Recent Developments in the Diagnosis of Mucormycosis

Abstract

Mucormycosis is a potentially fatal infection that presents in different clinical forms and occurs in patients with various risk factors. Recently, the COVID-19 epidemic has been responsible for an increase in the incidence of mucormycosis, particularly in India. As with other invasive filamentous fungal infections, there are no specific clinical or radiological signs, and we have fewer diagnostic tools available than for other invasive fungal infections. Therefore, the diagnosis of Mucormycosis remains difficult. Nevertheless, for optimal management, early and accurate diagnosis is important. According to the latest recommendations, diagnosis is based on direct examination of clinical specimens, and/or histopathology, and culture. There are also molecular tools for direct detection from clinical specimens, but these techniques are moderately recommended. The main problems with these molecular techniques are that, until now, they were not very well standardized; there was a great heterogeneity of DNA targets and methods, which resulted in variable sensitivity. It is in this field that most advances have been made in the last two years. Indeed, recent studies have evaluated the performance and kinetics of Mucorales qPCR in serum and have shown good sensitivity and specificity. Large inter-laboratory evaluations of qPCR in serum have also been performed and have demonstrated good qualitative and quantitative reproducibility. These new results suggest the use of Mucorales qPCR as part of the diagnostic strategy for mucormycosis. One way to achieve better reproducibility could be to use commercial methods. Currently, there are at least three commercial qPCRs for Mucorales (MucorGenius from PathoNostics, MycoGenie from Ademtech, and Fungiplex from Bruker) that can be used to test serum, respiratory samples, or biopsies. However, to date, there has been little evaluation of these methods. Overall, Mucorales PCR in tissue samples, in respiratory samples, and in serum is promising and its addition as a diagnostic tool in the definitions of invasive mucormycosis should be discussed.

COVID-19-associated fungal infections in Iran: A systematic review

“…The rationale for the lack of data about species is that identifying mucormycosis agents to the level of genera and species for clinical management is not strongly supported by evidence, although recommended for epidemiological purposes [ 90 ]. Besides, culture has a low sensitivity (50%) to identify the species, and molecular techniques are not yet standardized and yield heterogeneous results [ 91 ].…”

Tracheal and Endobronchial Mucorales in a Young Liver Transplanted Patient: A Rare Condition

“…In our case, the Morales fungus was isolated and identified from an endotracheal expectoration seven days after the heatstroke. The main problem of these techniques is their lack of sensitivity, knowing that only fifty percent of cases appeared culture-positive [11]. For isolates obtained in culture, molecular identification seems more accurate than morphology [11].…”

“…The main problem of these techniques is their lack of sensitivity, knowing that only fifty percent of cases appeared culture-positive [11]. For isolates obtained in culture, molecular identification seems more accurate than morphology [11]. Antifungal susceptibility testing is recommended for better epidemiological knowledge but it is optional recommended for guiding treatment.…”

“…Histopathology is also strongly recommended. Immunohistochemistry is another possible tool, by using monoclonal antibodies, but must be performed by trained personnel and specialized laboratories [11]. The keys to a successful treatment involve three main aspects: consideration of risk factors and co-morbidities, early and aggressive surgical debridement of infected tissue if possible, and administration of antifungal therapy to control the spread of infection [12].…”

COVID-19 and Fungal infections: a double debacle

“…Of note, cultures often produce no growth, so the clinical context of the patient remains crucial to establishing a diagnosis. Moreover, detection of circulating DNA in the blood by quantitative PCR is a useful approach ( 151 , 152 ).…”