A Predictive Model for Diagnosis of Acute Invasive Fungal Rhinosinusitis Among High-Risk Patients

BackgroundAcute invasive fungal rhinosinusitis (AIFR) is a life-threatening disease mainly affecting immunocompromised patients. Early detection is therefore key to improving patient survival. To date, there are still no standard clinical criteria for AIFR diagnosis.ObjectiveThis study develops a predictive model that utilizes clinical presentation and computed tomography (CT) findings to diagnose AIFR.MethodsA retrospective cohort study was conducted on patients with high risk for AIFR at King Chulalongkorn Memorial Hospital over the past 15 years (2008-2022). We constructed several multivariate logistic regression models for AIFR diagnosis based on different subsets of variables from 3 categories: signs/symptoms, endoscopy, and CT imaging.ResultsThere were 67 AIFR-positive patients and 68 AIFR-negative patients. Combining variables from 3 categories, a 6-variable model (fever, visual loss, mucosal discoloration, crusting, mucosal loss of contrast, retroantral fat stranding) achieved the highest area under the receiver operating characteristic curve of 0.8900 (74.63% sensitivity, 89.71% specificity).ConclusionsWe proposed predictive models for AIFR diagnosis in high-risk patients using clinical variables. The models can be used to guide the decision for further management such as biopsy or surgical intervention.

Contribution of paranasal sinus, chest, and abdomen/pelvis computed tomography in patients with febrile neutropenia

OBJECTIVE

Febrile neutropenia (FN) is a serious clinical event, associated with significant morbidity and mortality. Imaging has a central role in the identification of the fever cause. The study objectives were to assess abnormalities of potential infectious origin on paranasal sinus, chest and abdomen/pelvis CT scans performed during an episode of FN, in patients with or without specific clinical signs, and to evaluate their impact on the frequency of changes in treatment.

MATERIALS AND METHODS

This retrospective study included 306 patients with FN from a single academic center between October 2018 and December 2019. Clinical and biological data, final clinical diagnosis for the FN episode, and change in treatment following CT scans were collected from medical records. CT images were reviewed for positive findings in each anatomical region.

RESULTS

Overall, 188 patients (61.4%) had at least one positive CT finding on paranasal sinus, chest and/or abdomen/pelvis regions, and 153 patients (50.0%) received a final clinical diagnosis of infection, based on microbiological and/or radiological findings. There were more chest and abdomen/pelvis CT positive findings in patients with specific clinical signs than in patients without (65.7% vs. 25.8%, and 59.0% vs. 22.7% respectively, p <0.001), with a higher frequency of therapeutic modifications in positive CTs. There were significantly more paranasal sinus CT abnormalities in symptomatic patients (33.3% vs. 8.5%, p = 0.03), but without any impact on treatment.

CONCLUSION

These results support recommendations to perform systematic chest CT in patients with FN and may encourage the widespread use of abdomen/pelvis CT in this indication, even without symptoms. However, the actual impact of their use on the prognosis of the patients remains to be evaluated.

The first report of rhinosinusitis by Rhizopus delemar in a patient with severe COVID-19 in Iran: a case report

BACKGROUND

Mucormycosis is a severe and fatal fungal infection in patients with coronavirus disease 2019 caused by Mucorales. Here we present a case of a 63-year-old man with coronavirus disease 2019 infection, along with rhinosinusitis mucormycosis caused by Rhizopus delemar.

CASE PRESENTATION

A 63-year-old Iranian man suffering from a coronavirus disease 2019 infection with symptoms of cough, shortness of breath, and generalized body pain. On the basis of the clinical manifestations, such as headache, a history of black nasal discharge, nasal hypoesthesia, facial swelling, numbness, nasal obstruction, presence of necrotic lesions on the nasal passages on physical examination, and abnormal computed tomography scans of paranasal sinuses, the patient underwent surgical debridement. Direct microscopy of specimens obtained from the paranasal sinuses, and subsequent isolation and identification, revealed a rhinosinusitis mucormycosis caused by R. delemar. Despite therapeutic measures, such as sinus debridement surgery and antifungal therapy with amphotericin B injection (50 mg/day), the patient died after 35 days of hospitalization.

CONCLUSION

In this report, we present the first documented case of human infection with R. delemar in a patient with coronavirus disease 2019 infection, who also exhibited rhinosinusitis mucormycosis. R. delemar appears to be an emerging agent of rhinosinusitis mucormycosis in this region. Furthermore, prompt diagnosis and the exploration of alternative antifungal treatments, beyond amphotericin B, may be crucial for effectively managing patients with R. delemar infections.

Invasive fungal sinusitis: A comparison of pediatric versus adult cases

BACKGROUND

Invasive fungal sinusitis (IFS) is a rare infection with high mortality, mainly impacting immunocompromised patients. Given its significant mortality, timely recognition and treatment is crucial. This study aims to highlight the differences in presentation of IFS between pediatric and adult patients to aid in prompt diagnosis and treatment of this condition.

METHODS

A comprehensive literature search of PubMed, EMBASE, Web of Science, Global Index Medicus, Global Health (EBSCO) and Cochrane Database of Systematic Reviews was conducted to identify articles relating to IFS. Patient demographics, comorbidities, presentation, disease characteristics, treatments and outcomes were extracted from the studies, and statistical analyses were conducted to compare these variables between pediatric and adult patients.

RESULTS

111 studies identified 22 pediatric and 132 adult patients worldwide. Children were more likely to have hematologic malignancies compared to adults (59.1 % vs. 15.2 %, p < 0.001). Facial symptoms such as pain, edema, and numbness were the most common symptoms for both age groups. In the pediatric population, fever and nasal or oral mucosal lesions were more common presenting symptoms (both p < 0.001). Pediatric patients were more likely to present without disease extension beyond the sinuses (p < 0.001). There was no significant difference in either medication treatment or mortality between the two cohorts.

CONCLUSION

IFS often presents with non-specific symptoms and a unique presentation in pediatric and adult populations. Clinical awareness of the varying presentations in both populations is important to treat in a timely manner given the rapid progression and high mortality rates of IFS.

Serial Quantitation of Plasma Microbial Cell-Free DNA Before and After Diagnosis of Pulmonary Invasive Mold Infections After Hematopoietic Cell Transplant

BACKGROUND

Plasma microbial cell-free DNA sequencing (mcfDNA-Seq) is a noninvasive test for microbial diagnosis of invasive mold infection (IMI). The utility of mcfDNA-Seq for predicting IMI onset and the clinical implications of mcfDNA concentrations are unknown.

METHODS

We retrospectively tested plasma from hematopoietic cell transplant (HCT) recipients with pulmonary IMI and ≥1 mold identified by mcfDNA-Seq in plasma collected within 14 days of clinical diagnosis. Samples collected from up to 4 weeks before and 4 weeks after IMI diagnosis were evaluated using mcfDNA-Seq.

RESULTS

Thirty-five HCT recipients with 39 IMIs (16 Aspergillus and 23 non-Aspergillus infections) were included. Pathogenic molds were detected in 38%, 26%, 11%, and 0% of samples collected during the first, second, third, and fourth week before clinical diagnosis, respectively. In non-Aspergillus infections, median mcfDNA concentrations in samples collected within 3 days of clinical diagnosis were higher in infections with versus without extrapulmonary spread (4.3 vs 3.3 log10 molecules per microliter [mpm], P = .02), and all patients (8/8) with mcfDNA concentrations >4.0 log10 mpm died within 42 days after clinical diagnosis.

CONCLUSIONS

Plasma mcfDNA-Seq can identify pathogenic molds up to 3 weeks before clinical diagnosis of pulmonary IMI. Plasma mcfDNA concentrations may correlate with extrapulmonary spread and mortality in non-Aspergillus IMI.

Practical issues related to non-Aspergillus invasive mold infections

Infection by non-Aspergillus molds has been increasingly reported. The management of such infections is challenging both for diagnosis and treatment, including the need of well-trained mycologists to properly identify rare fungi, difficulties in distinguishing between contamination, colonization and infection, the lack of randomized studies comparing different drugs or regimens, poor activity of available antifungal agents, lack of correlation between in vitro antifungal susceptibility tests and clinical outcome, and poor prognosis. Mucormycosis and fusariosis are the most frequent non-Aspergillus mold infections. Mucormycosis occurs more frequently in four major groups of patients: solid organ transplant recipients, patients with hematologic malignancies receiving chemotherapy or hematopoietic cell transplantation, diabetic patients, and immunocompetent individuals who suffer various types of skin and soft tissue trauma. Invasive fusariosis occurs almost exclusively in patients with hematologic malignancies. In this review we discuss practical issues related to the management of these and other non-Aspergillus mold infections.

Hemoptysis in Cancer Patients

Hemoptysis in cancer patients can occur for various reasons, including infections, tumors, blood vessel abnormalities and inflammatory conditions. The degree of hemoptysis is commonly classified according to the quantity of blood expelled. However, volume-based definitions may not accurately reflect the clinical impact of bleeding. This review explores a more comprehensive approach to evaluating hemoptysis by considering its risk factors, epidemiology and clinical consequences. In particular, this review provides insight into the risk factors, identifies mortality rates associated with hemoptysis in cancer patients and highlights the need for developing a mortality prediction score specific for cancer patients. The use of hemoptysis-related variables may help stratify patients into risk categories; optimize the control of bleeding with critical care; implement the use of tracheobronchial or vascular interventions; and aid in treatment planning. Effective management of hemoptysis in cancer patients must address the underlying cause while also providing supportive care to improve patients' quality of life.

Clinical Features and Treatment Progress of Invasive Mucormycosis in Patients with Hematological Malignancies

The incidence rate of invasive mucormycosis (IM) in patients with hematological malignancies (HMs) is increasing year by year, ranging from 0.07% to 4.29%, and the mortality rate is mostly higher than 50%. With the ongoing pandemic of COVID-19, COVID-19-associated mucormycosis (CAM) also became a global health threat. Patients with high risk factors such as active HMs, relapsed/refractory leukemia, prolonged neutropenia may still develop breakthrough mucormycosis (BT-MCR) even under the prophylaxis of Mucorales-active antifungals, and such patients often have higher mortality. Rhizopus spp. is the most common genus associated with IM, followed by Mucor spp. and Lichtheimia spp. Pulmonary mucormycosis (PM) is the most common form of IM in patients with HMs, followed by rhino-orbital-cerebral mucormycosis (ROCM) and disseminated mucormycosis. The prognosis of IM patients with neutrophil recovery, localized IM and receiving early combined medical-surgical therapy is usually better. As for management of the disease, risk factors should be eliminated firstly. Liposome amphotericin B (L-AmB) combined with surgery is the initial treatment scheme of IM. Those who are intolerant to L-AmB can choose intravenous formulations or tablets of isavuconazole or posaconazole. Patients who are refractory to monotherapy can turn to combined antifungals therapy.

A case report of brainstem hemorrhage due to Rhizopus delemar-induced encephalitis diagnosed by metagenomic next-generation sequencing (mNGS)

BACKGROUND

Rhizopus delemar is an invasive fungal pathogen that can cause fatal mucormycosis in immunodeficient individuals. Encephalitis caused by R. delemar is rare and difficult to diagnose early. Clinical detection methods for R. delemar include blood fungal culture, direct microscopic examination, and histopathological examination, but the detection is often inadequate for clinical diagnosis and can easily lead to missed diagnosis with delayed treatment.

CASE PRESENTATION

We report a case of a 47-year-old male with brainstem hemorrhage caused by encephalitis due to R. delemar. The patient had a history of hypertension, type 2 diabetes, and irregular medication. No pathogens were detected in cerebrospinal fluid (CSF) and nasopharyngeal secretion cultures. R. delemar was identified by metagenomic next-generation sequencing (mNGS) in CSF, and in combination with the patient's clinical characteristics, encephalitis caused by R. delemar was diagnosed. Antibiotic treatment using amphotericin B liposome in combination with posaconazole was given immediately. However, due to progressive aggravation of the patient's symptoms, he later died due to brainstem hemorrhage after giving up treatment.

CONCLUSIONS

mNGS technique is a potential approach for the early diagnosis of infections, which can help clinicians provide appropriate antibiotic treatments, thus reducing the mortality and disability rate of patients.

SARS-CoV-19-associated Rhino-orbital and cerebral Mucormycosis: Clinical and Radiological Presentations

We describe presenting clinical and imaging manifestations of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2)-associated Rhino-oculo-cerebral mucormycosis (ROCM) in a hospital setting during the second wave of SARS-CoV-2 pandemic in India. Data on the presenting manifestations were collected from 1 March to 31 May 2021. Associations between clinical and imaging findings were explored, specifically: (1) the presence or absence of orbital pain and infiltration of a superior orbital fissure on imaging; (2) the presence of unilateral facial nerve palsy and pterygopalatine fossa infiltration and geniculate ganglion signal on contrast magnetic resonance imaging, and (3) vision loss and optic nerve findings on imaging. Orbital pain was reported by 6/36 subjects. A fixed, frozen eye with proptosis and congestion was documented in 26 (72%), complete vision loss in 23 (64%), and a unilateral lower motor neuron facial nerve palsy in 18 (50%). No association was found between the presence of orbital pain and superior orbital fissure infiltration on imaging. The ipsilateral geniculate ganglion was found to enhance more profoundly in 7/11 subjects with facial palsy and available magnetic resonance (MR) imaging, and the ipsilateral pterygopalatine fossa was found infiltrated in 14. Among 23 subjects with complete loss of vision, 9 (39%) demonstrated long-segment bright signal in the posterior optic nerve on diffusion MR images. We conclude that orbital pain might be absent in SARS-CoV-2-associated ROCM. Facial nerve palsy is more common than previously appreciated and ischemic lesions of the posterior portion of the optic nerve underlie complete vision loss.

Targeted Delivery of Antifungal Liposomes to Rhizopus delemar

Mucormycosis (a.k.a. zygomycosis) is an often-life-threatening disease caused by fungi from the ancient fungal division Mucoromycota. Globally, there are nearly a million people with the disease. Rhizopus spp., and R. delemar (R. oryzae, R. arrhizus) in particular, are responsible for most of the diagnosed cases. Pulmonary, rhino-orbito-cerebral, and invasive mucormycosis are most effectively treated with amphotericin B (AmB) and particularly with liposomal formulations (e.g., AmBisome^®). However, even after antifungal therapy, there is still a 50% mortality rate. Hence, there is a critical need to improve therapeutics for mucormycosis. Targeting AmB-loaded liposomes (AmB-LLs) with the pathogen receptor Dectin-1 (DEC1-AmB-LLs) to the beta-glucans expressed on the surface of Aspergillus fumigatus and Candida albicans lowers the effective dose required to kill cells relative to untargeted AmB-LLs. Because Dectin-1 is an immune receptor for R. delemar infections and may bind it directly, we explored the Dectin-1-mediated delivery of liposomal AmB to R. delemar. DEC1-AmB-LLs bound 100- to 1000-fold more efficiently to the exopolysaccharide matrix of R. delemar germlings and mature hyphae relative to AmB-LLs. DEC1-AmB-LLs delivering sub-micromolar concentrations of AmB were an order of magnitude more efficient at inhibiting and/or killing R. delemar than AmB-LLs. Targeted antifungal drug-loaded liposomes have the potential to improve the treatment of mucormycosis.

Pulmonary Artery Pseudoaneurysm in COVID-19-Associated Pulmonary Mucormycosis: Case Series and Systematic Review of the Literature

Literature on COVID-19-associated pulmonary mucormycosis (CAPM) is sparse. Pulmonary artery pseudoaneurysm (PAP) is an uncommon complication of pulmonary mucormycosis (PM), and rarely reported in CAPM. Herein, we report five cases of CAPM with PAP managed at our center and perform a systematic review of the literature. We diagnosed PM in those with clinico-radiological suspicion and confirmed it by microbiology or histopathology. We encountered five cases of CAPM with PAP (size ranged from 1 × 0.8 cm to ~ 4.9 × 4.8 cm). All subjects had diabetes and were aged 55–62 years (75% men). In two cases, COVID-19 and mucormycosis were diagnosed simultaneously, while in three others, COVID-19 preceded PM. One subject who underwent surgery survived, while all others died (80% mortality). From our systematic review, we identified one additional case of CAPM with PAP in a transplant recipient. CAPM with PAP is rare with high mortality. Early diagnosis and multimodality management are imperative to improve outcomes.

Characteristics of Mucormycosis in Hematological Patients and a Death Prediction Model

Mucormycosis is an angioinvasive fungal infection, associated with high mortality. The aim of our study was to explore the high-risk factors and predict the death of hematological disease complicated with mucormycosis. We retrospectively analyzed clinical data of 31 patients with hematological disease complicated with mucormycosis, adopted random forest to establish the death prediction model, and validated the model in another 15 patients. The median age of the 31 cases was 46 (28–51) years, male to female ratio 1.38:1, and 90-day mortality rate 54.8%. The most common underlying disease was acute myeloid leukemia (58.1%). The main clinical symptoms were fever (100%), cough (87.1%), sputum (80.6%), chest pain (61.3%), and hemoptysis (19.4%). Reversed halo sign (83.9%) was the most common computed tomography sign. A total of 48.4% of patients also had aspergillus or bacterial infections. Discriminative models were constructed by random forest with 17 non-survivors and 14 survivors. Procalcitonin, the duration of intravenous administration of amphotericin B or amphotericin B liposomes, and neutropenia at death or 90 days of survival were the leading risk factors for poor prognosis, with area under the curve of 0.975 (95% CI 0.934–1). We chose 0.6775 as death prediction threshold (with 82.3% sensitivity and 100% specificity) and validated the model successfully in another 15 patients. Chest pain and reversed halo sign are specific clinical and image signs of hematological disease complicated with mucormycosis. Neutropenia, elevated procalcitonin, and insufficient use time of amphotericin B or amphotericin B liposomes are risk factors for death.

Role of flexible bronchoscopy in the diagnosis of invasive fungal infections

BACKGROUND

There are sparse data on the role of flexible bronchoscopy (FB) in diagnosing invasive mould infections (IMIs).

OBJECTIVE

To investigate the safety and usefulness of FB in IMI. We evaluate the factors associated with a successful diagnosis of IMI using FB. Further, we compare subjects of invasive pulmonary aspergillosis (IPA) with pulmonary mucormycosis (PM).

METHODS

We retrospectively reviewed the clinical features, imaging data, bronchoscopy, microbiology and pathology details of subjects who underwent FB for suspected IMI. We categorised FB as diagnostic if it contributed to the diagnosis of IMI. We performed a multivariate analysis to identify the factors associated with a diagnostic bronchoscopy.

RESULTS

Of the 3521 FB performed over 18 months, 132 (3.7%) were done for suspected IMIs. We included 107 subjects for the final analysis. The risk factors for IMI included renal transplantation (29.0%), diabetes (27.1%), haematological malignancy (10.3%) and others. We found bronchoscopic abnormalities in 33 (30.8%) subjects, and these were more frequent in those with confirmed PM (67%) than IPA (27%). IMI was confirmed in 79 (14 proven, 48 probable and 17 possible) subjects. FB was diagnostic in 71%. We experienced major complications in three cases (2.7%), including one death. On multivariate analysis, the visualisation of endobronchial abnormalities during FB (OR [95%, CI], 8.5 [1.4-50.4]) was the only factor associated with a diagnostic FB after adjusting for age and various risk factors.

CONCLUSIONS

Flexible bronchoscopy is a useful and safe procedure in diagnosing IMIs. The presence of endobronchial abnormalities predicts a successful diagnostic yield on FB.

Has the mortality from pulmonary mucormycosis changed over time? A systematic review and meta-analysis

OBJECTIVES

Pulmonary mucormycosis (PM) is increasingly being reported in immunocompromised patients and has a high mortality. Our aim was to assess the mortality of PM and its trend over time. We also evaluated the role of combined medical-surgical therapy in PM.

METHODS

We performed a systematic review of Pubmed, Embase, and Cochrane central databases. Studies were eligible if they described at least five confirmed cases of PM and reported mortality. We also assessed the effect of combined medical-surgical therapy versus medical treatment alone on PM mortality. We used a random-effects model to estimate the pooled mortality of PM and compared it across three time periods. The factors influencing mortality were assessed using meta-regression. We evaluated the risk difference (RD) of death in the following: subjects undergoing combined medical-surgical therapy versus medical therapy alone, subjects with isolated PM versus disseminated disease, and PM in diabetes mellitus (DM) versus non-DM as a risk factor.

RESULTS

We included 79 studies (1544 subjects). The pooled mortality of PM was 57.1% (95% confidence interval [CI] 51.7-62.6%). Mortality improved significantly over time (72.1% versus 58.3% versus 49.8% for studies before 2000, 2000-2009, and 2010-2020, respectively, p 0.00001). This improved survival was confirmed in meta-regression after adjusting for the study design, the country's income level, and the sample size. Combined medical-surgical therapy was associated with a significantly lower RD (95%CI) of death: -0.32 (-0.49 to -0.16). The disseminated disease had a higher risk of death than isolated PM, but DM was not associated with a higher risk of death than other risk factors.

CONCLUSIONS

While PM is still associated with high mortality, we noted improved survival over time. Combined medical-surgical therapy improved survival compared to medical treatment alone.

Developments in identifying and managing mucormycosis in hematologic cancer patients

INTRODUCTION

Mucormycoses represent a rare but very aggressive class of mold infections occurring in patients with hematological malignancies (HMs). In the past, patients at high risk of invasive mucomycosis (IM) were those affected by acute myeloid leukemia but over the last ten years the prophylaxis with a very effective mold-active drug, such as posaconazole, has completely modified the epidemiology. In fact, IM is now observed more frequently in patients with lymphoproliferative disorders who do not receive antifungal prophylaxis.

AREAS COVERED

The attention was focused on the epidemiology, diagnosis, prophylaxis and treatment of IM in HMs. Authors excluded pediatric patients considering the different epidemiology and differences in treatment given the limitation of the use of azoles in the pediatric field. A systematic literature review was performed using PubMed database listings between February 2014 and February 2020 using the following MeSH terms: leukemia, hematological malignancies, stem cell transplantation, mucormycosis, molds, prophilaxis, treatment.

EXPERT OPINION

The epidemiology of mucormycosis in HMs is changing in the last years. The availability of drugs more effective than in the past against this infection has reduced the mortality; however, a timely diagnosis remains a relevant problem potentially influencing the outcome of hematologic patients with IM.

Special Staining of the Liquid-Based Cytopathology Test in Bronchoalveolar Lavage Fluid for Diagnosis of Invasive Pulmonary Aspergillosis with Nonneutropenic Patients

In recent years, various biomarkers have been gradually applied on bronchoalveolar lavage (BAL) fluid for the diagnosis of invasive pulmonary aspergillosis (IPA). The objective of this study is to assess the value of the liquid-based cytopathology test (LCT) for improving the identification of IPA in BAL fluid from possible IPA patients, following special staining with periodic acid-Schiff staining (PAS) or Grocott's methenamine silver (GMS). A total of 47 consecutive possible IPA patients who underwent bronchoscopy with BAL fluid from January 2017 to December 2018 were included. 45 people had a pair of BAL fluid specimens and 2 patients had two BAL fluid specimens. The 49 pairs of BAL fluid specimens were processed for culture, tuberculosis acid fast staining smear, direct microbial smear, and LCT with special staining (PAS and GMS), respectively. Then, we compared the sensitivity and specificity of PAS and GMS in BAL fluid in high-risk patients. Among 47 possible IPA patients, 25 patients had proven/probable IPA, and 11 patients had other invasive fungal diseases. The sensitivity of GMS was higher than that of PAS (92.11% versus 81.58%; P = 0.175). The specificity of GMS was 81.82%, which was higher than that of PAS (81.82% versus 72.73%; P = 0.611). The negative predictive value (NPV) for PAS and GMS were 53.33% and 75.00%, respectively. The positive predictive value (PPV) for PAS and GMS were 91.18% and 94.59%, respectively. This study showed that special staining of LCT in BAL fluid may be a novel method for the diagnosis of IPA, and the GMS of LCT had higher sensitivity and specificity, which was superior to PAS.

Opportunistic infections in pediatrics: when to suspect and how to approach

OBJECTIVES

To describe the characteristics of opportunistic infections in pediatrics regarding their clinical aspects, as well as the diagnostic strategy and treatment.

SOURCE OF DATA

Non-systematic review of literature studies in the PubMed database.

SYNTHESIS OF DATA

Opportunistic infections caused by non-tuberculous mycobacteria, fungi, Herpesvirae, and infections affecting individuals using immunobiological agents are analyzed. Because these are severe diseases with a rapid evolution, diagnostic suspicion should be early, associated with the patient's clinical assessment and history pointing to opportunistic infections. Whenever possible, samples of secretions, blood, and other fluids and tissues should be collected, with early therapy implementation.

CONCLUSIONS

Despite the improved diagnosis of opportunistic infections in recent years, they remain a challenge for pediatricians who are not used to these infections. They should raise the suspicion and start treating the case, but should also resort to specialists in the management of these infections to provide a better outcome for these patients, who still have high mortality.

Molecular Diagnostics of Mucormycosis in Hematological Patients: A Literature Review

OBJECTIVES

to analyze the results of molecular methods applying for the diagnosis of mucormycosis in hematologic patients based on a literature review.

DATA SOURCES

A systematic search in databases PubMed, Google Scholar for August 2019. Review eligibility criteria: original articles published in English, studies of molecular methods for the diagnosis of mucormycosis in hematologic patients.

RESULTS

We analyzed the research data from 116 hematological patients with mucormycosis, including children (6%). Patients with localized forms of mucormycosis prevailed (72%), and lung involvement was diagnosed in 58% of these cases. For molecular verification of the causative agent of mucormycosis, blood serum was most often used, less commonly postoperative and autopsy material, biopsy specimens, formalin-fixed paraffin-embedded samples and bronchoalveolar lavage, pleural fluid and sputum. The sensitivity of molecular diagnostics of mucormycosis in a cohort of hematological patients was 88.2%.

CONCLUSION

The use of molecular techniques along with standard mycological methods will improve the diagnostics of mucormycosis in hematologic patients. However, prospective studies of the effectiveness of molecular methods for the diagnosis of mucormycosis of various etiologies in hematological patients, including children, using bronchoalveolar lavage (BAL) and cerebrospinal fluid (CSF) are needed.

Evaluation of a Novel Mitochondrial Pan-Mucorales Marker for the Detection, Identification, Quantification, and Growth Stage Determination of Mucormycetes

Mucormycosis infections are infrequent yet aggressive and serious fungal infections. Early diagnosis of mucormycosis and its discrimination from other fungal infections is required for targeted treatment and more favorable patient outcomes. The majority of the molecular assays use 18 S rDNA. In the current study, we aimed to explore the potential of the mitochondrial rnl (encoding for large-subunit-ribosomal-RNA) gene as a novel molecular marker suitable for research and diagnostics. Rnl was evaluated as a marker for: (1) the Mucorales family, (2) species identification (Rhizopus arrhizus, R. microsporus, Mucor circinelloides, and Lichtheimia species complexes), (3) growth stage, and (4) quantification. Sensitivity, specificity, discriminatory power, the limit of detection (LoD), and cross-reactivity were evaluated. Assays were tested using pure cultures, spiked clinical samples, murine organs, and human paraffin-embedded-tissue (FFPE) samples. Mitochondrial markers were found to be superior to nuclear markers for degraded samples. Rnl outperformed the UMD universal® (Molyzm) marker in FFPE (71.5% positive samples versus 50%). Spiked blood samples highlighted the potential of rnl as a pan-Mucorales screening test. Fungal burden was reproducibly quantified in murine organs using standard curves. Identification of pure cultures gave a perfect (100%) correlation with the detected internal transcribed spacer (ITS) sequence. In conclusion, mitochondrial genes, such as rnl, provide an alternative to the nuclear 18 S rDNA genes and deserve further evaluation.