Fatal mycotic aneurysms due to Scedosporium and Pseudallescheria infection

Scedosporiosis and lomentosporiosis: modern perspectives on these difficult-to-treat rare mold infections

SUMMARYAlthough Scedosporium species and Lomentospora prolificans are uncommon causes of invasive fungal diseases (IFDs), these infections are associated with high mortality and are costly to treat with a limited armamentarium of antifungal drugs. In light of recent advances, including in the area of new antifungals, the present review provides a timely and updated overview of these IFDs, with a focus on the taxonomy, clinical epidemiology, pathogenesis and host immune response, disease manifestations, diagnosis, antifungal susceptibility, and treatment. An expansion of hosts at risk for these difficult-to-treat infections has emerged over the last two decades given the increased use of, and broader population treated with, immunomodulatory and targeted molecular agents as well as wider adoption of antifungal prophylaxis. Clinical presentations differ not only between genera but also across the different Scedosporium species. L. prolificans is intrinsically resistant to most currently available antifungal agents, and the prognosis of immunocompromised patients with lomentosporiosis is poor. Development of, and improved access to, diagnostic modalities for early detection of these rare mold infections is paramount for timely targeted antifungal therapy and surgery if indicated. New antifungal agents (e.g., olorofim, fosmanogepix) with novel mechanisms of action and less cross-resistance to existing classes, availability of formulations for oral administration, and fewer drug-drug interactions are now in late-stage clinical trials, and soon, could extend options to treat scedosporiosis/lomentosporiosis. Much work remains to increase our understanding of these infections, especially in the pediatric setting. Knowledge gaps for future research are highlighted in the review.

Deciphering Unexpected Vascular Locations of Scedosporium spp. and Lomentospora prolificans Fungal Infections, France

Scedosporium spp. and Lomentospora prolificans are emerging non-Aspergillus filamentous fungi. The Scedosporiosis/lomentosporiosis Observational Study we previously conducted reported frequent fungal vascular involvement, including aortitis and peripheral arteritis. For this article, we reviewed 7 cases of Scedosporium spp. and L. prolificans arteritis from the Scedosporiosis/lomentosporiosis Observational Study and 13 cases from published literature. Underlying immunosuppression was reported in 70% (14/20) of case-patients, mainly those who had solid organ transplants (10/14). Osteoarticular localization of infection was observed in 50% (10/20) of cases; infections were frequently (7/10) contiguous with vascular infection sites. Scedosporium spp./Lomentospora prolificans infections were diagnosed in 9 of 20 patients ≈3 months after completing treatment for nonvascular scedosporiosis/lomentosporiosis. Aneurysms were found in 8/11 aortitis and 6/10 peripheral arteritis cases. Invasive fungal disease--related deaths were high (12/18 [67%]). The vascular tropism of Scedosporium spp. and L. prolificans indicates vascular imaging, such as computed tomography angiography, is needed to manage infections, especially for osteoarticular locations.

Osteoarticular Mycoses

Osteoarticular mycoses are chronic debilitating infections that require extended courses of antifungal therapy and may warrant expert surgical intervention. As there has been no comprehensive review of these diseases, the International Consortium for Osteoarticular Mycoses prepared a definitive treatise for this important class of infections. Among the etiologies of osteoarticular mycoses are Candida spp., Aspergillus spp., Mucorales, dematiaceous fungi, non-Aspergillus hyaline molds, and endemic mycoses, including those caused by Histoplasma capsulatum, Blastomyces dermatitidis, and Coccidioides species. This review analyzes the history, epidemiology, pathogenesis, clinical manifestations, diagnostic approaches, inflammatory biomarkers, diagnostic imaging modalities, treatments, and outcomes of osteomyelitis and septic arthritis caused by these organisms. Candida osteomyelitis and Candida arthritis are associated with greater events of hematogenous dissemination than those of most other osteoarticular mycoses. Traumatic inoculation is more commonly associated with osteoarticular mycoses caused by Aspergillus and non-Aspergillus molds. Synovial fluid cultures are highly sensitive in the detection of Candida and Aspergillus arthritis. Relapsed infection, particularly in Candida arthritis, may develop in relation to an inadequate duration of therapy. Overall mortality reflects survival from disseminated infection and underlying host factors.

Rapid sequential development and rupture of mycotic aneurysms within a period of days in a patient with graft-versus-host disease and angiotropic Scedosporium apiospermum infection

Background:

Fungal origin mycotic aneurysms are rare and carry a high mortality rate. Scedosporium apiospermum is an ubiquitous fungus which has been described to cause devastating infections in immunocompromised hosts.

Case Description:

We report a case of a 23-year-old patient with Burkitt’s lymphoma and graft-versus-host disease admitted with intracerebral hemorrhage and sequential development of 12 anterior circulation aneurysms from disseminated Scedosporium infection. Despite aggressive surgical and antimicrobial treatment, the patient died 6 months later from multiorgan failure. The notable feature of this case is the rapid angioinvasiveness of the infection with new aneurysm formation within days of clear angiographic imaging despite the apparent lack of skull base osteomyelitis.

Conclusion:

We highlight the difficulties in treating fungal mycotic aneurysms and the associated high mortality. While a less aggressive approach might have been appropriate given the known poor outcomes, the age of the patients as well as the family wishes dictated the treatment decisions.

Aortic Mycetoma From Disseminated Cunninghamella Species Infection

Cunninghamella species are aggressive, opportunistic fungi that are becoming more commonly reported in immunocompromised patients. We present a case of disseminated Cunninghamella sp. infection after stem cell transplant for refractory multiple myeloma with formation of bilateral pleural effusions and an aortic mycetoma. PCR analysis of the patient's aortic mycetoma demonstrated a 90% match to Cunninghamella spp. This case illustrates the potential for severe opportunistic fungal infections in immunocompromised patients that can mimic other disease processes and result in an accelerated demise.

Systematic Review of Endovascular, Surgical, and Conservative Options for Infectious Intracranial Aneurysms and Cardiac Considerations

INTRODUCTION

With rising rates of intravenous drug use, Infectious Intracranial aneurysms (IIAs) are a relevant topic for investigation. We performed a systematic review to better understand current practice patterns and limits of current published literature.

METHOD

131 publications with a total of 499 patients (665 aneurysms) were included. Of the 499 patients, 83 were single case reports, and 20.5% of the total had multiple aneurysms. 35.8% of all aneurysms were ruptured. Of those reporting treatment, options included conservative antibiotic therapy (30.0%), open surgical intervention (31.1%), and endovascular occlusion (31.8%). Chronologically, publication of IIAs has increased. Usage of endovascular therapies has grown, while conservative and surgical management have declined in the literature. Overall, 56.2% of aneurysms for which conservative therapy was initiated eventually either underwent intervention or death of patient occurred.

RESULTS

The issue of cardiac valve surgery in relationship to aneurysm therapy was discussed in 20.8% (80 patients) of all 384 infectious endocarditis patients; of which 15.0% (12) underwent valve surgery before aneurysm treatment and 85.0 patients (68)% underwent valve surgery after aneurysm treatment. For 51 of the patients where valve surgery followed aneurysm management, the corresponding aneurysm treatment modality could be determined; 58.8% (30) of whom were managed endovascularly. 32.7% (26) of all cases reporting cardiac surgery details underwent cardiac surgery during their admission with the IIA.

CONCLUSIONS

Overall, increasing trend of endovascular management of IIAs is evident, and a strong temporal preference exhibited by providers to perform cardiac surgery subsequently to IIA management.

Scedosporium and Lomentospora: an updated overview of underrated opportunists

Species of Scedosporium and Lomentospora are considered as emerging opportunists, affecting immunosuppressed and otherwise debilitated patients, although classically they are known from causing trauma-associated infections in healthy individuals. Clinical manifestations range from local infection to pulmonary colonization and severe invasive disease, in which mortality rates may be over 80%. These unacceptably high rates are due to the clinical status of patients, diagnostic difficulties, and to intrinsic antifungal resistance of these fungi. In consequence, several consortia have been founded to increase research efforts on these orphan fungi. The current review presents recent findings and summarizes the most relevant points, including the Scedosporium/Lomentospora taxonomy, environmental distribution, epidemiology, pathology, virulence factors, immunology, diagnostic methods, and therapeutic strategies.

Skull base osteomyelitis secondary to Scedosporium apiospermum infection

Scedosporium apiospermum is a common environmental mold which is increasingly reported in the literature as a cause of infection, particularly in the immunocompromised patient population. We present a case of malignant otitis externa due to S apiospermum, complicated by spread of infection causing skull base osteomyelitis, internal carotid artery vasculitis and subsequent stroke. Despite the multiple complications encountered, prompt diagnosis and initiation of appropriate antifungal treatment resulted in patient survival. Multiple imaging modalities were used to aid the establishment of the diagnosis in this complex case and highlight the radiological findings associated with skull base osteomyelitis and its possible complications.

Case of femoral pseudarthrosis due to Scedosporium apiospermum in an immunocompetent patient with successful conservative treatment and review of literature

Scedosporium apiospermum is a ubiquitous filamentous fungus, commonly found in soil, sewage and polluted waters. It is rarely pathogenic but can cause a broad spectrum of clinical diseases, which can be localised or disseminate to distant organs. The disseminated form of the disease is mostly seen among immunocompromised patients. However, some rare cases of disseminated disease have been reported in immunocompetent individuals. Treatment of these infections is challenging because of their natural resistance to many antifungal agents. Here, we report the case of a 57-year-old immunocompetent patient diagnosed with femoral pseudarthrosis due to S. apiospermum, despite having no obvious clinical sign of infection. Previously, the patient had undergone four iterative femoral surgeries following a road traffic accident which occurred 20 years before. During its last surgery for pseudarthrosis, no clinical or biological signs of infection were present. Per operative samples tested positive for S. apiospermum. The patient was successfully treated with oral voriconazole during 6 months with an excellent tolerance. We also provide a review of literature on bone and joint infections due to Scedosporium spp. (S. apiospermum, Scedosporium boydii and Scedosporium aurantiacum), discussing the evolution of their management and outcome which seems to improve since the use of voriconazole.

Rapid development of a mycotic aneurysm of the intracranial artery secondary to Scedosporium apiospermum sinusitis

An 85-year-old man complained of a 2-month history of pain on the left side of his face. Brain computed tomography (CT) and magnetic resonance imaging/magnetic resonance angiography did not clearly show any intracranial abnormality and only showed fluid effusion in his left sphenoid sinus. Filamentous fungi were detected from the left sphenoid sinus specimen. The isolate was Scedosporium apiospermum. He was empirically treated with voriconazole, to which the isolate was susceptible. His consciousness decreased rapidly. Urgent 3D-CT angiography revealed an intracranial aneurysm near the left sphenoid sinus. Despite urgent coil embolization, the aneurysm ruptured, and he died.

Osteoarticular Infections Caused by Non-Aspergillus Filamentous Fungi in Adult and Pediatric Patients: A Systematic Review

Osteoarticular mycoses due to non-Aspergillus moulds are uncommon and challenging infections. A systematic literature review of non-Aspergillus osteoarticular mycoses was performed using PUBMED and EMBASE databases from 1970 to 2013. Among 145 patients were 111 adults (median age 48.5 [16-92 y]) and 34 pediatric patients (median age 7.5 [3-15 y]); 114 (79.7%) were male and 88 (61.9%) were immunocompromised. Osteomyelitis was due to direct inoculation in 54.5%. Trauma and puncture wounds were more frequent in children (73.5% vs 43.5%; P = 0.001). Prior surgery was more frequent in adults (27.7% vs 5.9%; P = 0.025). Vertebral (23.2%) and craniofacial osteomyelitis (13.1%) with neurological deficits predominated in adults. Lower limb osteomyelitis (47.7%) and knee arthritis (67.8%) were predominantly seen in children. Hyalohyphomycosis represented 64.8% of documented infections with Scedosporium apiospermum (33.1%) and Lomentospora prolificans (15.8%) as the most common causes. Combined antifungal therapy and surgery was used in 69% of cases with overall response in 85.8%. Median duration of therapy was 115 days (range 5-730). When voriconazole was used as single agent for treatment of hyalohyphomycosis and phaeohyphomycosis, an overall response rate was achieved in 94.1% of cases. Non-Aspergillus osteoarticular mycoses occur most frequently in children after injury and in adults after surgery. Accurate early diagnosis and long-course therapy (median 6 mo) with a combined medical-surgical approach may result in favorable outcome.

Aortic Arch Mycotic Aneurysm Due to Scedosporium Apiospermum Reconstructed With Homografts

A 39-year-old female, active parenteral drug user was diagnosed of spondylodiscitis. A computed tomography (CT) scan showed an extensive aortic arch aneurysm. A positron emission tomography (PET)-CT scan, showing significant aortic wall uptake of the tracer through the whole aortic arch and the D8-D9 intervertebral disc, allowed us to suspect an aortitis despite negative blood cultures. The aneurysm was resected and reconstructed with 2 aortic homografts. Cultures of specimens from the aortic wall were positive to the fungi Scedosporium apiospermum. A new PET-CT scan 4 months after surgery showed absence of tracer uptake both at the homografts site and intervertebral disc.

Invasive aspergillosis in the aortic arch with infectious Aspergillus lesions in pulmonary bullae

A patient with pulmonary bullae died of massive hemoptysis. At autopsy a hole was observed in the aortic wall. A microscopic examination indicated small Aspergillus lesions in pulmonary bullae and extensive necrotic lesions with Aspergillus hyphae in the media of the thoracic aorta. These findings led to a diagnosis of invasive aspergillosis in the aortic arch. This is a rare case in which Aspergillus invaded the aorta in a patient without hematologic neoplasms or neutropenia.

Scedosporium prolificans pericarditis and mycotic aortic aneurysm in a lung transplant recipient receiving voriconazole prophylaxis

Despite the adoption of antifungal prophylaxis, fungal infections remain a significant concern in lung transplant recipients. Indeed, some concern exists that such prophylaxis may increase the risk of infection with drug-resistant fungal organisms. Here, we describe a case of disseminated Scedosporium prolificans infection, presenting as pericarditis, which developed in a lung transplant patient receiving prophylactic voriconazole for 8 months. The epidemiology and clinical presentation of S. prolificans infections are reviewed, and controversies surrounding antifungal prophylaxis and the development of resistant infections are discussed.

Arterial reconstruction for atypical mycotic aneurysms

Our case involves a 67-year-old man with a  post lung transplantation status for idiopathic pulmonary fibrosis, who was initially referred to our institution for treatment of left hip septic arthritis due to Pseudallescheria boydii infection. One month following total hip arthroplasty, he noticed left upper thigh swelling with duplex imaging consistent with a 7-cm mid-superficial femoral artery aneurysm with popliteal vein compression and associated deep venous thrombosis. During operative resection, exploration of his contralateral saphenous vein showed inadequate conduit for use. Therefore, we proceeded with proximal and distal clamp control with intraoperative arterial shunting followed by cryoarterial reconstruction after complete aneurysm sac resection and debridement. Intraoperative arterial wall cultures remained negative for bacterial pathogens; however, final operative fungal cultures once again grew Pseudallescheria boydii. Our case highlights the complexity of adequate source control with effective arterial reconstruction in these immunosuppressed patient populations, particularly with fungal organisms that historically have poor therapeutic response to medical therapy alone.

Invasive fungal infections after renal transplantation

BACKGROUND

Invasive fungal infection (IFI) is a leading cause of infection-related mortality among kidney allograft recipients. 

OBJECTIVE

To estimate the incidence and etiology of systemic fungal infection in renal allograft recipients in Sydney transplant facility.

METHODS

471 kidney recipients, transplanted between 2000 and 2010 at the Westmead Hospital renal transplantation center, Sydney, Australia, were retrospectively surveyed.

RESULTS

IFI developed in 10 (2.1%) of 471 patients. With a mean±SD new kidney transplants per year of 42.9±13, the mean±SD incidence of IFI was 0.9±0.6 for each year of transplantation. 4 patients had received kidneys from living donors and 7 from cadavers with a mean±SD age of 50.5±14 years. The mean time to IFI was 33 months after transplantation with majority within the first 2 years. Cryptococcus neoformans was responsible for 50% of episodes (n=5) followed by Aspergillus fumigatus (n=3), and Pseudallescheria boydii (n=3); there was a single case of mucurmycosis. Lungs (n=5) followed by meninges (n=4) and skin (n=3) were the most commonly involved sites.

CONCLUSION

IFI remains a major concern in renal transplantation. A high index of suspicion is required for early diagnosis and treatment to reduce the mortality. In this regard, appropriate diagnostic tests are necessary, particularly for C. neoformans.