Fatal meningoencephalitis caused by Scedosporium inflatum (Scedosporium prolificans) in a child with lymphoblastic leukemia

Lomentospora prolificans: An Emerging Opportunistic Fungal Pathogen

Lomentospora prolificans is an emerging opportunistic pathogen that primarily affects immunocompromised individuals leading to disseminated disease with high mortality rates while also causing infections in healthy populations. Successful recovery from infection is difficult due to high rates of intrinsic resistance to antifungals. Rapid and readily available diagnostic methods, aggressive surgical debridement wherever appropriate, and effective and timely antifungal treatment are the pillars for successful management. Future research will need to clarify the environmental niche of the fungus, further investigate the pathophysiology of infection and define species-specific therapeutic targets.

Invasive Scedosporium spp. and Lomentospora prolificans infections in pediatric patients: Analysis of 55 cases from FungiScope® and the literature

OBJECTIVES

Current knowledge on infections caused by Scedosporium spp. and Lomentospora prolificans in children is scarce. We therefore aim to provide an overview of risk groups, clinical manifestation and treatment strategies of these infections.

METHODS

Pediatric patients (age ≤18 years) with proven/probable Scedosporium spp. or L. prolificans infection were identified in PubMed and the FungiScope® registry. Data on diagnosis, treatment and outcome were collected.

RESULTS

Fifty-five children (median age 9 years [IQR: 5-14]) with invasive Scedosporium spp. (n = 33) or L. prolificans (n = 22) infection were identified between 1990 and 2019. Malignancy, trauma and near drowning were the most common risk factors. Infections were frequently disseminated. Most patients received systemic antifungal therapy, mainly voriconazole and amphotericin B, plus surgical treatment. Overall, day 42 mortality was 31%, higher for L. prolificans (50%) compared to Scedosporium spp. (18%). L. prolificans infection was associated with a shorter median survival time compared to Scedosporium spp. (6 days [IQR: 3-28] versus 61 days [IQR: 16-148]). Treatment for malignancy and severe disseminated infection were associated with particularly poor outcome (HR 8.33 [95% CI 1.35-51.40] and HR 6.12 [95% CI 1.52-24.66], respectively). Voriconazole use at any time and surgery for antifungal treatment were associated with improved clinical outcome (HR 0.33 [95% CI 0.11-0.99] and HR 0.09 [95% CI 0.02-0.40], respectively).

CONCLUSIONS

Scedosporium spp. and L. prolificans infections in children are associated with high mortality despite comprehensive antifungal therapy. Voriconazole usage and surgical intervention are associated with successful outcome.

Practical Diagnostic Approach to the Presence of Hyphae in Neuropathology Specimens With Three Illustrative Cases

OBJECTIVES

Early and accurate diagnosis remains crucial in the therapeutic management of invasive central nervous system fungal infections. Different molds have intrinsic resistance to antifungal agents; thus, morphologic differentiation is helpful to clinicians.

METHODS

Using three examples, we present a guide on how to approach neuropathology specimens where hyphae are identified on initial histologic examination.

RESULTS

Hyphae can be classified into three basic groups: hyaline pauciseptated, hyaline septated, and pigmented or dematiaceous. The hyaline pauciseptated group includes the order of the Mucorales (previously Zygomyces) and is frequent in patients with decompensated diabetes and severe neutropenia. Aspergillus species constitutes the most frequently isolated mold in the hyaline septated group. However, other invasive hyaline septated molds include Fusarium species, which is frequently resistant to multiple antifungals, and Candida species Last, dematiaceous molds, although infrequent, can be found in neuropathology specimens, as happened during the outbreak of Exserohilum associated with manufacturing practices in a compound pharmacy.

CONCLUSIONS

Categorizing hyphae into the three groups described allows pathologists to provide information that is useful for infectious disease treatment with an inclusive differential diagnosis of diverse fungal genera that share the same morphological features.

Central Nervous System Fungal Infection and Acute Lymphoblastic Leukemia in Children: What is the Optimal Duration of Antifungal Therapy?

Invasive fungal infections are rare in children with acute lymphoblastic leukemia. It compromises the antileukemia therapy should it happen. Central nervous system fungal infections carry high mortality. We here report the case of a 6.5-year-old girl who developed multiple central nervous system fungal abscesses possibly due to Aspergillus infection during induction therapy for acute lymphoblastic leukemia who has been successfully managed without compromising antileukemia therapy. She has been receiving antifungal therapy and maintenance chemotherapy for 20 months from diagnosis. We reviewed literature about the optimal duration of therapy for such children as the reported cases duration ranged between 4 and 24 months.

ESCMID and ECMM joint guidelines on diagnosis and management of hyalohyphomycosis: Fusarium spp., Scedosporium spp. and others

Mycoses summarized in the hyalohyphomycosis group are heterogeneous, defined by the presence of hyaline (non-dematiaceous) hyphae. The number of organisms implicated in hyalohyphomycosis is increasing and the most clinically important species belong to the genera Fusarium, Scedosporium, Acremonium, Scopulariopsis, Purpureocillium and Paecilomyces. Severely immunocompromised patients are particularly vulnerable to infection, and clinical manifestations range from colonization to chronic localized lesions to acute invasive and/or disseminated diseases. Diagnosis usually requires isolation and identification of the infecting pathogen. A poor prognosis is associated with fusariosis and early therapy of localized disease is important to prevent progression to a more aggressive or disseminated infection. Therapy should include voriconazole and surgical debridement where possible or posaconazole as salvage treatment. Voriconazole represents the first-line treatment of infections due to members of the genus Scedosporium. For Acremonium spp., Scopulariopsis spp., Purpureocillium spp. and Paecilomyces spp. the optimal antifungal treatment has not been established. Management usually consists of surgery and antifungal treatment, depending on the clinical presentation.

Melanized fungi in human disease

Melanized or dematiaceous fungi are associated with a wide variety of infectious syndromes, including chromoblastomycosis, mycetoma, and phaeohyphomycosis. [corrected]. Many are soil organisms and are generally distributed worldwide, though certain species appear to have restricted geographic ranges. Though they are uncommon causes of disease, melanized fungi have been increasingly recognized as important pathogens, with most reports occurring in the past 20 years. The spectrum of diseases with which they are associated has also broadened and includes allergic disease, superficial and deep local infections, pneumonia, brain abscess, and disseminated infection. For some infections in immunocompetent individuals, such as allergic fungal sinusitis and brain abscess, they are among the most common etiologic fungi. Melanin is a likely virulence factor for these fungi. Diagnosis relies on careful microscopic and pathological examination, as well as clinical assessment of the patient, as these fungi are often considered contaminants. Therapy varies depending upon the clinical syndrome. Local infection may be cured with excision alone, while systemic disease is often refractory to therapy. Triazoles such as voriconazole, posaconazole, and itraconazole have the most consistent in vitro activity. Further studies are needed to better understand the pathogenesis and optimal treatment of these uncommon infections.

Infections caused by Scedosporium spp

Scedosporium spp. are increasingly recognized as causes of resistant life-threatening infections in immunocompromised patients. Scedosporium spp. also cause a wide spectrum of conditions, including mycetoma, saprobic involvement and colonization of the airways, sinopulmonary infections, extrapulmonary localized infections, and disseminated infections. Invasive scedosporium infections are also associated with central nervous infection following near-drowning accidents. The most common sites of infection are the lungs, sinuses, bones, joints, eyes, and brain. Scedosporium apiospermum and Scedosporium prolificans are the two principal medically important species of this genus. Pseudallescheria boydii, the teleomorph of S. apiospermum, is recognized by the presence of cleistothecia. Recent advances in molecular taxonomy have advanced the understanding of the genus Scedosporium and have demonstrated a wider range of species than heretofore recognized. Studies of the pathogenesis of and immune response to Scedosporium spp. underscore the importance of innate host defenses in protection against these organisms. Microbiological diagnosis of Scedosporium spp. currently depends upon culture and morphological characterization. Molecular tools for clinical microbiological detection of Scedosporium spp. are currently investigational. Infections caused by S. apiospermum and P. boydii in patients and animals may respond to antifungal triazoles. By comparison, infections caused by S. prolificans seldom respond to medical therapy alone. Surgery and reversal of immunosuppression may be the only effective therapeutic options for infections caused by S. prolificans.

Infections Due to Scedosporium apiospermum and Scedosporium prolificans in Transplant Recipients: Clinical Characteristics and Impact of Antifungal Agent Therapy on Outcome

BACKGROUND

Unique characteristics, impact of therapy with antifungal agents, and outcome of infections with Scedosporium species were assessed in transplant recipients.

METHODS

The patients comprised a total of 80 transplant recipients with Scedosporium infections, including 13 patients from our institutions (University of Pittsburgh Medical Center [Pittsburgh, PA], University of Maryland [Baltimore], Duke University Medical Center [Durham, NC], Emory University [Atlanta, GA], and Hospital Gregorio Maranon [Madrid, Spain]) and 67 reported in the literature. The transplant recipients were compared with 190 non-transplant recipients with scedosporiosis who were described in the literature.

RESULTS

Overall, 69% of the infections in hematopoietic stem cell transplant (HSCT) recipients and 53% of the infections in organ transplant recipients were disseminated. HSCT recipients, compared with organ transplant recipients, were more likely to have infections caused by Scedosporium prolificans (P=.045), to have an earlier onset of infection (P=.007), to be neutropenic (P<.0001), and to have fungemia (P=.04). Time elapsed from transplantation to Scedosporium infection in transplant recipients has increased in recent years (P=.002). The mortality rate among transplant recipients with scedosporiosis was 58%. In a logistic regression model using amphotericin B as comparison treatment, voriconazole was associated with a trend towards better survival (odds ratio [OR], 10.40; P=.08). Presence of disseminated infection (OR, 0.20; P=.03) predicted lower survival, and receipt of adjunctive surgery as treatment (OR, 5.52; P=.02) independently predicted a better survival in this model.

CONCLUSIONS

Scedosporium infections in transplant recipients were associated with a high rate of dissemination and a poor outcome overall. The use of newer triazole agents warrants consideration as a therapeutic modality for these infections.

Primary Central Nervous System Phaeohyphomycosis: A Review of 101 Cases

Phaeohyphomycosis refers to infections caused by darkly pigmented fungi. These fungi rarely cause life-threatening disease. We reviewed 101 cases of culture-proven primary central nervous system phaeohyphomycosis reported in the English-language literature from 1966 to 2002. The most frequently isolated species was Cladophialophora bantiana. The next most frequent isolate was Ramichloridium mackenziei, seen exclusively in patients from the Middle East. More than one-half of the cases occurred in patients with no known underlying immunodeficiency. Mortality rates were high regardless of immune status. Therapy is not standardized, although the combination of amphotericin B, flucytosine, and itraconazole may improve survival rates. Newer azoles, such as voriconazole, also have a broad spectrum of activity against these fungi, although clinical experience is limited. Complete excision of brain lesions may provide better results than simple aspiration. An aggressive medical and surgical approach is warranted in treating these infections to optimize outcomes.

Central nervous system aspergillosis: a 20-year retrospective series

Over the past 20 years at my institution, 71 patients with invasive necrotizing aspergillosis have been encountered; 42 have shown central nervous system (CNS) involvement by autopsy (40) or surgical biopsy (2). Most non-CNS aspergillosis patients had invasive disease confined to the lung, and only 2 with dissemination to 3 or more organs did not have spread to the CNS. In addition to the expected post-transplantation and hematologic malignancy cases, other risk groups identified included those with chronic asthma and steroid use, acquired immunodeficiency syndrome, thermal burn, hepatic failure, and postoperative infection. Unusual cases manifested with basilar meningitis, myelitis, proptosis caused by sino-orbital disease, or epidural and subdural Aspergillus abscesses. The extent of gross neuropathologic disease ranged from subtle abscesses to massive hemorrhagic necrosis causing herniation and death. In addition to the expected hemorrhagic necrosis, extensive hemorrhage, focal purulent meningitis, and subtle bland infarctions were also seen. Distinctive microscopic findings encountered included 1 case with numerous meningeal granulomas and multinucleated giant cells and 4 cases showing the Splendore-Hoeppli phenomenon. During the same period, single cases of cerebritis caused by morphologically similar fungi (Pseudoallescheria boydii [Scedosporium apiospermum], Scedosporium inflatum, Chaetomium sp) were identified and were indistinguishable from CNS aspergillosis clinically and pathologically.

[Infection and colonization by Scedosporium prolificans]

BACKGROUND

Scedosporium prolificans is a dematiaceous fungus that is known to cause a wide spectrum of infections in humans, bearing a severity and a prognosis that is relationed with the patients immune status.

METHODS

A retrospective review was made of the clinical charts of all patients who developed positive S. prolificans cultures in our centre from 1990 to 2000. Isolates were identified by colonial morphology and microscopic features. The in vitro susceptibility was evaluated using the microdilution method according to NCCLS.

RESULTS

S. prolificans was isolated in 15 patients. Eight were affected with cystic fibrosis and the isolation of S. prolificans in their airways did not worsen their clinical status. Among the remaining 7 cases there were five leukemic patients with neutropenia and two immunocompetent hosts with cutaneous infection and endocarditis. Four of five neutropenic patients died of sudden sepsis and S. prolificans was isolated from blood cultures made a few days before their death, and the fifth neutropenic case suffered a bilateral pneumonia with improving course probably due to recovery from neutropenia. As to the immunocompetent group the clinical course was good in the cutaneous infection case, but the endocarditis case died four days after the antifungical therapy was started. All the isolates tested were found to be resistant to amphotericin, 5 flucytosine, fluconazole, itraconazole, voriconazole, miconazole and terbinafine.

CONCLUSIONS

Scedosporium prolificans is a fungal pathogen that colonizes the airways of patients affected with cystic fibrosis. It can also cause a wide variety of infections, whose severity and prognosis depends on the patients immune status. Due to the resistance of this fungus to antifungal drugs, the therapeutic options are limited. Only with the correction of neutropenia and surgery in local infections in immunocompetent hosts it has been possible to cure these infections.

Disseminated infection and colonization by Scedosporium prolificans: a review of 18 cases, 1990-1999

Scedosporium prolificans infection was analyzed in 18 patients from whom the fungus was isolated during the period 1990-1999. Of these 18 patients, 12 had some predisposing factor and either unconfirmed infection or colonization, and 6 patients had confirmed disseminated infection: 4 patients with leukemia died, 1 patient with breast cancer who underwent autologous bone marrow transplantation survived, and 1 patient with advanced acquired immunodeficiency syndrome died, although the fungal infection did not seem to affect his clinical symptoms.

Occurrence of itraconazole-tolerant micromycetes in the soil and food products

Unexpected pathogens from the environment represent considerable risk for humans with impaired health. We examined the occurrence of itraconazole tolerant micromycetes in soil and in maize products. Five concentrations of itraconazole (2.5-12.5 micrograms/mL) selected according to known treatment schedules for human patients were incorporated into Sabouraud agar with chloramphenicol and Rose Bengal and diluted samples were inoculated onto the agar surface. After 7-d growth at 22 degrees C colonies of Alternaria sp., Aspergillus clavatus, A. glaucus group, A. flavus, A. fumigatus, A. niger group, A. ochraceus group, A. ochraceus, Chaetomium sp., Cladosporium cladosporioides, Cylindrocarpon sp., Doratomyces sp., Fusarium sp., F. moniliforme, F. oxysporum, F. solani, F. subglutinans, Marianaea elegans, Mortierella sp., Mucor sp., Myrothecium sp., Penicillium sp., Rhizopus sp., Scopulariopsis brevicaulis, Sepedonium sp., Stachybotrys chartarum, Stemphylium sp., Torula humicola and Trichoderma viride were isolated.

Disseminated infection caused by Scedosporium prolificans in a patient with acute multilineal leukemia

In this report, we describe a case of disseminated infection caused by Scedosporium prolificans (S. inflatum) in a patient affected by chemotherapy-induced acute multilineal leukemia and neutropenia. For the fungus isolated in four blood cultures, high MICs of currently available antifungal agents were found. Postmortem examination revealed multiorgan involvement.

[Nosocomial infections due to opportunistic fungi: analysis of a news outbreak in the Spanish press]

BACKGROUND

To study an outbreak of media news related to nosocomial infections due to opportunistic fungi in Spanish hospitals.

METHOD

CASE DEFINITION

any news related to possible nosocomial infection due to opportunistic fungi in Spanish hospitals, published in national or local daily newspapers, over the pre-epidemic (July-December, 1998) and epidemic periods (January-June, 1999). All news were reviewed and identified using global press reports summaries, prepared by two independent sources, and were analyzed by three different observers.

RESULTS

Over the pre-epidemic period there were not any news related to nosocomial infections due to opportunistic fungi. Over the epidemic period, a total of 218 news were identified, 154 (71%) published in national newspapers and 64 (29%) in local ones. We analyzed separately 18 editorials or opinion articles related to this subject. The epidemic curve (distribution of news by week) showed an incidence news peak at week 5 (102 news, 46.7% of all news published). The media mentioned up to 19 different hospitals as institutions with possible cases of nosocomial fungal infections. After week 8, news incidence drop, and remain thereafter at minimum levels.

CONCLUSIONS

The example provided by the analysis of this outbreak of media news, related to nosocomial infections by Aspergillus an other opportunistic fungi, is useful to allow us understand how some medical news arise, develop and were transmitted. The public alert situation created in Spain was remarkable, and it is likely that there was a transient loss of confidence in the safety of public health institutions. Today's medicine requires a great and better openness to the media, and a better cooperation between both parts.

Fatal Scedosporium prolificans infection in a leukemic patient

The case is described of a 42-year-old patient with acute myeloid leukemia who received two courses of chemotherapy complicated by prolonged bone marrow depression. He was admitted to hospital with fever, hepatosplenomegaly and bilateral nodular pulmonary infiltrates. After admission diffuse cutaneous skin nodules, and hypodense lesions in the hemispheres and cerebellum developed. Cultures of cerebrospinal fluid, bronchoalveolar lavage fluid, skin biopsy specimens and blood revealed Scedosporium prolificans, indicative of disseminated mycosis. Treatment with amphotericin B and fluconazole was unsuccessful and the patient died within five days after admission. Features that may enhance early recognition of Scedosporium prolificans infection by both clinicians and microbiologists, as well as options in the treatment of infection with this fungal agent are discussed.

Disseminated mycosis due to Scedosporium prolificans in an AIDS patient with Burkitt lymphoma

A case of fatal disseminated infection caused by the dematiaceous hyphomycete Scedosporium prolificans diagnosed post mortem is reported in a 60-year-old male patient with acquired immunodeficiency syndrome who additionally suffered from Burkitt's lymphoma. The patient was significantly granulocytopenic following aggressive chemotherapy and irradiation. He developed dyspnoea at rest and chest pain despite a normal chest radiograph. Fluconazole treatment was carried out empirically because no sign of a fungal infection was detected ante mortem, either by mycological cultivation or by serological investigation. First post-mortem examination revealed a disseminated fungal infection involving the central nervous system. Scedosporium prolificans was cultured from the kidney, spleen and myocardium. In vitro, the fungal isolate was found to be highly resistant to all available systemic antimycotics.