Updated Definitions for Invasive Fungal Disease

The Infectious Diseases Group of the European Organization for Research and Treatment of Cancer and the Mycoses Study Group Education and Research Consortium (EORTC/MSGERC) have updated consensus definitions of invasive fungal diseases for use in clinical, diagnostic, and epidemiologic research, as published in Clinical Infectious Diseases.

The EORTC/MSGERC last updated consensus definitions of invasive fungal diseases in 2008. These definitions successfully served the original aim of allowing comparison of findings from studies on invasive fungal diseases, and have been adopted by regulatory agencies for evaluation of antifungals; however, these definitions were not intended to guide patient care, and were unsuitable for pediatric patients and patients with invasive fungal disease receiving care in the intensive care unit.

Therefore, EORTC/MSGERC volunteers were assigned, according to their area of expertise, to 10 working groups, with each group charged with appraising a particular topic. The volunteers closely examined imaging, laboratory diagnosis, and special populations at risk for invasive fungal diseases. The groups’ initial deliberations and recommendations were presented at the 7th Trends in Medical Mycology Conference in Lisbon, Portugal, in October 2015. Several rounds of discussion took place before a final version of the manuscript was approved.

There were no changes in the classifications of proven, probable, and possible invasive fungal diseases. However, the classification of probable was expanded and the scope of possible was diminished. Probable and possible invasive fungal diseases were proposed for patients who are immunocompromised (except for endemic mycoses), whereas proven invasive fungal diseases can apply to any patient, regardless of whether the patient is immunocompromised.

Recommendations were made for clear definitions for the diagnosis of invasive candidiasis and invasive pulmonary aspergillosis in pediatric patients via application of biomarker testing, and chest computerized tomography. The EORTC/MSGERC groups also made recommendations for the tailoring of the use of imaging modalities and biomarker tests to specific and appropriate suspected fungal infection. For example, diagnosis of pulmonary mucromycosis is better supported with high-resolution CT, compared with radiography, and magnetic resonance imaging. Similarly, the detection of (1,3)-beta-D glucan is suitable for a diagnosis of probably invasive fungal disease. Further, when fungal elements are identified on histopathology, the EORTC/MSGERC group recommends the use of polymerase chain reaction of fungal DNA to identify fungal genus and species.

“These revised definitions represent consensus expert opinion based on the best available evidence,” the researchers concluded. “As such, they will need to be reviewed regularly for their utility and relevance and, where possible, extended to other populations affected by [invasive fungal diseases]. We acknowledge the limitations of these definitions, including the exclusion of certain cases of [invasive fungal diseases]. However, the reliance on host factors, clinical features, and mycologic evidence to define [invasive fungal diseases] in selected populations has proven its value for clinical trials, epidemiologic studies, and the evaluation of diagnostic tests.”

Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.

Reference

Donnelly JP, Chen SC, Kauffman CA, et al. Revision and update of the consensus definitions of invasive fungal disease from the European Organization for Research and Treatment of Cancer and the Mycoses Study Group Education and Research Consortium [published online December 5, 2019]. Clin Infect Dis. doi: 10.1093/cid/ciz1008