Rapid diagnosis of candidaemia by real-time PCR detection of Candida DNA in blood samples

Abstract

This study prospectively evaluated an 18S rRNA gene-targeted real-time PCR approach in comparison with standard blood culture (BC) diagnostics for rapid diagnosis of candidaemia in a large study population of 384 patients, including 902 whole blood samples from 468 infectious episodes (IEs) of 329 adults and 55 children with haematological malignancies and various forms of immunodeficiency, and intensive care unit patients. Seven out of eight BC-proven cases (87.5 %) of candidaemia and seven out of twelve BC-positive samples (58.3 %) were positive by the Candida-specific PCR. A positive PCR result was also obtained for 28/460 BC-negative samples from IEs, including 8 patients with culture-confirmed Candida infection at primary sterile body sites. Of the PCR-positive, culture-negative patients, more than 50 % received systemic antifungal therapy. In 432/460 BC-negative IEs, the Candida specific-PCR was negative, resulting in a negative predictive value of 99.8 %. In conclusion, the Candida specific-PCR approach facilitates rapid detection of Candida DNA in blood samples of patients at risk of candidaemia within a few hours. Although standard BC diagnostics appear to remain indispensable for the detection of all cases of candidaemia, this PCR assay allowed the detection of candidaemia at a mean of 3 days earlier than BC diagnostics. Thus, it enables earlier antifungal therapy for patients with suspected candidaemia and may prevent further complications.

Molecular and Nonmolecular Diagnostic Methods for Invasive Fungal Infections

“…Multiple studies have evaluated the performance of PCR tests for the diagnosis of invasive Candida infections in patient populations (4,118,(185)(186)(187)(188)(189)(190)(191)(192)(193)(194)(195)(196)(197)(198)(199)(200)(201)(202) (studies are summarized in Table 5). The ranges of reported sensitivity and specificity values are 56.2 to 100% and 54 to 100%, respectively.…”

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.…”

Candidiasis invasoras en recién nacidos: diagnóstico, tratamiento y prevención

“…-Examen micológico directo y cultivo de cualquier zona afectada según la evaluación clínica (líquido articular, líquido peritoneal, tejido obtenido por biopsia). -Las técnicas de diagnóstico molecular y determinación de antígenos están bajo evaluación en RN para complementar el diagnóstico de CI 23,24 .…”