Central nervous system candidiasis beyond neonates: Lessons from a nationwide study

Case report: Successful combination therapy with isavuconazole and amphotericin B in treatment of disseminated Candida tropicalis infection

Disseminated candidiasis is a severe complication in patients with hematological malignancies who have undergone chemotherapy or hematopoietic stem cell transplantation. It has a high mortality rate. When disseminated candidiasis caused by Candida tropicalis involves either the brain or heart, the prognosis is extremely poor. Traditional methods such as cultures are limited in diagnosing disseminated candidiasis. We describe a case report of a 55-year-old man with acute myeloid leukemia who developed candidemia caused by Candida tropicalis after chemotherapy, which disseminated extensively to the heart, brain, skin, liver, spleen and kidneys. In this instance, the patient was rapidly diagnosed with candida infection by metagenomic next generation sequencing, and successfully treated with combination therapy of isavuconazole and amphotericin B. The patient continued with treatment of leukemia while simultaneously receiving antifungal therapy, and both leukemia and disseminated candidiasis were effectively controlled. This case report provides real-world experience for treatment of patients with leukemia complicated by disseminated candidiasis.

Longitudinally extensive posterolateral myelitis revealing invasive CNS aspergillosis in an immunocompetent patient

BACKGROUND

Fungal infections of the central nervous system usually affect immunocompromised patients. Primary Aspergillus myelitis has never been described.

REPORT

A 45-year-old immunocompetent male with subacute paraplegia was treated for inflammatory myelitis before clinical deterioration requiring mechanical ventilation. Purulent meningitis preceded the formation of a paraspinal nodule biopsied by neurosurgery. Histopathological analysis revealed the presence of fungal hyphae, and polymerase chain reaction was positive for Aspergillus fumigatus. No cause of immunodeficiency was identified in this patient.

DISCUSSION

Primary Aspergillus myelitis may be confused with inflammatory myelitis and should be considered even in the absence of apparent immunosuppression.

Case report: Chronic Candida albicans meningitis: a rare entity diagnosed by metagenomic next-generation sequencing

The aetiology of chronic aseptic meningitis is difficult to establish. Candida meningitis in particular is often diagnosed late, as cerebrospinal fluid (CSF) work-up and imaging findings are nonspecific. A 35-year-old patient with chronic aseptic meningitis, for which repeated microbiological testing of CSF was unrevealing, was finally diagnosed with Candida albicans (C. albicans) meningitis with cauda equina involvement using metagenomic next-generation sequencing (mNGS). This report highlights the diagnostic challenges and the difficulties of treating shunt-associated fungal meningitis.

Infectious Myelopathies

OBJECTIVE

Infectious myelopathy of any stage and etiology carries the potential for significant morbidity and mortality. This article details the clinical presentation, risk factors, and key diagnostic components of infectious myelopathies with the goal of improving the recognition of these disorders and guiding subsequent management.

LATEST DEVELOPMENTS

Despite our era of advanced multimodal imaging and laboratory diagnostic technology, a causative organism often remains unidentified in suspected infectious and parainfectious myelopathy cases. To improve diagnostic capability, newer technologies such as metagenomics are being harnessed to develop diagnostic assays with a greater breadth of data from each specimen and improvements in infection identification. Conventional assays have been optimized for improved sensitivity and specificity.

ESSENTIAL POINTS

Prompt recognition and treatment of infectious myelopathy decreases morbidity and mortality. The key diagnostic tools include serologies, CSF analysis, and imaging; however clinical presentation, epidemiologic risk factors, and history of recent illness are all vital to making the proper diagnosis because current laboratory and imaging modalities are often inconclusive. The cornerstone of recommended treatment is targeted antimicrobials with appropriate immune modulation, surgical intervention, supportive care, and interdisciplinary involvement, all of which further improve outcomes for patients with infectious myelopathy.

ß-D-Glucan Assay in the Cerebrospinal Fluid for the Diagnosis of Non-cryptococcal Fungal Infection of the Central Nervous System: A Retrospective Multicentric Analysis and a Comprehensive Review of the Literature

BACKGROUND

Except for cryptococcosis, fungal infection of the central nervous system (FI-CNS) is a rare but severe complication. Clinical and radiological signs are non-specific, and the value of conventional mycological diagnosis is very low. This study aimed to assess the value of β1,3-D-glucan (BDG) detection in the cerebrospinal fluid (CSF) of non-neonatal non-cryptococcosis patients.

METHODS

Cases associated with BDG assay in the CSF performed in 3 French University Hospitals over 5 years were included. Clinical, radiological, and mycological results were used to classify the episodes as proven/highly probable, probable, excluded, and unclassified FI-CNS. Sensitivity and specificity were compared to that calculated from an exhaustive review of the literature.

RESULTS

In total, 228 episodes consisting of 4, 7, 177, and 40 proven/highly probable, probable, excluded, and unclassified FI-CNS, respectively, were analysed. The sensitivity of BDG assay in CSF to diagnose proven/highly probable/probable FI-CNS ranged from 72.7% [95% confidence interval {CI}: 43.4%‒90.2%] to 100% [95% CI: 51%‒100%] in our study and was 82% in the literature. For the first time, specificity could be calculated over a large panel of pertinent controls and was found at 81.8% [95% CI: 75.3%‒86.8%]. Bacterial neurologic infections were associated with several false positive results.

CONCLUSIONS

Despite its sub-optimal performance, BDG assay in the CSF should be added to the diagnostic armamentarium for FI-CNS.

Invasive candidiasis: current clinical challenges and unmet needs in adult populations

Invasive candidiasis (IC) is a serious infection caused by several Candida species, and the most common fungal disease in hospitals in high-income countries. Despite overall improvements in health systems and ICU care in the last few decades, as well as the development of different antifungals and microbiological techniques, mortality rates in IC have not substantially improved. The aim of this review is to summarize the main issues underlying the management of adults affected by IC, focusing on specific forms of the infection: IC developed by ICU patients, IC observed in haematological patients, breakthrough candidaemia, sanctuary site candidiasis, intra-abdominal infections and other challenging infections. Several key challenges need to be tackled to improve the clinical management and outcomes of IC patients. These include the lack of global epidemiological data for IC, the limitations of the diagnostic tests and risk scoring tools currently available, the absence of standardized effectiveness outcomes and long-term data for IC, the timing for the initiation of antifungal therapy and the limited recommendations on the optimal step-down therapy from echinocandins to azoles or the total duration of therapy. The availability of new compounds may overcome some of the challenges identified and increase the existing options for management of chronic Candida infections and ambulant patient treatments. However, early identification of patients that require antifungal therapy and treatment of sanctuary site infections remain a challenge and will require further innovations.

Serologic biomarkers in Candida and Aspergillus infections of the central nervous system: a comparison of galactomannan, mannan, and β-1,3-D-gucan testing from serum and cerebrospinal fluid

BACKGROUND

The incidence of Aspergillus and Candida CNS infection, which are characterized by high mortality rates, is underestimated. This underdiagnosis presumably results from the limitations of available diagnostic tools and the need for invasive sampling. Little is known about the role of serologic biomarkers in the setting of CNS aspergillosis and candidiasis.

PATIENTS, MATERIALS, METHODS

Serum (19) and cerebrospinal fluid (CSF; 10) samples of 19 patients, whose CNS specimens yielded growth of Aspergillus or Candida, were analyzed for different biomarkers for fungal infection, i.e., galactomannan (GM), galactomannoprotein (GP), mannan, anti-mannan-antibodies, and β-1,3-D-glucan (BDG). Serum and CSF specimens of time-matched patients (two each for every case of fungal CNS infection) were included as controls.

RESULTS

GM, GP, and BDG seropositivity was found in one, two, and three of five cases of CNS aspergillosis. BDG and mannan / anti-mannan-antibody sensitivity in proven CNS candidiasis was 40 % and 20 %, respectively. Applying the serum cut off, sensitivity in CSF testing was 100 % for GM and BDG, and 50 % for mannans. While serum specificity for all assays ranged from 89 - 97 %, specificity for CSF BDG was only 70 %. No false positive GM results from CSF were obtained.

CONCLUSION

Sensitivity for diagnosing CNS aspergillosis and CNS candidiasis from serum is mediocre for all serological biomarkers. GM testing in CSF proved excellent performance. With a sensitivity of 100 % but a specificity of only 70 %, CSF BDG might be most useful when used in patients with a high pre-test probability.

Single and Repeated Episodes of Candida Species Isolated From Cerebrospinal Fluid for Diagnosing Probable Candida meningitis

Background: The clinical relevance of single or repeated episodes of Candida spp. in cerebrospinal fluid (CSF) in adult patients is debatable.

Methods: Forty-two patients with positive Candida episodes in CSF were enrolled in this retrospective study.

Results: A total of 42.9% (18/42) were determined to have probable Candida meningitis (PCM). Neurosurgery [odds ratio (OR) (95% confidence interval), OR: 14.4 (1.6–126.1), P = 0.004], lumbar drainage [OR: 5.8 (1.5–23.3), P = 0.009], VP shunt [(OR: 5.6 (1.2–25.8), P = 0.020)], external ventricular drainage [OR: 4.7 (1.3–17.7), P = 0.018], CRP ≥ 10.0 mg/L [OR: 4.9 (1.3–18.1), P = 0.034], and postsurgical broad-spectrum antibiotics [OR: 9.5 (1.8–50.5), P = 0.004] were risk factors associated with PCM. A single CSF Candida episode for the diagnosis of PCM had 7.7% (0.4–37.9%) sensitivity and 20.7% (8.7–40.3%) specificity, whereas repeated episodes of Candida had 66.7% (41.2–85.6%) sensitivity and 95.8% (76.9–99.8%) specificity. No significant difference was found in radiological imaging or CSF profiles between PCM and non-PCM patients. A total of 37.5% (9/24) of patients without PCM received empirical antifungal treatment, and 88.9% (16/18) of patients with PCM received preemptive antifungal treatment. PCM patients had hospitalized mortality rates of 50.0% (9/18). The odds ratio of mortality was 23.0 (2.5–208.6) for PCM patients compared with non-PCM patients (P = 0.001).

Conclusion: Both single and repeated positive CSF samples have low validity for the diagnosis of PCM, suggesting that novel strategies for diagnosis algorithms of PCM are urgently needed. Empirical antifungal treatment should be started immediately for suspicious patients with risk factors.

Comparative effectiveness of amphotericin B, azoles and echinocandins in the treatment of candidemia and invasive candidiasis: A systematic review and network meta-analysis

BACKGROUND + OBJECTIVES: The echinocandins, amphotericin B preparations, voriconazole and fluconazole are approved for the treatment of invasive candidiasis, though it remains unclear which agent is most effective. In order to answer this question, we performed a systematic review and network meta-analysis of the randomised controlled trials (RCTs) which evaluated these agents in comparison.

METHODS

Four electronic databases were searched from database inception to 8 October 2020. RCTs comparing triazoles, echinocandins or amphotericin B for the treatment of invasive candidiasis or candidemia were included. Random effect Bayesian network meta-analysis methods were used to compare treatment outcomes.

RESULTS

Thirteen RCTs met inclusion criteria. Of the 3528 patients included from these trials, 1531 were randomised to receive an echinocandin, 944 to amphotericin B and 1053 to a triazole. For all forms of invasive candidiasis, echinocandins were associated with the highest rate of treatment success when compared to amphotericin B (OR 1.41, 95% CI 1.04-1.92) and the triazoles (OR 1.82, 95% CI 1.35-2.51). Rank probability analysis favoured echinocandins as the most effective choice 98% of the time. Overall survival did not significantly differ between groups.

CONCLUSIONS

Among patients with invasive candidiasis, echinocandins had the best clinical outcomes and should remain the first-line agents in the treatment of invasive candidiasis.