicated that having an insidious fungal infection may not be just an incidental event in this vulnerable population.…”