Epidemiology and clinical spectrum of blastomycosis diagnosed at Manitoba hospitals

Clinical Characteristics and Outcomes of Endemic Mycoses After Solid Organ Transplantation: A Comprehensive Review

Background

Geographically endemic fungi can cause significant disease among solid organ transplant (SOT) recipients. We provide an update on the epidemiology, clinical presentation, and outcomes of 5 endemic mycoses in SOT recipients.

Methods

Multiple databases were reviewed from inception through May 2023 using key words for endemic fungi (eg, coccidioidomycosis or Coccidioides, histoplasmosis or Histoplasma, etc). We included adult SOT recipients and publications in English or with English translation.

Results

Among 16 cohort studies that reported on blastomycosis (n = 3), coccidioidomycosis (n = 5), histoplasmosis (n = 4), and various endemic mycoses (n = 4), the incidence rates varied, as follows: coccidioidomycosis, 1.2%-5.8%; blastomycosis, 0.14%-0.99%; and histoplasmosis, 0.4%-1.1%. There were 204 reports describing 268 unique cases of endemic mycoses, including 172 histoplasmosis, 31 blastomycosis, 34 coccidioidomycosis, 6 paracoccidioidomycosis, and 25 talaromycosis cases. The majority of patients were male (176 of 261 [67.4%]). Transplanted allografts were mostly kidney (192 of 268 [71.6%]), followed by liver (n = 39 [14.6%]), heart (n = 18 [6.7%]), lung (n = 13 [4.9%]), and combined kidney-liver and kidney-pancreas (n = 6 [2.7%]). In all 5 endemic mycoses, most patients presented with fever (162 of 232 [69.8%]) and disseminated disease (179 of 268 [66.8%]). Cytopenias were frequently reported for histoplasmosis (71 of 91 [78.0%]), coccidioidomycosis (8 of 11 [72.7%]) and talaromycosis (7 of 8 [87.5%]). Graft loss was reported in 12 of 136 patients (8.8%). Death from all-causes was reported in 71 of 267 (26.6%); half of the deaths (n = 34 [50%]) were related to the underlying mycoses.

Conclusions

Endemic mycoses commonly present with fever, cytopenias and disseminated disease in SOT recipients. There is a relatively high all-cause mortality rate, including many deaths that were attributed to endemic mycoses.

Retropharyngeal Blastomycosis Abscess Causing Osteomyelitis, Discitis, Cervical Deformity, and Cervical Epidural Abscess: A Case Report

Blastomycosis infection is caused by the inhalation of the spores of the dimorphic Blastomyces sp.fungus. While more commonly a self-limited infection of the lungs, extrapulmonary manifestations arise from hematogenous or contiguous spread. Disseminated infection most often includes skin lesions and osteomyelitis; however, central nervous system (CNS) involvement is infrequently reported in the literature. Herein, we present a case of a retropharyngeal blastomycosis abscess leading to cervical spine osteonecrosis with retropulsion, deformity, and a spinal epidural abscess, and we discuss the relevant literature. The patient was successfully treated with cervical traction, followed by a combined anterior-posterior cervical approach, including abscess drainage, corpectomies, and instrumented fixation. Postoperatively, the patient completed 12 months of voriconazole and had near resolution of preoperative symptoms. Expediting neurosurgical intervention, such as the utilization of decompression, the clearance of infectious burden, and the correction of alignment, is critical for preventing downstream complications. Retropharyngeal blastomycosis abscesses are rare, and we report one of the rare instances of dissemination to and the degeneration of the cervical spine.

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.

Blastomycosis-Some Progress but Still Much to Learn

Blastomycosis, caused by Blastomyces spp., is an endemic mycosis capable of causing significant disease throughout the body. Higher rates of infection are seen in the Mississippi and Ohio River valleys, the Great Lakes region of the United States and Canada, much of Africa, and, to a lesser extent, in India and the Middle East. Limited reporting inhibits our true understanding of the geographic distribution of blastomycosis. An estimated 50% of those infected remain asymptomatic. Of those who present with symptomatic disease, pulmonary involvement is most common, while the most common extrapulmonary sites are the skin, bones, genitourinary system, and central nervous system. Itraconazole is the standard therapy for mild-moderate disease. Data for other azoles are limited. Amphotericin is used for severe disease, and corticosteroids are occasionally used in severe disease, but evidence for this practice is limited. Despite increasing incidence and geographic reach in recent years, there are still significant knowledge gaps in our understanding of blastomycosis. Here, we provide an updated review of the epidemiology, clinical presentations, and diagnostic and therapeutic approaches for this infection. We also discuss areas needing further research.

Let's talk about Sex Characteristics - as a Risk Factor for Invasive Fungal Diseases

Biological sex, which comprises differences in host sex hormone homeostasis and immune responses, can have a substantial impact on the epidemiology of infectious diseases. Comprehensive data on sex distributions in invasive fungal diseases (IFDs) is lacking. In this review we performed a literature search of in vitro/animal studies, clinical studies, systematic reviews, and meta-analyses of invasive fungal infections. Females represented 51.2% of invasive candidiasis cases, mostly matching the proportions of females among the general population in the United States and Europe (>51%). In contrast, other IFDs were overrepresented in males, including invasive aspergillosis (51% males), mucormycosis (60%), cryptococcosis (74%), coccidioidomycosis (70%), histoplasmosis (61%), and blastomycosis (66%). Behavioral variations, as well as differences related to biological sex, may only in part explain these findings. Further investigations concerning the association between biological sex/gender and the pathogenesis of IFDs is warranted.

Risk factors of severe blastomycosis and comparison of diagnosis and outcomes between immunocompetent and immunocompromised patients

BACKGROUND

Blastomycosis is an endemic fungal infection that causes pulmonary and systemic disease. It can occur irrespective of the patient's immune status. The risk factors associated with the severity of the disease are not well studied.

METHODS

This is a retrospective study of patients admitted with blastomycosis at the University of Kentucky Hospital from 2004 to 2019. Logistic regression was used to identify variables associated with severe blastomycosis.

RESULTS

A total of 76 patients were identified; 22 (28.9%) had at least one immunosuppressive condition. Pulmonary blastomycosis was reported in 49/76 (65%) of the patients and disseminated infection in 27/76 (35.5%). All diagnostic tests were not significantly different in diagnostic results in immunocompromised vs immunocompetent patients. Cultures and histopathology were positive in 56/61 (91.8%) and 54/63 (85.7%) respectively. Blastomyces or Histoplasma antigen test was positive in 13/17 (76.4%) in immunocompromised patients compared to 26/42 (61.9%) in immunocompetent patients. Immunocompromised patients were more likely to be admitted to the hospital and ICU compared to immunocompetent patients. In the multivariate analysis, pulmonary multilobar disease (RR 5.68; 95% CI 2.13-15.15), obesity (RR 2.39; 95% CI 1.26-4.51), diabetes mellitus (RR 3.50; 95% CI 1.38-8.90) and immunosuppression (RR 2.28; 95% CI 1.14-4.56) were significant independent risk factors for severe blastomycosis. Inpatient mortality proportion was higher in immunocompromised patients but not statistically significant.

CONCLUSION

Pulmonary multilobar disease, obesity, diabetes mellitus and immunosuppression were risk factors associated with severe blastomycosis. Immunocompromised patients required more frequent hospitalisations compared to immunocompetent patients.

Changing Patterns of Disease Severity in Blastomyces dermatitidis Infection, Quebec, Canada

The increase in severe cases might be related to an increased number of immunosuppressed patients; climate change might also play a role.

This retrospective multicenter cohort study assessed temporal changes in the severity and mortality rate of blastomycosis in Quebec, Canada, and identified risk factors for death in patients with blastomycosis in 1988–2016. The primary outcome was 90-day all-cause deaths. Among 185 patients, 122 (66%) needed hospitalization and 30 (16%) died. We noted increases in the proportion of severe cases, in age at diagnosis and in the proportion of diabetic and immunocompromised patients over time. Independent risk factors for death were age (adjusted odds ratio [aOR] 1.04, 95% CI 1.00–1.07), immunosuppression (aOR 4.2, 95% CI 1.5–11.6), and involvement of >2 lung lobes (aOR 5.3, 95% CI 1.9–14.3). There was no association between the Blastomyces genotype group and all-cause mortality. The proportion of severe cases of blastomycosis has increased in Quebec over the past 30 years, partially explained by the higher number of immunosuppressed patients.

Blastomycosis in Africa and the Middle East: A Comprehensive Review of Reported Cases and Reanalysis of Historical Isolates Based on Molecular Data

BACKGROUND

Blastomycosis has been reported from countries in Africa and the Middle East, but a decades-long debate has persisted regarding whether this is the same disease known in North America and caused by Blastomyces dermatitidis and Blastomyces gilchristii.

METHODS

We reviewed published cases of human and veterinary blastomycosis from Africa and the Middle East. We abstracted epidemiological and clinical features of cases, including sites of disease, diagnosis, management, outcomes, and, where available, genetic and antigenic typing of case isolates. In addition, we sequenced nucleic acids from 9 clinical isolates from Africa deposited in global collections as B. dermatitidis; for 5, we sequenced the internal transcribed spacer regions, and for the other 4 we sequenced the whole genomes.

RESULTS

We identified 172 unique human patients with blastomycosis, including 159 patients from 25 African countries and 12 patients from 5 Middle Eastern countries, and also identified 7 reports of veterinary blastomycosis. In humans, cutaneous disease predominated (n = 100/137, 73%), followed by pulmonary (n = 73/129, 57%) and osteoarticular involvement (n = 61/128, 48%). Unusual direct microscopy/histopathological presentations included short hyphal fragments in tissues (n = 23/129, 18%). There were 34 genotyped case isolates that comprised 4 species: Blastomyces percursus (n = 22, 65%), from 8 countries throughout all regions; Blastomyces emzantsi (n = 9, 26%), from South Africa; B. dermatitidis (n = 1, 3%), from the Democratic Republic of Congo; and B. gilchristii (n = 2, 6%), from South Africa and Zimbabwe.

CONCLUSIONS

Blastomycosis occurs throughout Africa and the Middle East and is caused predominantly by B. percursus and, at least in South Africa, B. emzantsi, resulting in distinct clinical and pathological patterns of disease.

Blastomycosis in 64 Wisconsin Children: Unanticipated Infection Risk and Severity in Urban Residents

BACKGROUND

Blastomycosis, an endemic mycosis of immunocompetent individuals, is typically seen after exposure to waterways within rural wooded regions. It is not considered a disease of urban environments. Infection can be solely pneumonic or disseminate to skin, bone or central nervous system. Unknown factors influence disease acquisition and severity in children.

METHODS

We analyzed acquisition risks and disease characteristics of blastomycosis in children seen at a tertiary care center from 1998 to 2018 to identify potential exposure sources, measure disease severity and assess the effect of race upon disease severity.

RESULTS

Of 64 infected children, mean age was 12.9 years, with median time to diagnosis 38.5 days. About 72% were male, 38% resided in urban counties and 50% had typical environmental exposure. Isolated pulmonary infection occurred in 33 (52%). The remainder had evidence of dissemination to skin (N = 13), bone (N = 16; 7 clinically silent) and cranium (N = 7; 3 clinically silent). Infection was moderate/severe in 19 (30%). Two children (3%) died. About 79% of children with moderate/severe disease (P = 0.008) and 71% of urban children (P = 0.007) lacked typical environmental exposure. Comparing children from urban counties to other residences, 63% versus 5% were black (P < 0.001) and 71% versus 35% developed extrapulmonary dissemination (P = 0.006). Moderate/severe disease was seen in 7/17 (42%) black children but only 12/47 (26%) children of other races (P = 0.23).

CONCLUSIONS

Blastomycosis, can be endemic in urban children in the absence of typical exposure history, have frequent, sometimes clinically silent, extrapulmonary dissemination and possibly produces more severe disease in black children.

Central nervous system blastomycosis clinical characteristics and outcomes

Blastomycosis is a local or systemic infection, caused by Blastomyces dermatitidis (B. dermatitidis) or B. gilchristii. Blastomycosis has been described as "the great pretender," alluding to the fact that it manifests in a wide range of symptoms and disease severity. Central nervous system (CNS) involvement, although rare, carries significant mortality. Due to the limited published reports of CNS blastomycosis, we present an updated cohort with eight cases of proven or probable CNS blastomycosis describing presentation, diagnosis, treatment and outcomes. Headache was the most common presenting symptom. Magnetic resonance imaging (MRI) proved to be the superior imaging study. All patients in our cohort were diagnosed by histopathological staining or cultures of tissue or fluid obtained from CNS or extra-CNS lesions. All patients that received treatment with Liposomal amphrotericin B for at least 10 days followed by a prolonged azole therapy did not have relapse. Two patients with late diagnoses died during hospitalization. Our findings confirm the importance of timely diagnosis and treatment of CNS blastomycosis to improve outcomes especially with an azole that have a high CNS penetration and a good intrinsic activity for B. dermatitidis such as voriconazole.

Blastomycosis

Blastomycosis is the fungal disease caused by thermally dimorphic fungi in the genus Blastomyces, with B dermatitidis complex causing most cases. It is considered hyperendemic in areas adjacent to the Great Lakes and along the St. Lawrence, Mississippi, and Ohio rivers, but definitive geographic distribution of blastomycoses remains obscure. Clinical presentation is variable. Disseminated blastomycosis with extrapulmonary manifestations is more common in immunosuppressed individuals. Culture positivity is required for definitive diagnosis, but compatible histology is often sufficient for presumptive diagnosis and initiation of treatment. Treatment should be provided to all symptomatic cases to prevent progression or recurrence.

Outcomes With Severe Blastomycosis and Respiratory Failure in the United States

BACKGROUND

Outcomes of patients with severe pulmonary blastomycosis requiring mechanical ventilation (MV) are not well understood in the modern era. Limited historical case series reported 50-90% mortality in patients with acute respiratory distress syndrome caused by blastomycosis. The objective of this large retrospective cohort study was to describe the risk factors and outcomes of patients with severe pulmonary blastomycosis.

METHODS

We performed a retrospective cohort analysis utilizing the Nationwide Inpatient Sample from 2006-2014. Patients aged >18 years with a diagnosis of blastomycosis who received MV were included.

RESULTS

There were 1848 patients with a diagnosis of blastomycosis included in the study. Of these, 219 (11.9%) underwent MV with a mortality rate of 39.7% compared with 2.5% in patients not requiring ventilatory support (P < .01). The median (IQR) time to death for patients requiring MV was 12 (8-16) days. The median length of hospital stay for survivors of MV was 22 (14-37) days. The rate of MV was higher for patients treated in teaching hospitals (63.4% vs 57.2%, P = .05) and lower for those receiving care at a rural hospital (12.3% vs 17.2%, P = .04). In a multivariate model, female gender was associated with increased risk of mortality (OR, 1.84; 95% CI, 1.06-3.20; P = .03) as was increasing patient age (10-year age increase OR, 1.64; 95% CI, 1.33-2.02; P < .01).

CONCLUSIONS

In the largest published cohort of patients with blastomycosis, mortality for patients on MV is high at ~40%, 16-fold higher than those without MV.

Blastomycosis with rapid-onset acute respiratory distress syndrome in an urban setting

While blastomycosis is endemic to eastern USA and northwestern Ontario, acquisition is an anomaly in urban settings. We present a 54-year-old immunocompetent man from the greater Toronto area with no travel, who presented with a 3-week history of chest pain and dyspnoea. Initial radiographic workup revealed a mass-like opacification in the right apical mediastinum. Extensive investigations including bronchoscopy with bronchoalveolar lavage, mediastinal mass biopsy with fungal and mycobacterial cultures and multiple stains, and CT were unrevealing. The patient progressed to respiratory failure over 4 months. Ultimately, sputum and bone marrow cultures confirmed a diagnosis of disseminated blastomycosis. The patient required prolonged extracorporeal membrane oxygenation and ongoing ventilation postdecannulation. Our case highlights diagnostic challenges with blastomycosis, particularly in immunocompetent individuals with no travel to recreational areas, and emphasises the importance of maintaining a high index of suspicion and sending fungal cultures of appropriate specimens and/or cytopathology in clinically compatible cases.

Analysis and modeling of Blastomyces dermatitidis environmental prevalence in Minnesota using soil collected to compare basal and outbreak levels

Outbreaks of blastomycosis, caused by the fungus Blastomyces dermatitidis, occur in endemic areas of the United States and Canada but the geographic range of blastomycosis is expanding. Previous studies inferred the location of B. dermatitidis through epidemiologic data associated with outbreaks because culture of B. dermatitidis from the environment is often unsuccessful. In this study, we used a culture-independent, PCR-based method to identify B. dermatitidis DNA in environmental samples using the BAD1 promoter region. We tested 250 environmental samples collected in Minnesota, either associated with blastomycosis outbreaks or environmental samples collected from high- and low-endemic regions to determine basal prevalence of B. dermatitidis in the environment. We identified a fifth BAD1 promoter haplotype of B. dermatitidis prevalent in Minnesota. Ecological niche analysis identified latitude, longitude, elevation, and site classification as environmental parameters associated with the presence of B. dermatitidis Using this analysis, a Random Forest model predicted B. dermatitidis presence in basal environmental samples with 75% accuracy. These data support use of culture-independent, PCR-based environmental sampling to track spread into new regions and to characterize the unknown B. dermatitidis environmental niche.Importance Upon inhalation of spores from the fungus Blastomyces dermatitidis from the environment, humans and animals can develop the disease blastomycosis. Based on disease epidemiology, B. dermatitidis is known to be endemic in the United States and Canada around the Great Lakes and in the Ohio and Mississippi River Valleys but is starting to emerge in other areas. B. dermatitidis is extremely difficult to culture from the environment so little is known about the environmental reservoirs for this pathogen. We used a culture-independent PCR-based assay to identify the presence of B. dermatitidis DNA in soil samples from Minnesota. By combining molecular data with ecological niche modeling, we were able to predict the presence of B. dermatitidis in environmental samples with 75% accuracy and to define characteristics of the B. dermatitidis environmental niche. Importantly, we showed the effectiveness of using a PCR-based assay to identify B. dermatitidis in environmental samples.

Unique Oral Presentations of Deep Fungal Infections: A Report of Four Cases

Deep fungal infections rarely involve the oral cavity and most commonly affect immunocompromised patients. Oral deep fungal infections typically manifest as chronic mucosal ulcerations or granular soft tissue overgrowths. Since these lesions are non-specific and can mimic malignancy, it is crucial to obtain a thorough clinical history and an adequate biopsy to render the appropriate diagnosis. We report four new cases of deep fungal infections, diagnosed as histoplasmosis, blastomycosis and chromoblastomycosis, exhibiting unique oral and perioral presentations. Awareness of these unusual entities can help dental and medical practitioners expedite proper multidisciplinary care and minimize morbidity and mortality.

Mortality associated with Blastomyces dermatitidis infection: A systematic review of the literature and meta-analysis

Published case fatality in blastomycosis patients ranges between 4% and 78%. This study aimed to assess mortality associated with blastomycosis and identify its associated risk factors. We conducted a systematic review of publications related to Blastomyces dermatitidis available in PubMed and Scopus databases. Studies that reported data on blastomycosis mortality and that were published from inception through February 2018 were assessed and included in the analysis. Using the R meta package, a random-effect model meta-analysis was used to calculate pooled and stratified estimates of case-fatality proportions and risk ratios. Of 1553 publications, we included 20 studies reporting on a total of 2820 cases of blastomycosis between 1970 and 2014 and three case series reports with 10, 21, and 36 patients. The mean or median ages ranged from 28 to 59 years. Mortality was defined as attributable mortality caused by blastomycosis in 13 studies. Among 14 studies with a standard error ≤0.05, the overall pooled mortality was 6.6% (95% confidence interval [CI], 4.9-8.2) with 57% heterogeneity. The mortality rate was 37% (95% CI, 23-51) in immunocompromised patients and 75% (95% CI, 53-96) in patients who developed an acute respiratory distress syndrome (ARDS) (n = 3 studies each). ARDS was the only identified risk factor in general patients (risk ratio = 10.2). The overall mortality was significantly higher in studies involving immunocompromised patients and ARDS patients. Our analysis showed considerable heterogeneity among studies. Inconsistent mortality definitions may have contributed to the observed heterogeneity. Further research is needed to assess potential risk factors for mortality.

A case of disseminated blastomycosis with pulmonary, genitourinary, and osteoarticular involvement in southern Saskatchewan

Although southern Saskatchewan is not known to be a region endemic to blastomycosis, we present a case of disseminated blastomycosis in a 39-year-old man with pulmonary, genitourinary, and osteoarticular involvement. The patient presented with persistent fevers despite recent antibiotic therapy, arthritis in his left foot, and urinary obstruction. A computed tomography (CT) scan of the chest revealed a diffuse miliary pattern. A transbronchial biopsy only showed granulomatous changes, and washings were negative for fungal culture. Magnetic resonance imaging (MRI) of the left foot revealed signs of septic arthritis. Pathology from the joint aspiration and debridement revealed budding yeast in keeping with blastomycosis. Urine culture also grew blastomycosis, confirming urinary involvement. He was initiated on itraconazole, with complete resolution of his symptoms within 2 weeks. This case illustrates the challenges in diagnosing disseminated blastomycosis, and further establishes the endemicity of blastomycosis in southern Saskatchewan.

Re-drawing the Maps for Endemic Mycoses

Endemic mycoses such as histoplasmosis, coccidioidomycosis, blastomycosis, paracoccidioidomycosis, and talaromycosis are well-known causes of focal and systemic disease within specific geographic areas of known endemicity. However, over the past few decades, there have been increasingly frequent reports of infections due to endemic fungi in areas previously thought to be “non-endemic.” There are numerous potential reasons for this shift such as increased use of immune suppressive medications, improved diagnostic tests, increased disease recognition, and global factors such as migration, increased travel, and climate change. Regardless of the causes, it has become evident that our previous understanding of endemic regions for these fungal diseases needs to evolve. The epidemiology of the newly described Emergomyces is incomplete; our understanding of it continues to evolve. This review will focus on the evidence underlying the established areas of endemicity for these mycoses as well as new data and reports from medical literature that support the re-thinking these geographic boundaries. Updating the endemic fungi maps would inform clinical practice and global surveillance of these diseases.

Blastomyces helicus, a New Dimorphic Fungus Causing Fatal Pulmonary and Systemic Disease in Humans and Animals in Western Canada and the United States

Background

Blastomyces helicus (formerly Emmonsia helica) is a dimorphic fungus first isolated from a man with fungal encephalitis in Alberta, Canada. The geographic range, epidemiology, and clinical features of disease are unknown.

Methods

We reviewed human and veterinary isolates of B. helicus identified among Blastomyces and Emmonsia isolates at the University of Alberta Microfungus Collection and Herbarium, University of Texas Health San Antonio’s Fungus Testing Laboratory, and Associated Regional and University Pathologists Laboratories. Isolates were selected based on low Blastomyces dermatitidis DNA probe values and/or atypical morphology. Species identification was confirmed for most isolates by DNA sequence analysis of the internal transcribed spacer with or without D1/D2 ribosomal RNA regions. Epidemiological and clinical data were analyzed.

Results

We identified isolates from 10 human and 5 veterinary cases of B. helicus infection; all were referred from western regions of Canada and the United States. Isolates remained sterile in culture, producing neither conidia nor sexual spores in the mycelial phase, but often producing coiled hyphae. Isolates were most frequently cultured from blood and bronchoalveolar lavage in humans and lungs in animals. Most infected persons were immunocompromised. Histopathological findings included pleomorphic, small or variably sized yeast-like cells, with single or multiple budding, sometimes proliferating to form short, branching, hyphal-like elements. Disease carried a high case-fatality rate.

Conclusions

Blastomyces helicus causes fatal pulmonary and systemic disease in humans and companion animals. It differs from B. dermatitidis in morphological presentation in culture and in histopathology, by primarily affecting immunocompromised persons, and in a geographic range that includes western regions of North America.

Racial Differences in Clinical Phenotype and Hospitalization of Blastomycosis Patients

Background

Dimorphic fungal infections, such as blastomycosis, cause significant morbidity and mortality. Historically, blastomycosis studies have focused on non-Hispanic whites, which limits our understanding of the clinical presentation and outcomes for patients of other races and ethnicities. We evaluated whether clinical presentation and disease severity varied across racial and ethnic groups.

Methods

Blastomycosis patients were identified from Marshfield Clinic Health System and data were abstracted from electronic medical records. Blastomyces genotyping was performed for cases with available isolates. Bivariate analyses (χ ² tests/analysis of variance) assessed associations of race and/or ethnicity, Blastomyces spp, and hospitalization status with demographics and clinical presentation. Multivariable logistic regression was used to evaluate the association of race and/or ethnicity and hospitalization.

Results

In total, 477 patients were included. Age differences were observed across race and ethnicity categories (P < .0001). Non-Hispanic whites were oldest (median, 48 years; interquartile range [IQR], 31–62) and Asians were youngest (26 years; IQR, 19–41). Non-Hispanic whites (55%) and African Americans (52%) had underlying medical conditions more frequently than Hispanic whites (27%) and Asians (29%). Odds of hospitalization were 2 to 3 times higher for Hispanic whites (adjusted odds ratio [aOR], 2.9; 95% confidence interval [CI], 1.2–1.7), American Indian or Alaska Native (AIAN) (aOR, 2.4; 95% CI, 1.0–5.5), and Asian (aOR, 1.9; 95% CI, 1.0–3.6) patients compared with non-Hispanic white patients. Ninety percent of Blastomyces dermatitidis infections occurred in non-Hispanic whites, whereas blastomycosis in Hispanic whites, AIAN, and Asian patients was frequently caused by Blastomyces gilchristii (P < .0001).

Conclusions

Hispanic whites, AIAN, and Asian blastomycosis patients were younger and healthier but more frequently hospitalized. Patients in these racial and ethnic groups may need more aggressive treatment and closer therapeutic monitoring.

Pleural Effusion in Pulmonary and Extrapulmonary Blastomycosis

OBJECTIVE

Pleural effusion secondary to blastomycosis infection is an uncommon clinical manifestation of the disease. We undertook a retrospective study to assess the incidence and involvement of pleural effusion in patients with blastomycosis infection.

STUDY DESIGN

Institutional cytology and surgical pathology records were searched from December 1995 to October 2017 for cases of blastomycosis. The cytologic, surgical pathology, and clinical pertinent information was reviewed in detail.

RESULTS

A total of 77 cases of blastomycosis infection were recorded, with a male-to-female ratio of 1.7:1.0. Forty-eight cases of blastomycosis were pulmonary (62.3%), while 29 cases of blastomycosis were found in extrapulmonary sites (37.7%). The diagnosis of pulmonary blastomycosis was established by 24 lung biopsies/wedge resections, 22 bronchial alveolar lavages, and 2 lung fine needle aspirations. The 29 cases of extrapulmonary blastomycosis included 13 cases of bone (44.8%), 8 cases of skin (27.6%), 6 cases of soft tissue (20.7%), and 2 cases of brain infections (6.8%). Twenty-eight of 48 pulmonary cases were complicated by unilateral or bilateral pleural effusion (58.3%) detected by imaging studies. Four of the 28 pleural effusions were aspirated and examined by cytology. Two of the 4 pleural fluid cytologies showed involvement by blastomycosis (50%). In the extrapulmonary blastomycosis group, 9 of 29 patients showed unilateral or bilateral pleural effusions (31.0%), including 4 cases of bone, 4 cases of skin, and 1 case of brain involvement. Only 2 of the 9 pleural effusions were aspirated for cytology study. One of the 2 pleural fluid cytologies showed blastomycosis (50%).

CONCLUSION

Pleural effusion detected by imaging is common in blastomycosis patients. Blastomycosis can involve pleural fluid in both pulmonary and extrapulmonary diseases. A broad infectious differential that includes blastomycosis should be considered to make a timely diagnosis and initiate antifungal therapy to prevent systemic infection and further dissemination of the disease.

Endemic fungal infections in solid organ transplant recipients-Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

These updated guidelines from the Infectious Diseases Community of Practice of the American Society of Transplantation review the diagnosis, prevention and management of blastomycosis, histoplasmosis, and coccidioidomycosis in the pre- and post-transplant period. Though each of these endemic fungal infections has unique epidemiology and clinical manifestations, they all share a predilection for primary pulmonary infection and may cause disseminated infection, particularly in immunocompromised hosts. Culture remains the gold standard for definitive diagnosis, but more rapid diagnosis may be achieved with direct visualization of organisms from clinical specimens and antigen-based enzyme immunoassay assays. Serology is of limited utility in transplant recipients. The mainstay of treatment for severe infections remains liposomal amphotericin followed by a step-down azole therapy. Cases of mild to moderate severity with no CNS involvement may be treated with azole therapy alone. The newer generation azoles provide additional treatment options, but supported currently with limited clinical efficacy data. Azole therapy in transplant recipients presents a unique challenge owing to the drug-drug interactions with immunosuppressant agents. Therapeutic drug monitoring of azole levels is an essential component of effective and safe therapy. Infection prevention centers around minimizing epidemiological exposures, early clinical recognition, and azole prophylaxis in selected individuals.

Epidemiology and Geographic Distribution of Blastomycosis, Histoplasmosis, and Coccidioidomycosis, Ontario, Canada, 1990-2015

Elevated incidence of blastomycosis in Ontario calls for diagnostic vigilance.

Endemic mycoses represent a growing public health challenge in North America. We describe the epidemiology of 1,392 microbiology laboratory–confirmed cases of blastomycosis, histoplasmosis, and coccidioidomycosis in Ontario during 1990–2015. Blastomycosis was the most common infection (1,092 cases; incidence of 0.41 cases/100,000 population), followed by histoplasmosis (211 cases) and coccidioidomycosis (89 cases). Incidence of blastomycosis increased from 1995 to 2001 and has remained elevated, especially in the northwest region, incorporating several localized hotspots where disease incidence (10.9 cases/100,000 population) is 12.6 times greater than in any other region of the province. This retrospective study substantially increases the number of known endemic fungal infections reported in Canada, confirms Ontario as an important region of endemicity for blastomycosis and histoplasmosis, and provides an epidemiologic baseline for future disease surveillance. Clinicians should include blastomycosis and histoplasmosis in the differential diagnosis of antibiotic-refractory pneumonia in patients traveling to or residing in Ontario.

Disseminated Blastomycosis in a Teenager Presenting with Pleural Effusion and Splenomegaly

BACKGROUND

Blastomycosis is caused by a fungus endemic to states and providences bordering the Lawrence Rivers and the Great Lakes. It can lead to significant pathology in both immunocompetent and immunocompromised hosts. This case report describes disseminated blastomycosis in an otherwise healthy 16-year-old patient.

CASE REPORT

A 16-year-old male presented with a chief complaint of flank pain. In the Emergency Department he described additional symptoms of emesis, cough, and weight loss. His vitals were appropriate; however, he had absent lung sounds in the left lower lung field, splenomegaly, a left thigh abscess, and lower-extremity edema. Imaging studies showed a left pleural effusion, mediastinal shift to the right, splenomegaly, a left psoas abscess, and undifferentiated bony involvement of L1 transverse process and the left 12th rib. Abscess cultures grew Blastomyces dermatitides. He was treated with amphotericin B, demonstrated clinical improvement, and was discharged on itraconazole. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: The case fatality rate of blastomycosis is estimated at between 4.3% and 6.4%. Patients with solid organ transplant and associated immune suppression had a mortality of 33-38%. Given the nonspecific nature of this condition, a high level of suspicion is required for diagnosis, and early diagnosis is essential, as end organ damage in disseminated disease can include high-severity illness, including acute respiratory distress syndrome and central nervous system dysfunction. If any patient presents with symptomatology involving both skin and pulmonary systems, blastomycosis must be entertained as a possible diagnosis. Prompt diagnosis and treatment will significantly improve morbidity and mortality.

Blastomycosis in Southern Saskatchewan 2000-2015: Unique presentations and disease characteristics

In the literature, cases of blastomycosis in Canada have been documented in provinces bordering the Great Lakes, including Ontario and Quebec, as well as Manitoba. This is the first study to our knowledge reporting cases of mycosis seen in southern Saskatchewan suggesting a broader area of endemicity. We searched the Regina Qu'Appelle Health Region (RQHR) Microbiology Laboratory for all culture-confirmed cases of Blastomyces from January 2000 to December 2015 and identified 15 cases. Thirteen cases were reviewed, identifying common presenting symptoms, misdiagnosis, comorbidities, travel history, time from presentation to diagnosis, diagnostic specimen, treatment, and clinical outcome. Nine patients had no travel to areas known to be endemic to environmental blastomycosis. Eight patients presented with respiratory symptoms, four with skin lesions, four with constitutional symptoms, and one presented with chest pain after a fall. Initial misdiagnosis occurred in nine (69%) of the 13 cases, and all six patients that died of the disease were misdiagnosed. These six patients (46%) were acutely ill with refractory disseminated disease, leading to respiratory failure. It is probable that Blastomyces is present as an endemic fungus in the soil of southern Saskatchewan. Possibly due to a lack of awareness of this pathogen in the area, initial misdiagnoses were common and likely contributed to significant morbidity and mortality.

Central nervous system blastomycosis diagnosed using the MVista® Blastomyces quantitative antigen enzyme immunoassay test on cerebrospinal fluid: A case report and review of the literature

Blastomyces dermatitidis is a thermally dimorphic fungus that is capable of causing pulmonary and extra-pulmonary disease, including infections of the central nervous system (CNS). Diagnosis of CNS blastomycosis with non-invasive testing can be difficult, and a surgical biopsy may ultimately be required for microbiological and/or histopathological confirmation. A case of B. dermatitidis meningitis is presented where the diagnosis was made by testing cerebrospinal fluid (CSF) using the MVista® Blastomyces Quantitative Antigen Enzyme Immunoassay test. The utility of performing this test on CSF for diagnosis of CNS mass lesions/abscesses caused by B. dermatitidis in the absence of associated meningitis remains unclear. Cross reaction of the Blastomyces antigen test with other dimorphic fungi is a concern, necessitating that positive test results are interpreted in the context of the patient's exposure and travel history.

Blastomycosis hospitalizations in northwestern Ontario: 2006-2015

BACKGROUND

Blastomycosis, caused by the organism Blastomyces dermatitidis, is an invasive fungal disease found in Central Canada and Central and Midwestern United States.

OBJECTIVE

To describe trends in and epidemiology of hospitalized cases of blastomycosis cases reported among northwestern Ontario residents between 2006 and 2015.

METHODS

Blastomycosis hospitalization data were extracted from the Discharge Abstract Database (DAD), accessed through IntelliHEALTH Ontario. The DAD includes administrative, clinical and demographic information on hospital discharges provided by the Canadian Institute for Health Information (CIHI). Blastomycosis records were identified using ICD-10 codes B40.0 to B40.9. Hospitalization rates were calculated for all of Ontario, and age-specific hospitalization rates were calculated for northwestern Ontario and analyzed by local health region, time and seasonality as well as presenting symptoms.

RESULTS

There were 581 hospitalizations for blastomycosis reported in Ontario over this 10-year period. Of these, 245 (42%) were from northwestern Ontario, although this region accounts for only 0.6% of the Ontario population. The average hospitalization rate for blastomycosis in northwestern Ontario was 35.0 per 100,000 per year. This rate varied from 1.7 in the Red Lake region to 57.9 in the Kenora region. The most common presentation was acute pulmonary symptoms. Men were 1.36 times more likely to be hospitalized for blastomycosis than were women (95% confidence interval [CI]: 1.06-1.75, P<0.05). Most hospitalizations were registered in the late fall months, suggesting blastomycosis exposure in the spring/summer season followed by a lengthy incubation period.

CONCLUSION

Areas of northwestern Ontario have high reported rates of blastomycosis. It is not known to what extent there are regional differences in other states and provinces. Interregional differences may warrant prioritizing strategies for blastomycosis prevention and control as well as additional research and surveillance.

Central Nervous System Blastomycosis in Children: A Case Report and Review of the Literature

We present a 7-year-old boy with chronic meningitis caused by Blastomyces dermatitidis. A review of the literature revealed 32 cases of central nervous system blastomycosis in children between 1983 and 2016, of which 18 represented parenchymal disease of the brain or spinal cord. Blastomycosis affecting the central nervous system is rare but should be considered in children with chronic meningitis.

Clinical Manifestations and Treatment of Blastomycosis

The causal agents of blastomycosis, Blastomyces dermatitidis and Blastomyces gilchristii, belong to a group of thermally dimorphic fungi that can infect healthy and immunocompromised individuals. Following inhalation of mycelial fragments and spores into the lungs, Blastomyces spp convert into pathogenic yeast and evade host immune defenses to cause pneumonia and disseminated disease. The clinical spectrum of pulmonary blastomycosis is diverse. The diagnosis of blastomycosis requires a high degree of clinical suspicion and involves culture-based and non-culture-based fungal diagnostic tests. The site and severity of infection, and the presence of underlying immunosuppression or pregnancy, influence the selection of antifungal therapy.

Probable pulmonary Blastomyomycocis in an immunocompetent person

The current case report presents a 29-year old man who worked as a hotel guard in a city in China. The patient had fever and dry cough before and after hospitalization. Chest X-ray and CT revealed nodular and patchy lesions in both lower lungs. There were no abnormal findings in the examination of sputum and bronchoalveoular lavage fluid (BALF). He was diagnosed with pulmonary blastomycosis by histological examination of lung biopsy and treated with fluconazole. Follow-up chest CT examination demonstrated that the patient was recovered through appropriate antifungal treatment.

Blastomycosis in Children: An Analysis of Clinical, Epidemiologic, and Genetic Features

BACKGROUND

Blastomyces spp. are endemic in regions of the United States and result in blastomycosis, a serious and potentially fatal infection. Little is known about the presentation, clinic course, epidemiology, and genetics of blastomycosis in children.

METHODS

A retrospective review of children with blastomycosis confirmed by culture or cytopathology between 1999 and 2014 was completed. Blastomyces sp. isolates were genotyped by using microsatellite typing, and species were typed by sequencing of internal transcribed spacer 2 (its2).

RESULTS

Of the 114 children with blastomycosis identified, 79% had isolated pulmonary involvement and 21% had extrapulmonary disease. There were more systemic findings, including fever (P = .01), poor intake (P = .01), elevated white blood cell count (P < .01), and elevated C-reactive protein level (P < .01), in children with isolated pulmonary disease than in children with extrapulmonary disease. Children with extrapulmonary disease had more surgeries (P = .01) and delays in diagnosis (P < .01) than those with isolated pulmonary infection. Of 52 samples genotyped, 48 (92%) were Blastomyces gilchristii and 4 (8%) were Blastomyces dermatitidis.

CONCLUSION

This is the first large-scale study of the clinical, epidemiologic, and genetic features of blastomycosis in children. The majority of the children had isolated pulmonary disease with systemic findings. Patients with extrapulmonary disease were less likely to have systemic symptoms or additional laboratory evidence of infection, which made delays in diagnosis more common. More than 90% of the pediatric cases were caused by B gilchristii.

Blastomycosis during pregnancy: a case report and review of the literature

The diagnosis of blastomycosis during pregnancy is rare, but can carry significant clinical questions for both the infected mother and developing fetus. Furthermore, given its rarity, providers have little available data to help manage and counsel patients in this uncommon, yet serious, scenario. We present a case of blastomycosis in a woman at 38weeks' gestation and review all published cases of blastomycosis during pregnancy. It is our hope to provide a multidisciplinary understanding of the current knowledge surrounding the presentation, diagnosis, management, and outcome of this unusual infection.

Management and Outcomes of Acute Respiratory Distress Syndrome Caused by Blastomycosis: A Retrospective Case Series

Acute respiratory distress syndrome (ARDS) is an uncommon, highly fatal, and poorly understood manifestation of blastomycosis. Optimal management remains unknown, including the roles of adjunctive corticosteroids and extracorporeal membrane oxygenation (ECMO).We conducted a retrospective chart review of patients with ARDS caused by blastomycosis, managed in intensive care units in Manitoba, Canada, from 1992 to 2014. ARDS was defined using the Berlin definition. Corticosteroid therapy was defined as ≥150 mg cortisol equivalent in 24 hours. Logistic regression was used to identify determinants of a fatal outcome, and bootstrap resampling was used to assess sample size requirements.Forty-three patients with ARDS caused by blastomycosis were identified. ARDS was mild, moderate, and severe in 2 (5%), 12 (28%), and 29 (67%) patients, respectively. Management included amphotericin B (n = 42, 98%), vasopressors (n = 36, 84%), corticosteroids (n = 22, 51%), renal replacement (n = 13, 30%), and ECMO (n = 4, 11%). Seventeen patients (40%) died. All patients treated with ECMO survived (P = 0.14). Corticosteroids were not associated with survival benefit in univariate (P = 0.43) or multivariate analyses (odds ratio 0.52, 95% confidence interval 0.11-2.34). Bootstrap studies indicated that almost 500 patients would be needed to confirm a significant reduction in mortality from corticosteroids (type I error = 0.05, power = 80%).Blastomycosis is an uncommon, albeit important, cause of ARDS in this geographic area. Given the rarity of disease and the large cohort needed to demonstrate mortality benefit, the role of adjunctive therapies, including corticosteroids and ECMO, may remain unconfirmed, and clinical judgment should guide management decisions.

Endemic Mycoses: What's New About Old Diseases?

Infections with geographically constrained dimorphic fungi cause the endemic mycoses, which include blastomycosis, coccidioidomycosis, emmonsiosis, histoplasmosis, paracoccidioidomycosis, sporotrichosis, and penicilliosis. In the last 5 years, our understanding of the epidemiology, diagnostics, and to a lesser extent management of these diseases has advanced. Specifically, the application of molecular techniques for genotyping fungal pathogens has resulted in the recognition of cryptic species within several genera, including Blastomyces, and Paracoccidioides; the reclassification of Penicillium marneffei, the agent of penicilliosis, to the genus Talaromyces; and the global emergence of dimorphic fungi of the genus Emmonsia, cause disease in immunocompromised persons. New and refined diagnostic tests are available based on the detection of circulating antigens and antibodies, mass spectrometry, and targeted gene amplification. In contrast, the development of new therapeutic options remains stalled, although isavuconazole may hold promise. Finally, advances have been made in the prospect of viable vaccines for preventing animal and human disease.

Blastomycosis

Blastomycosis is an endemic fungal infection due to Blastomyces dermatitidis that most commonly causes pneumonia; but the organism can disseminate to any organ system, most commonly the skin, bones/joints, and genitourinary tract. Both immunocompetent and immunocompromised persons can be infected, but more severe disease occurs in the immunocompromised. Blastomycosis can be diagnosed by culture, direct visualization of the yeast in affected tissue, and/or antigen testing. Treatment course and duration depend on severity of illness. For mild to moderate pulmonary disease the treatment is itraconazole. For severe blastomycosis, lipid formulation amphotericin B is given, followed by step-down therapy with itraconazole.

Blastomyces Antigen Detection for Diagnosis and Management of Blastomycosis

Blastomyces spp. antigen testing was evaluated over a 10-year period in an area where blastomycosis is endemic. Antigen testing was less sensitive than previously reported, but serial urine testing was useful in monitoring disease resolution or progression. Culture and cytopathology remain the gold standard for diagnosis and exclusion of this infection.

Blastomycosis in northwestern Ontario, 2004 to 2014

Blastomycosis is an invasive fungal disease caused by Blastomyces dermatitidis and the recently discovered Blastomyces gilchristii. The medical charts of 64 patients with confirmed cases of blastomycosis in northwestern Ontario during a 10-year period (2004 to 2014) were retrospectively reviewed. The number of patients diagnosed with blastomycosis in Ontario was observed to have increased substantially compared with before 1990, when blastomycosis was removed from the list of reportable diseases. Aboriginals were observed to be disproportionately represented in the patient population. Of the patients whose smoking status was known, 71.4% had a history of smoking. 59.4% of patients had underlying comorbidities and a higher comorbidity rate was observed among Aboriginal patients. The case-fatality rate from direct complications of blastomycosis disease was calculated to be 20.3%; this case-fatality rate is the highest ever to be reported in Canada and more than double that of previously published Canadian studies. The clinical characteristics of 64 patients diagnosed with blastomycosis are summarized.

Histoplasmosis and Blastomycosis in Solid Organ Transplant Recipients

Histoplasmosis and blastomycosis are geographically restricted dimorphic fungi that cause infection after the conidia produced in the mold phase are inhaled into the lungs. In the lungs, at 37 °C, these organisms undergo transformation into the yeast phase. In transplant recipients, infection can occur by exposure to the mold in the environment, by reactivation of infection that had occurred previously and had been controlled by the host until immunosuppressive medications were given post-transplantation, and finally by transmission from the donor organ in the case of histoplasmosis. In transplant recipients, disseminated infection is common, and pulmonary infection is more likely to be severe than in a non-immunosuppressed person. Diagnosis has been improved, allowing earlier treatment, with the use of rapid antigen tests performed on serum and urine. Initial treatment, for all but the mildest cases of acute pulmonary histoplasmosis, should be with a lipid formulation of amphotericin B. After clinical improvement has occurred, step-down therapy with itraconazole is recommended for a total of 12 months for most transplant recipients, but some patients will require long-term suppressive therapy to prevent relapse of disease.

Blastomycosis mortality rates, United States, 1990-2010

Risks for illness and death caused by the Blastomyces dermatitidis fungus are affected by demographic, geographic, and behavioral factors.

Blastomycosis is a potentially fatal fungal infection endemic to parts of North America. We used national multiple-cause-of-death data and census population estimates for 1990–2010 to calculate age-adjusted mortality rates and rate ratios (RRs). We modeled trends over time using Poisson regression. Death occurred more often among older persons (RR 2.11, 95% confidence limit [CL] 1.76, 2.53 for those 75–84 years of age vs. 55–64 years), men (RR 2.43, 95% CL 2.19, 2.70), Native Americans (RR 4.13, 95% CL 3.86, 4.42 vs. whites), and blacks (RR 1.86, 95% CL 1.73, 2.01 vs. whites), in notably younger persons of Asian origin (mean = 41.6 years vs. 64.2 years for whites); and in the South (RR 18.15, 95% CL 11.63, 28.34 vs. West) and Midwest (RR 23.10, 95% CL14.78, 36.12 vs. West). In regions where blastomycosis is endemic, we recommend that the diagnosis be considered in patients with pulmonary disease and that it be a reportable disease.

Extracorporeal membrane oxygenation for blastomycosis-related acute respiratory distress syndrome: a case series

PURPOSE

Blastomyces dermatitidis is a dimorphic fungus endemic to North America capable of causing fatal respiratory failure. Acute respiratory distress syndrome (ARDS) complicates up to 10% of pulmonary blastomycosis in hospitalized patients and carries a mortality of 50-90%. This report describes the clinical course of four consecutive patients with blastomycosis-related ARDS treated with venovenous extracorporeal membrane oxygenation (ECMO) during 2009-2014.

CLINICAL FEATURES

Four adults were referred from northwestern Ontario, Canada with progressive respiratory illnesses. All patients developed diffuse bilateral opacities on chest radiography and required mechanical ventilation within 6-72 hr. Patients satisfied Berlin criteria for severe ARDS with trough PaO2/F i O2 ratios of 44-61 on positive end-expiratory pressure of 12-24 cm H2O. Wet mount microscopy from respiratory samples showed broad-based yeast consistent with B.dermatitidis. Despite lung protective ventilation strategies with maximal F i O2 (patients A-D), neuromuscular blockade (patients A-D), inhaled nitric oxide (patients A and D), and prone positioning (patient D), progressive hypoxemia resulted in initiation of venovenous ECMO by hours 24-90 of mechanical ventilation with subsequent de-escalation of ventilatory support. In all four cases, ECMO decannulation was performed (7-23 days), mechanical ventilation was withdrawn (18-52 days), and the patients survived to hospital discharge (31-87 days).

CONCLUSION

This report describes the successful application of ECMO as rescue therapy in aid of four patients with refractory blastomycosis-associated ARDS. In addition to early appropriate antimicrobial therapy, transfer to an institution experienced with ECMO should be considered when caring for patients from endemic areas with rapidly progressive respiratory failure.

Thermally Dimorphic Human Fungal Pathogens--Polyphyletic Pathogens with a Convergent Pathogenicity Trait

Fungi are adept at changing their cell shape and developmental program in response to signals in their surroundings. Here we focus on a group of evolutionarily related fungal pathogens of humans known as the thermally dimorphic fungi. These organisms grow in a hyphal form in the environment but shift their morphology drastically within a mammalian host. Temperature is one of the main host signals that initiates their conversion to the "host" form and is sufficient in the laboratory to trigger establishment of this host-adapted developmental program. Here we discuss the major human pathogens in this group, which are Blastomyces dermatiditis, Coccidioides immitis/posadasii, Histoplasma capsulatum, Paracoccidioides brasiliensis/lutzii, Sporothrix schenckii, and Talaromyces marneffei (formerly known as Penicillium marneffei). The majority of these organisms are primary pathogens, with the ability to cause disease in healthy humans who encounter them in endemic areas.

Unexpected Blastomyces dermatitidis etiology of fungal sinusitis and erosive palatal infection in a diabetic patient

We present what is believed to be the initial report of hard-palate infection caused by Blastomyces dermatitidis. The organism was cultivated from biopsy material obtained from a diabetic patient presenting with complaints of headache and malaise. Radiologic findings revealed a malignant-appearing soft-tissue mass with paranasal sinus base destruction.

Blastomycosis in Children: A Study of 14 Cases

We retrospectively reviewed 14 children with active blastomycosis. Pulmonary disease occurred in 86% of the cohort and extrapulmonary dissemination was noted in 46%. Urine blastomycosis or histoplasmosis antigens were positive in all tested patients. Acute kidney injury was common in patients who were treated with amphotericin. Mortality tended to be associated with a delay in diagnosis.

Endemic fungal infections in inflammatory bowel disease associated with anti-TNF antibody therapy

Patients with inflammatory bowel disease are susceptible to complications from pharmacologic treatment of their disease. Tumor necrosis factor (TNF)-α inhibitors are being used increasingly in the treatment of inflammatory bowel disease and can be associated with adverse events, including common infections, and rarely the development of serious life-threatening opportunistic infections. TNF-α inhibitors have the ability to prevent an effective patient granulomatous response, and this may be associated with an increased risk of developing mycobacterial and certain fungal infections, including histoplasmosis, blastomycosis, and coccidioidomycosis, endemic in several parts of the United States. The concern for invasive fungal infection was realized during clinical trials and further demonstrated after the marketing of TNF-α inhibitors. Because of this awareness, the Food and Drug Administration developed an adverse event-reporting system to capture cases of infections associated with the use of TNF-α inhibitors. These opportunistic fungi have a great degree of regional variability, and it has been very difficult to quantify the incidence of infection in patients treated with TNF-α inhibitors. Currently, there are no formal guidelines regarding the use of TNF-α inhibitors and these fungal infections. Considering that gastroenterologists have embraced the use TNF-α inhibitors as a valuable armamentarium in the treatment of inflammatory bowel disease, they must be aware of therapy-related infectious complications, including appropriate diagnostic, therapeutic, and preventive strategies. In this article, we explore the association of these fungal entities in relation to the TNF-α inhibitor therapy by considering information provided in the gastroenterology, infectious diseases, rheumatology, and transplant literature. Finally, we provide some recommendations on diagnosis and treatment.