Exserohilum infections associated with contaminated steroid injections: a clinicopathologic review of 40 cases

Post-Discectomy Infection: A Critical Review and Suggestion of a Management Algorithm

Postoperative discitis (POD) accounts for 20% to 30% of all cases of pyogenic spondylodiscitis, while POD may be mis-or-under-diagnosed, due to the vague related symptomatology and the non-specific imaging findings. Most studies report infection rate of less than 1%, which increases with the addition of non-instrumented fusion to 2.4% to 6.2%. It remains controversial whether POD is caused by an aseptic or infectious process. Positive cultures are presented only in 42-73% of patients with Staphylococcus species being the most common invading organisms, while Staphylococcus aureus is isolated in almost 50% of cases. The onset of POD symptoms usually occurs at 2-4 weeks after an apparently uneventful operation. Back pain and muscle spasms are usually refractory to bed rest and analgesics. Magnetic Resonance Imaging (MRI) is the most sensitive and specific imaging diagnostic technique. Antimicrobial therapy depends on the results of tissue cultures, and along with bracing represents the mainstay of management. Surgical intervention is necessary in patients failing conservative treatment. For the majority of cases, extensive surgical debridement, antibiotic therapy, and orthosis immobilization are effective in eliminating the infection. According to this, we recommend an Algorithmic approach for the management of POD. Postoperative infections after spinal surgery pose a certain clinical challenge, and in most cases can be treated conservatively. Nevertheless, disability may be persistent, and surgery could be necessary. The purpose of this concise review is to describe the manifestation of post-discectomy infection, its pathogenesis and particularly a rational approach for its management.

Neurovascular Complications of Iatrogenic Fusarium solani Meningitis

A multinational outbreak of nosocomial fusarium meningitis occurred among immunocompetent patients who had undergone surgery with epidural anesthesia in Mexico. The pathogen involved had a high predilection for the brain stem and vertebrobasilar arterial system and was associated with high mortality from vessel injury. Effective treatment options remain limited; in vitro susceptibility testing of the organism suggested that it is resistant to all currently approved antifungal medications in the United States. To highlight the severe complications associated with fusarium infection acquired in this manner, we report data, clinical courses, and outcomes from 13 patients in the outbreak who presented with symptoms after a median delay of 39 days.

Mortality associated with SARS-CoV-2 in nondomestic felids

Between September and November 2021, 5 snow leopards (Panthera uncia) and 1 lion (Panthera leo) were naturally infected with severe acute respiratory coronavirus 2 (SARS-CoV-2) and developed progressive respiratory disease that resulted in death. Severe acute respiratory syndrome coronavirus 2 sequencing identified the delta variant in all cases sequenced, which was the predominant human variant at that time. The time between initial clinical signs and death ranged from 3 to 45 days. Gross lesions in all 6 cats included nasal turbinate hyperemia with purulent discharge and marked pulmonary edema. Ulcerative tracheitis and bronchitis were noted in 4 cases. Histologically, there was necrotizing and ulcerative rhinotracheitis and bronchitis with fibrinocellular exudates and fibrinosuppurative to pyogranulomatous bronchopneumonia. The 4 cats that survived longer than 8 days had fungal abscesses. Concurrent bacteria were noted in 4 cases, including those with more acute disease courses. Severe acute respiratory syndrome coronavirus 2 was detected by in situ hybridization using probes against SARS-CoV-2 spike and nucleocapsid genes and by immunohistochemistry. Viral nucleic acid and protein were variably localized to mucosal and glandular epithelial cells, pneumocytes, macrophages, and fibrinocellular debris. Based on established criteria, SARS-CoV-2 was considered a contributing cause of death in all 6 cats. While mild clinical infections are more common, these findings suggest that some SARS-CoV-2 variants may cause more severe disease and that snow leopards may be more severely affected than other felids.

Mortality associated with SARS-CoV-2 in nondomestic felids

Between September and November 2021, 5 snow leopards ( Panthera uncia) and 1 lion ( Panthera leo) were naturally infected with severe acute respiratory coronavirus 2 (SARS-CoV-2) and developed progressive respiratory disease that resulted in death. Severe acute respiratory syndrome coronavirus 2 sequencing identified the delta variant in all cases sequenced, which was the predominant human variant at that time. The time between initial clinical signs and death ranged from 3 to 45 days. Gross lesions in all 6 cats included nasal turbinate hyperemia with purulent discharge and marked pulmonary edema. Ulcerative tracheitis and bronchitis were noted in 4 cases. Histologically, there was necrotizing and ulcerative rhinotracheitis and bronchitis with fibrinocellular exudates and fibrinosuppurative to pyogranulomatous bronchopneumonia. The 4 cats that survived longer than 8 days had fungal abscesses. Concurrent bacteria were noted in 4 cases, including those with more acute disease courses. Severe acute respiratory syndrome coronavirus 2 was detected by in situ hybridization using probes against SARS-CoV-2 spike and nucleocapsid genes and by immunohistochemistry. Viral nucleic acid and protein were variably localized to mucosal and glandular epithelial cells, pneumocytes, macrophages, and fibrinocellular debris. Based on established criteria, SARS-CoV-2 was considered a contributing cause of death in all 6 cats. While mild clinical infections are more common, these findings suggest that some SARS-CoV-2 variants may cause more severe disease and that snow leopards may be more severely affected than other felids.

Granulomatous dermatitis caused by Exserohilum mcginnisii infection in a cow

A 5-y-old, Piedmontese cow had a 4-mo history of ongoing development of skin masses. This was the only cow affected in a herd of 20 cows. Up to 12, hairless, red-to-black, raised nodules-to-plaques were distributed along the dorsum and tail head. Biopsies were taken for histopathology and ancillary testing. An ulcerated skin section contained dermal infiltrates of eosinophils, plasma cells, neutrophils, macrophages, lymphocytes, and multinucleate giant cells, and pyogranulomas. Fungal hyphae were seen within the dermis, multinucleate giant cells, and pyogranulomas. In pyogranulomas, fungi were surrounded by a Splendore-Hoeppli reaction. Dematiaceous (pigmented) hyphae were rarely observed with H&E-stained and unstained (cleared and mounted) sections, but stained well with a Fontana-Masson stain. Exserohilum mcginnisii was identified by fungal culture, followed by PCR assay and sequencing. Exserohilum is a dematiaceous fungus that causes disease in humans and rarely in animals. The use of unstained sections and Fontana-Masson stain are important to demonstrate pigment because dematiaceous fungi have little melanin and appear as hyaline hyphae histologically. PCR assay and sequencing aid in the differentiation and classification of fungal species. To our knowledge, E. mcginnisii dermal granulomas have not been reported previously in cattle.

Outbreaks of Fungal Infections in Hospitals: Epidemiology, Detection, and Management

Nosocomial clusters of fungal infections, whilst uncommon, cannot be predicted and are associated with significant morbidity and mortality. Here, we review reports of nosocomial outbreaks of invasive fungal disease to glean insight into their epidemiology, risks for infection, methods employed in outbreak detection including genomic testing to confirm the outbreak, and approaches to clinical and infection control management. Both yeasts and filamentous fungi cause outbreaks, with each having general and specific risks. The early detection and confirmation of the outbreak are essential for diagnosis, treatment of affected patients, and termination of the outbreak. Environmental sampling, including the air in mould outbreaks, for the pathogen may be indicated. The genetic analysis of epidemiologically linked isolates is strongly recommended through a sufficiently discriminatory approach such as whole genome sequencing or a method that is acceptably discriminatory for that pathogen. An analysis of both linked isolates and epidemiologically unrelated strains is required to enable genetic similarity comparisons. The management of the outbreak encompasses input from a multi-disciplinary team with epidemiological investigation and infection control measures, including screening for additional cases, patient cohorting, and strict hygiene and cleaning procedures. Automated methods for fungal infection surveillance would greatly aid earlier outbreak detection and should be a focus of research.

Molecular Techniques for Genus and Species Determination of Fungi From Fresh and Paraffin-Embedded Formalin-Fixed Tissue in the Revised EORTC/MSGERC Definitions of Invasive Fungal Infection

The EORTC/MSGERC have revised the definitions for proven, probable, and possible fungal diseases. The tissue diagnosis subcommittee was tasked with determining how and when species can be determined from tissue in the absence of culture. The subcommittee reached a consensus decision that polymerase chain reaction (PCR) from tissue, but not immunohistochemistry or in situ hybridization, can be used for genus or species determination under the new EORTC/MSGERC guidelines, but only when fungal elements are identified by histology. Fungal elements seen in tissue samples by histopathology and identified by PCR followed by sequencing should fulfill the definition of a proven fungal infection, identified to genus/species, even in the absence of culture. This summary discusses the issues that were deliberated by the subcommittee to reach the consensus decision and outlines the criteria a laboratory should follow in order to produce data that meet the EORTC/MSGERC definitions.

Performance evaluation of fungal DNA PCR amplification from formalin-fixed paraffin-embedded tissue for diagnosis: Experience of a tertiary reference laboratory

BACKGROUND

Diagnosis of invasive fungal infections from formalin-fixed paraffin-embedded (FFPE) tissues by PCR amplification is a developing technology. One of the difficulties of establishing a validated protocol for this testing is that the gold standard, culture, is much less sensitive than the test being validated.

OBJECTIVES

To validate FFPE PCR as a refence laboratory identification methodology in the absence of abundant gold standard specimens.

METHODS

In this validation, PCR from FFPE tissue was compared to other diagnostic methods for genus/species identification. Four different groups of correlative data from FFPE tissues were used to validate this procedure. Thirteen specimens had culture or serology results and FFPE PCR results, 49 specimens had both immunohistochemistry (IHC) identification and FFPE PCR results, 118 specimens had histological evidence of fungal elements, 64 of which also had FFPE PCR results, and 36 fungal mock tissues or fungal negative tissues were used.

RESULTS

The sensitivity determined from the tissues with positive fungal histopathology was 54%. The specificity of the cases for which there were both culture and FFPE PCR results was 100%. For the correlation with IHC, the specificity was 98%. For the mock tissues and fungal negative tissues, the calculated analytical sensitivity was 94%, specificity was 95%, and accuracy was 94%.

CONCLUSIONS

By uniquely combining various data sources, this study provides a comprehensive framework for how validation can be achieved in the absence of a gold standard and outlines the excellent performance of PCR from FFPE tissue, despite relatively the low sensitivity when compared to histopathology.

Long-term Outcomes of Patients With Fungal Infections Associated With Contaminated Methylprednisolone Injections

Background

The largest health care–associated infection outbreak in the United States occurred during 2012–2013. Following injection of contaminated methylprednisolone, 753 patients developed infection with a dematiaceous mold, Exserohilum rostratum. The long-term outcomes of these infections have not been described.

Methods

This retrospective cohort study of 440 of a total of 753 patients with proven or probable Exserohilum infection evaluated clinical and radiographic findings, antifungal therapy and associated adverse effects, and outcomes at 6 weeks, 3, 6, 9, and 12 months after diagnosis. Patients were grouped into 4 disease categories: meningitis with/without stroke, spinal or paraspinal infections, meningitis/stroke plus spinal/paraspinal infections, and osteoarticular infections.

Results

Among the 440 patients, 223 (51%) had spinal/paraspinal infection, 82 (19%) meningitis/stroke, 123 (28%) both, and 12 (3%) osteoarticular infection. Of 82 patients with meningitis/stroke, 18 (22%) died; among those surviving, 87% were cured at 12 months. Only 7 (3%) of 223 patients with spinal/paraspinal infection died, but at 12 months, 68% had persistent or worsening pain and only 47% were cured. For the 123 patients with both meningitis/stroke and spinal/paraspinal infection, 10 (8%) died, pain persisted in 72%, and 52% were cured at 12 months. Only 37% of those with osteoarticular infection were cured at 12 months. Adverse events from antifungal therapy were noted at 6 weeks in 71% of patients on voriconazole and 81% on amphotericin B.

Conclusions

Fungal infections related to contaminated methylprednisolone injections culminated in death in 8% of patients. Persistent pain and disability were seen at 12 months in most patients with spinal/paraspinal infections.

Lumbar tinea versicolor and spinal anaesthesia

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The risk of meningitis is very low in lumbar tinea versicolor parturient.

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Meticulous skin preparation to reduce the likelihood of infection transmission into subarachnoid space.

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Chlorhexidine 0.5% with 70% alcohol is antiseptic skin preparation.

Infection to the meningeal layer causing meningitis is one of the most feared complications of spinal anaesthesia. Anaesthetists will avoid spinal anaesthesia for those who are having skin infection at the puncture site. However in obstetric population, anaesthetist will try their best to avoid general anaesthesia due to its unwanted effects and complications. Strict and appropriate antiseptic measures such as chlorhexidine 0.5% with 70% alcohol has been suggested to reduce risk of transmission of microorganisms into subarachnoid space. We reported a parturient who had generalized tinea versicolor at the lumbar area, safely anaesthetized under spinal anaesthesia through meticulous antiseptic skin preparation who required delivery by caesarean section.

Exserohilum Peritonitis in Peritoneal Dialysis in Northern China: A Case Report

Fungal peritonitis is a catastrophic complication of peritoneal dialysis (PD) and often requires termination of PD. It is usually caused by Candida species. Here we report a rare case of Exserohilum peritonitis. The patient was successfully treated with catheter removal and anti-fungal therapy.

Mycotic Rhinitis and Sinusitis in Florida Horses

Rhinitis and sinusitis caused by fungal pathogens were studied in biopsy samples submitted from 52 horses distributed throughout subtropical and tropical regions of Florida. Methods included routine histopathology as well as polymerase chain reaction (PCR) with panfungal/panoomycete primers and DNA sequencing on extracted DNA (DNA barcoding). Granulomatous, pyogranulomatous, and fibrinopurulent lesions in nasal and sinus mucosa were associated with signs of upper airway obstruction and noise as well as nasal discharge. Morphologic and histochemical assessment of cases identified 31 cases of zygomycosis/pythiosis plus 1 mixed infection case, 16 cases of phaeohyphomycosis with 2 additional mixed infection cases, and 3 cases caused by other fungi. Morphologic evidence of Aspergillus sp. infection as a superficial copathogen was found in 2 of the mixed fungal infection cases. PCR and DNA sequencing facilitated identification of fungal pathogens in 11 of 52 cases (21%). No evidence of oomycete infection was found. Histomorphologic features of previously unrecognized forms of equine rhinitis/sinusitis were described, including those caused by Flavodon flavus, Curvularia lunata, Exserohilum rostrata, Alternaria alternata, Alternaria sp., Cladophialophora bantiana, Fusarium solani, and Toxicocladosporium irritans. PCR and DNA sequencing using panfungal and oomycete primers with DNA from formalin-fixed and paraffin-embedded specimens successfully identified the pathogen in phaeohyphomycosis (7/18 cases, 39%), zygomycosis/pythiosis (1/32 cases, 3%), and other nonpigmented fungal infections (3/3 cases, 100%). Zygomycosis and phaeohyphomycosis were the most common forms of fungal rhinitis found in Florida horses.

The care and feeding of a commercial liposomal product: liposomal amphotericin B (AmBisome®)

AmBisome (liposomal amphotericin B) is among the earliest approved liposomal therapeutics, and has been in commercial use since the early 1990s. This review provides examples of non-clinical, regulatory, clinical label expansion, adverse event management, and supply chain control reflecting the real world challenges of a commercial liposomal therapeutic. We review examples of post-approval clinical development in severe lung infections, development of US and European guidance documents around liposomal therapeutics, the creation of a suitable placebo for blinded clinical trials, response to findings of a possible new category of adverse event (what turned out to be pseudohyperphosphatemia), challenges in handling the finished product in a setting with high risk of exposure of the product to temperatures outside of the established label storage conditions, and elements of continuingly increased aseptic processing requirements for manufacturing.

Advances in the diagnosis and treatment of fungal infections of the CNS

Fungal infections of the CNS are challenging to treat and their optimal management requires knowledge of their epidemiology, host characteristics, diagnostic criteria, and therapeutic options. Aspergillus and Cryptococcus species predominate among fungal infections of the CNS. Most of these fungi are ubiquitous, but some have restricted geographical distribution. Fungal infections of the CNS usually originate from primary sites outside the CNS (eg, fungal pneumonia) or occur after inoculation (eg, invasive procedures). Most patients with these infections have immunodeficiencies, but immunocompetent individuals can also be infected through heavy exposure. The infecting fungi can be grouped into moulds, yeasts, and dimorphic fungi. Substantial progress has been made with new diagnostic approaches and the introduction of novel antifungal drugs, but fungal infections of the CNS are frequently lethal because of diagnostic delays, impaired drug penetration, resistance to antifungal treatments, and inadequate restoration of immune function. To improve outcomes, future research should advance diagnostic methods (eg, molecular detection and fungus identification), develop antifungal compounds with enhanced CNS-directed efficacy, and further investigate crucial host defence mechanisms.

Detection of mucormycetes and other pathogenic fungi in formalin fixed paraffin embedded and fresh tissues using the extended region of 28S rDNA

Molecular methods of detection based on DNA-sequencing of the internal transcribed spacer 1 and 2 (ITS1 and ITS2) or 5΄ end region of 28S (D1-D2 region) of ribosomal RNA gene (rDNA) have been used extensively for molecular identification and detection of fungal infections. However, these regions are not always informative for identification of mucormycetes and other rare fungal pathogens as they often contain large introns, heterogenic regions, and/or cannot be PCR-amplified using broad range fungal PCR primers. In addition, because of the difficulties of recovering intact fungal DNA from human specimens, smaller regions of DNA are more useful for the direct detection of fungal DNA in tissues and fluids. In this study, we investigated the utility of 12F/13R PCR primers targeting a 200-230 bp region of the extended 28S region of rDNA for molecular identification of fungal DNA in formalin fixed paraffin embedded tissues and other clinical specimens. We demonstrated that this region can be successfully used for identification of all genera and some species of clinically relevant mucormycetes, as well as other medically important fungi, such as Aspergillus, Fusarium, Coccidioides, and Cryptococcus. We also demonstrated that PCR amplification and direct sequencing of the extended 28S region of rDNA was more sensitive compared to targeting the ITS2 region, as we were able to detect and identify mucormycetes and other fungal pathogens in tissues from patients with histopathological and/or culture evidence of fungal infections that were negative with PCR using ITS-specific primers.

Multiplexed analysis of fixed tissue RNA using Ligation in situ Hybridization

Clinical tissues are prepared for histological analysis and long-term storage via formalin fixation and paraffin embedding (FFPE). The FFPE process results in fragmentation and chemical modification of RNA, rendering it less suitable for analysis by techniques that rely on reverse transcription (RT) such as RT-qPCR and RNA-Seq. Here we describe a broadly applicable technique called ‘Ligation in situ Hybridization’ (‘LISH’), which is an alternative methodology for the analysis of FFPE RNA. LISH utilizes the T4 RNA Ligase 2 to efficiently join adjacent chimeric RNA–DNA probe pairs hybridized in situ on fixed RNA target sequences. Subsequent treatment with RNase H releases RNA-templated ligation products into solution for downstream analysis. We demonstrate several unique advantages of LISH-based assays using patient-derived FFPE tissue. These include >100-plex capability, compatibility with common histochemical stains and suitability for analysis of decade-old materials and exceedingly small microdissected tissue fragments. High-throughput DNA sequencing modalities, including single molecule sequencing, can be used to analyze ligation products from complex panels of LISH probes (‘LISH-seq’), which can be amplified efficiently and with negligible bias. LISH analysis of FFPE RNA is a novel methodology with broad applications that range from multiplexed gene expression analysis to the sensitive detection of infectious organisms.

Fungal Infections Associated with Contaminated Steroid Injections

In mid-September 2012, the largest healthcare-associated outbreak in U.S. history began. Before it was over, 751 patients were reported with fungal meningitis, stroke, spinal or paraspinal infection, or peripheral osteoarticular infection, and 64 (8.5%) died. Most patients had undergone epidural injection, and a few osteoarticular injection, of methylprednisolone acetate that had been manufactured at the New England Compounding Center (NECC). The offending pathogen in most cases was Exserohilum rostratum, a brown-black soil organism that previously was a rare cause of human infection. Three lots of methylprednisolone were contaminated with mold at NECC; the mold from unopened bottles of methylprednisolone was identical by whole-genome sequencing to the mold that was isolated from ill patients. Early cases manifested as meningitis, some patients suffered posterior circulation strokes, and later cases were more likely to present with localized infection at the injection site, including epidural abscess or phlegmon, vertebral diskitis or osteomyelitis, and arachnoiditis with intradural involvement of nerve roots. Many patients with spinal or paraspinal infection required surgical intervention. Recommendations for treatment evolved over the first few weeks of the outbreak. Initially, combination therapy with liposomal amphotericin B and voriconazole was recommended for all patients; later, combination therapy was recommended only for those who were most ill, and voriconazole monotherapy was recommended for most patients. Among those patients who continued antifungal therapy for at least 6 months, outcomes for most appeared to be successful, although a few patients remain on therapy.

High clinical suspicion of donor-derived disease leads to timely recognition and early intervention to treat solid organ transplant-transmitted lymphocytic choriomeningitis virus

Despite careful donor screening, unexpected donor-derived infections continue to occur in organ transplant recipients (OTRs). Lymphocytic choriomeningitis virus (LCMV) is one such transplant-transmitted infection that in previous reports has resulted in a high mortality among the affected OTRs. We report a LCMV case cluster that occurred 3 weeks post-transplant in three OTRs who received allografts from a common organ donor in March 2013. Following confirmation of LCMV infection at Centers for Disease Control and Prevention, immunosuppression was promptly reduced and ribavirin and/or intravenous immunoglobulin therapy were initiated in OTRs. The liver recipient died, but right kidney recipients survived without significant sequelae and left kidney recipient survived acute LCMV infection with residual mental status deficit. Our series highlights how early recognition led to prompt therapeutic intervention, which may have contributed to more favorable outcome in the kidney transplant recipients.

The Carbohydrate Lectin Receptor Dectin-1 Mediates the Immune Response to Exserohilum rostratum

Dematiaceous molds are found ubiquitously in the environment and cause a wide spectrum of human disease, including infections associated with high rates of mortality. Despite this, the mechanism of the innate immune response has been less well studied, although it is key in the clearance of fungal pathogens. Here, we focus on Exserohilum rostratum, a dematiaceous mold that caused 753 infections during a multistate outbreak due to injection of contaminated methylprednisolone. We show that macrophages are incapable of phagocytosing Exserohilum Despite a lack of phagocytosis, macrophage production of tumor necrosis factor alpha is triggered by hyphae but not spores and depends upon Dectin-1, a C-type lectin receptor. Dectin-1 is specifically recruited to the macrophage-hyphal interface but not the macrophage-spore interface due to differences in carbohydrate antigen expression between these two fungal forms. Corticosteroid and antifungal therapy perturb this response, resulting in decreased cytokine production. In vivo soft tissue infection in wild-type mice demonstrated that Exserohilum provokes robust neutrophilic and granulomatous inflammation capable of thwarting fungal growth. However, coadministration of methylprednisolone acetate results in robust hyphal tissue invasion and a significant reduction in immune cell recruitment. Our results suggest that Dectin-1 is crucial for macrophage recognition and the macrophage response to Exserohilum and that corticosteroids potently attenuate the immune response to this pathogen.

Bone and Joint Infections due to Haemophilus parainfluenzae: Case Report and Review of the Literature

Haemophilus parainfluenzae is a normal inhabitant of the human respiratory tract. However it is an increasingly recognized pathogen in invasive infections, particularly in the immunocompromised host and where there is disruption of the normal skin or mucosal barriers. We present a case of a 56-year-old female with a history of asplenia who developed H. parainfluenzae septic arthritis of the hip following an intra-articular steroid injection. We also summarize previously reported cases of bone and joint infections caused by H. parainfluenzae.

Risk factors and the clinical and surgical features of fungal prosthetic joint infections: A retrospective analysis of eight cases

Fungal prosthetic joint infections (PJI) and reports of their clinical investigation are rare. In addition, there has been little evidence regarding the outcome of the two-stage exchange protocol for the treatment of fungal PJI. In order to investigate the risk factors and clinical, microbiological and pathological features of fungal PJIs, as well as the effects of the two-stage exchange protocol on their outcome, the present study analyzed eight retrospective fungal PJI cases, involving four cases affecting the hips and four affecting the knees, between May 2000 and March 2012. In all cases, a cemented spacer saturated with antimicrobials was used during the two-stage exchange protocol, and systematic antifungal agents were administrated during the interim period. The average follow-up duration was 4.4 years. Of the eight cases, six had undergone additional surgery on the infected joint prior to infection with the fungus. Following histological analyses, it was determined that the average number of polymorphonuclear cells in the three patients infected with a fungus was only <5/high power field (HPF; magnification, ×400), and that of the five patients with a hybrid infection was >5/HPF. The average Harris Hip scores or Hospital for Special Surgery knee scores were 43.6 preoperatively and 86 at the last follow-up. The two-stage exchange protocol was performed eight times in seven cases, with a failure rate of 12.5%. The remaining case was successfully treated by resection arthroplasty. The average duration of antifungal agent administration during the interim period in five of the eight cases was 1.5 months. For three of the patients, the duration of antifungal agent administration was prolonged until the c-reactive protein levels were decreased to normal. The average duration of spacer implantation into the joint was 4.3 months. The results of the present study suggested that undergoing surgery on a prosthetic joint may be a potential risk factor for the development of fungal PJI. In addition, infiltration of polymorphonuclear leukocytes into the site of the infection may not occur at the same rate as bacterial PJI. Therefore, a two-stage exchange protocol with implantation of a cement spacer saturated with antimicrobials may be considered an effective therapeutic strategy for the treatment of fungal PJI.

In Vitro Activities of Eight Antifungal Drugs against a Global Collection of Genotyped Exserohilum Isolates

The in vitro susceptibilities of 24 worldwide Exserohilum isolates belonging to 10 species from human and environmental sources were determined for eight antifungal drugs. The strains were characterized by internal transcribed spacer (ITS) sequencing and amplified fragment length polymorphism fingerprinting. Posaconazole had the lowest geometric mean MIC (0.16 μg/ml), followed by micafungin (0.21 μg/ml), amphotericin B (0.24 μg/ml), itraconazole (0.33 μg/ml), voriconazole (0.8 μg/ml), caspofungin (1.05 μg/ml), isavuconazole (1.38 μg/ml), and fluconazole (15.6 μg/ml).

The roles of sexual and asexual reproduction in the origin and dissemination of strains causing fungal infectious disease outbreaks

Sexual reproduction commonly refers to the reproductive process in which genomes from two sources are combined into a single cell through mating and then the zygote genomes are partitioned to progeny cells through meiosis. Reproduction in the absence of mating and meiosis is referred to as asexual or clonal reproduction. One major advantage of sexual reproduction is that it generates genetic variation among progeny which may allow for faster adaptation of the population to novel and/or stressful environments. However, adaptation to stressful or new environments can still occur through mutation, in the absence of sex. In this review, we analyzed the relative contributions of sexual and asexual reproduction in the origin and spread of strains causing fungal infectious diseases outbreaks. The necessity of sex and the ability of asexual fungi to initiate outbreaks are discussed. We propose a framework that relates the modes of reproduction to the origin and propagation of fungal disease outbreaks. Our analyses suggest that both sexual and asexual reproduction can play critical roles in the origin of outbreak strains and that the rapid spread of outbreak strains is often accomplished through asexual expansion.

Outbreak of fungal infections associated with contaminated methylprednisolone acetate: an update

In September 2012, an unprecedented outbreak of fungal infections due to preservative-free, injectable methylprednisolone acetate (MPA) was identified. Exserohilum rostratum was quickly identified as the predominant organism involved in disease cases. Prior to this outbreak, little was known about the pathogenesis, treatment, and prognosis of infections due to this unusual brown-black mold. Almost 2 years after the onset of this outbreak, numerous epidemiologic and basic science studies have provided some guidance in understanding the epidemiology, clinical findings, diagnosis, and treatment of patients exposed to the contaminated medication. Additionally, this outbreak has directly led to the passage of legislation supporting increased regulation in the industry of pharmaceutical compounding. Many unanswered questions, particularly surrounding the long-term prognosis and outcomes for affected patients remain. However, it is clear that a strong relationship between clinicians caring for patients and public health as well as a rapid, effective public health response was critical in preventing additional cases of disease.

Black Molds and Melanized Yeasts Pathogenic to Humans

A review is given of melanized fungi involved in human infection, including species forming budding cells and strictly filamentous representatives. Classically, they are known as "phaeoid" or "dematiaceous" fungi, and, today, agents are recognized to belong to seven orders of fungi, of which the Chaetothyriales and Pleosporales are the most important. Infections range from cutaneous or pulmonary colonization to systemic or disseminated invasion. Subcutaneous involvement, either primary or after dissemination, may lead to host tissue proliferation of dermis or epidermis. Particularly in the Chaetothyriales, subcutaneous and systemic infections may occur in otherwise apparently healthy individuals. Infections are mostly chronic and require extended antifungal therapy and/or surgery.

Whole-genome analysis of Exserohilum rostratum from an outbreak of fungal meningitis and other infections

Exserohilum rostratum was the cause of most cases of fungal meningitis and other infections associated with the injection of contaminated methylprednisolone acetate produced by the New England Compounding Center (NECC). Until this outbreak, very few human cases of Exserohilum infection had been reported, and very little was known about this dematiaceous fungus, which usually infects plants. Here, we report using whole-genome sequencing (WGS) for the detection of single nucleotide polymorphisms (SNPs) and phylogenetic analysis to investigate the molecular origin of the outbreak using 22 isolates of E. rostratum retrieved from 19 case patients with meningitis or epidural/spinal abscesses, 6 isolates from contaminated NECC vials, and 7 isolates unrelated to the outbreak. Our analysis indicates that all 28 isolates associated with the outbreak had nearly identical genomes of 33.8 Mb. A total of 8 SNPs were detected among the outbreak genomes, with no more than 2 SNPs separating any 2 of the 28 genomes. The outbreak genomes were separated from the next most closely related control strain by ∼136,000 SNPs. We also observed significant genomic variability among strains unrelated to the outbreak, which may suggest the possibility of cryptic speciation in E. rostratum.

Rift valley Fever virus encephalitis is associated with an ineffective systemic immune response and activated T cell infiltration into the CNS in an immunocompetent mouse model

Background

Rift Valley fever virus (RVFV) causes outbreaks of severe disease in livestock and humans throughout Africa and the Arabian Peninsula. In people, RVFV generally causes a self-limiting febrile illness but in a subset of individuals, it progresses to more serious disease. One manifestation is a delayed-onset encephalitis that can be fatal or leave the afflicted with long-term neurologic sequelae. In order to design targeted interventions, the basic pathogenesis of RVFV encephalitis must be better understood.

Methodology/Principal Findings

To characterize the host immune responses and viral kinetics associated with fatal and nonfatal infections, mice were infected with an attenuated RVFV lacking NSs (ΔNSs) that causes lethal disease only when administered intranasally (IN). Following IN infection, C57BL/6 mice developed severe neurologic disease and succumbed 7–9 days post-infection. In contrast, inoculation of ΔNSs virus subcutaneously in the footpad (FP) resulted in a subclinical infection characterized by a robust immune response with rapid antibody production and strong T cell responses. IN-inoculated mice had delayed antibody responses and failed to clear virus from the periphery. Severe neurological signs and obtundation characterized end stage-disease in IN-inoculated mice, and within the CNS, the development of peak virus RNA loads coincided with strong proinflammatory responses and infiltration of activated T cells. Interestingly, depletion of T cells did not significantly alter survival, suggesting that neurologic disease is not a by-product of an aberrant immune response.

Conclusions/Significance

Comparison of fatal (IN-inoculated) and nonfatal (FP-inoculated) ΔNSs RVFV infections in the mouse model highlighted the role of the host immune response in controlling viral replication and therefore determining clinical outcome. There was no evidence to suggest that neurologic disease is immune-mediated in RVFV infection. These results provide important insights for the future design of vaccines and therapeutic options.

Rift Valley fever virus (RVFV) is a mosquito-borne virus that causes severe disease in people and livestock throughout Africa and the Arabian Peninsula. Human disease is usually self-limiting, but a small proportion of individuals develop fatal encephalitis. The role of the host immune response in determining disease outcome is largely unknown. In order to compare the quality and character of immune responses in nonfatal and fatal cases, we used an attenuated RVFV to inoculate mice by two routes. Subcutaneous inoculation resulted in a subclinical systemic infection that was rapidly cleared due to a robust adaptive response. In contrast, intranasal inoculation stimulated weaker immune responses that failed to control virus replication and culminated in uniformly fatal encephalitis. With many encephalitic viruses, the onset of disease is mediated by changes in blood brain barrier permeability and often, subsequent injury to the CNS by an uncontrolled immune response. However, our results suggest that development of RVFV disease does not depend on either mechanism, but rather results from direct virus-mediated damage in the CNS. Future therapeutic drug design should take into account all possible routes of virus exposure as well as the role of therapies that boost the adaptive response to better combat disease.

Methylprednisolone enhances the growth of Exserohilum rostratum in vitro, attenuates spontaneous apoptosis, and increases mortality rates in immunocompetent Drosophila flies

High concentrations of methylprednisolone (0.32 mg/mL) accelerated growth and attenuated spontaneous apoptosis of Exserohilum rostratum in vitro. Injection of E. rostratum conidia preexposed to 0.32 mg/mL of methylprednisolone for 7 days in immunocompetent flies led to increased mortality and a higher fungal burden. Exposure to methylprednisolone could enhance the virulence of E. rostratum.

Lessons learned in the multistate fungal infection outbreak in the United States

PURPOSE OF REVIEW

The recent outbreak of fungal meningitis related to contaminated methylprednisolone acetate injections represents an important cause of morbidity and continues to be a significant public health problem in the United States.

RECENT FINDINGS

As of August 2013, there have been 749 cases and 63 deaths in 20 states associated with epidemic fungal meningitis, most of these because of Exserohilum rostratum. Clinical experience in managing these cases has grown dramatically in the last several months; most patients require at least 6 months of antifungal therapy for complicated disease. Most patients are treated with voriconazole, with or without liposomal amphotericin B, for central nervous system and paraspinal complications of the disease. For disease involving the sacroiliac and peripheral joints, voriconazole alone has been preferred. MRI spine imaging has identified several cases of asymptomatic disease, suggesting an aggressive diagnostic approach to exposed asymptomatic patients. Mortality remains low (<10%), but morbidity relating to persistent symptoms and treatment-associated toxicity is high.

SUMMARY

The ongoing fungal meningitis epidemic demonstrates an important achievement for the public health community. Important questions remain relating to the diagnosis, management, and long-term outcomes of these patients. Important research questions pertaining to specific risks influencing disease manifestations remain unanswered.

Scedosporium prolificans osteomyelitis following penetrating injury: A case report

Scedosporium prolificans are opportunistic moulds that can cause mycetoma following penetrating injuries. This fungus is more virulent than other species and treatment options are limited. Here we describe the first known case in the UK of S. prolificans osteomyelitis, in a 4 year old following penetrating injury. Successful outcome with limb salvage and foot function is achieved after repeated surgical debridement, and combination chemotherapy with voriconazole/terbinafine.

Fungal central nervous system infections: prevalence and diagnosis

Fungal infections of the central nervous system (CNS) are rare but they pose a significant challenge. Their prevalence spans a wide array of hosts including immunosuppressed and immunocompetent individuals, patients undergoing neurosurgical procedures and those carrying implantable CNS devices. Cryptococcus neoformans and Aspergillus spp. remain the most common pathogens. Magnetic resonance imaging can help localize the lesions, but diagnosis is challenging since invasive procedures may be needed for the retrieval of tissue, especially in cases of fungal abscesses. Antigen and antibody tests are available and approved for use in the cerebrospinal fluid (CSF). PCR-based techniques are promising but they are not validated for use in the CSF. This review provides an overview on the differential diagnosis of the fungal CNS disease based on the host and the clinical syndrome and suggests the optimal use of diagnostic techniques. It also summarizes the emergence of Cryptococcus gatti and an unanticipated outbreak caused by Exserohilum rostratum.

Fungal infections associated with contaminated methylprednisolone injections

BACKGROUND

Fungal infections are rare complications of injections for treatment of chronic pain. In September 2012, we initiated an investigation into fungal infections associated with injections of preservative-free methylprednisolone acetate that was purchased from a single compounding pharmacy.

METHODS

Three lots of methylprednisolone acetate were recalled by the pharmacy; examination of unopened vials later revealed fungus. Notification of all persons potentially exposed to implicated methylprednisolone acetate was conducted by federal, state, and local public health officials and by staff at clinical facilities that administered the drug. We collected clinical data on standardized case-report forms, and we tested for the presence of fungi in isolates and specimens by examining cultures and performing polymerase-chain-reaction assays and histopathological and immunohistochemical testing.

RESULTS

By October 19, 2012, more than 99% of 13,534 potentially exposed persons had been contacted. As of July 1, 2013, there were 749 reported cases of infection in 20 states, with 61 deaths (8%). Laboratory evidence of Exserohilum rostratum was present in specimens from 153 case patients (20%). Additional data were available for 728 case patients (97%); 229 of these patients (31%) had meningitis with no other documented infection. Case patients had received a median of 1 injection (range, 1 to 6) of implicated methylprednisolone acetate. The median age of the patients was 64 years (range, 15 to 97), and the median incubation period (the number of days from the last injection to the date of the first diagnosis) was 47 days (range, 0 to 249); 40 patients (5%) had a stroke.

CONCLUSIONS

Analysis of data from a large, multistate outbreak of fungal infections showed substantial morbidity and mortality. The infections were associated with injection of a contaminated glucocorticoid medication from a single compounding pharmacy. Rapid public health actions included prompt recall of the implicated product, notification of exposed persons, and early outreach to clinicians.

Clinical findings for fungal infections caused by methylprednisolone injections

BACKGROUND

Since September 18, 2012, public health officials have been investigating a large outbreak of fungal meningitis and other infections in patients who received epidural, paraspinal, or joint injections with contaminated lots of methylprednisolone acetate. Little is known about infections caused by Exserohilum rostratum, the predominant outbreak-associated pathogen. We describe the early clinical course of outbreak-associated infections.

METHODS

We reviewed medical records for outbreak cases reported to the Centers for Disease Control and Prevention before November 19, 2012, from the six states with the most reported cases (Florida, Indiana, Michigan, New Jersey, Tennessee, and Virginia). Polymerase-chain-reaction assays and immunohistochemical testing were performed on clinical isolates and tissue specimens for pathogen identification.

RESULTS

Of 328 patients without peripheral-joint infection who were included in this investigation, 265 (81%) had central nervous system (CNS) infection and 63 (19%) had non-CNS infections only. Laboratory evidence of E. rostratum was found in 96 of 268 patients (36%) for whom samples were available. Among patients with CNS infections, strokes were associated with an increased severity of abnormalities in cerebrospinal fluid (P<0.001). Non-CNS infections were more frequent later in the course of the outbreak (median interval from last injection to diagnosis, 39 days for epidural abscess and 21 days for stroke; P<0.001), and such infections developed in patients with and in those without meningitis.

CONCLUSIONS

The initial clinical findings from this outbreak suggest that fungal infections caused by epidural and paraspinal injection of a contaminated glucocorticoid product can result in a broad spectrum of clinical disease, reflecting possible variations in the pathogenic mechanism and in host and exposure risk factors. (Funded by the Centers for Disease Control and Prevention.).

Preliminary laboratory report of fungal infections associated with contaminated methylprednisolone injections

In September 2012, the Centers for Disease Control and Prevention (CDC) initiated an outbreak investigation of fungal infections linked to injection of contaminated methylprednisolone acetate (MPA). Between 2 October 2012 and 14 February 2013, the CDC laboratory received 799 fungal isolates or human specimens, including cerebrospinal fluid (CSF), synovial fluid, and abscess tissue, from 469 case patients in 19 states. A novel broad-range PCR assay and DNA sequencing were used to evaluate these specimens. Although Aspergillus fumigatus was recovered from the index case, Exserohilum rostratum was the primary pathogen in this outbreak and was also confirmed from unopened MPA vials. Exserohilum rostratum was detected or confirmed in 191 specimens or isolates from 150 case patients, primarily from Michigan (n=67 patients), Tennessee (n=26), Virginia (n=20), and Indiana (n=16). Positive specimens from Michigan were primarily abscess tissues, while positive specimens from Tennessee, Virginia, and Indiana were primarily CSF. E. rostratum antifungal susceptibility MIC50 and MIC90 values were determined for voriconazole (1 and 2 μg/ml, respectively), itraconazole (0.5 and 1 μg/ml), posaconazole (0.5 and 1 μg/ml), isavuconazole (4 and 4 μg/ml), and amphotericin B (0.25 and 0.5 μg/ml). Thirteen other mold species were identified among case patients, and four other fungal genera were isolated from the implicated MPA vials. The clinical significance of these other fungal species remains under investigation. The laboratory response provided significant support to case confirmation, enabled linkage between clinical isolates and injected vials of MPA, and described significant features of the fungal agents involved in this large multistate outbreak.

Fungal disease following contaminated steroid injections: Exserohilum is ready for its close-up

This Commentary highlights the article by Ritter et al. that reported the pathology associated with the recent fungal outbreak associated with contaminated methylprednisolone acetate injections.