Epidemiological and clinical features of a large blastomycosis outbreak at a paper mill in Michigan.

BACKGROUND: Blastomycosis is an environmentally acquired fungal infection that can result in severe pulmonary illness and high hospitalization rates. In 2023, a blastomycosis outbreak was detected among workers at a paper mill in Delta County, Michigan. METHODS: We included patients with clinical and laboratory evidence of blastomycosis who had spent ≥40 hours in Delta County since September 1, 2022 and had illness onset December 1, 2022-July 1, 2023. We assessed epidemiological and clinical features of patients and evaluated factors associated with hospitalization. We performed whole-genome sequencing to characterize genetic relatedness of clinical isolates from eight patients. RESULTS: In total, 131 patients were identified; all had worked at or visited the mill. Sixteen patients (12%) were hospitalized; one died. Compared with non-hospitalized patients, more hospitalized patients had diabetes (p=0.03) and urine antigen titers above the lower limit of quantification (p<0.001). Hospitalized patients were also more likely to have had ≥1 healthcare visits before receiving a blastomycosis diagnostic test (p=0.02) and to have been treated with antibiotics prior to antifungal prescription (p=0.001). All sequenced isolates were identified as Blastomyces gilchristii and clustered into a distinct outbreak cluster. CONCLUSIONS: This was the largest documented blastomycosis outbreak in the United States. Epidemiologic evidence indicated exposures occurred at or near the mill, and genomic findings suggested a common exposure source. Patients with diabetes may have increased risk for hospitalization, and elevated urine antigen titers could indicate greater disease severity. Early suspicion of blastomycosis may prompt earlier diagnosis and treatment, potentially reducing unnecessary antibiotic prescriptions and improving patient outcomes.

Genomic Epidemiology of Large Blastomycosis Outbreak, Ontario, Canada, 2021.

Using phylogenomic analysis, we provide genomic epidemiology analysis of a large blastomycosis outbreak in Ontario, Canada, caused by Blastomyces gilchristii. The outbreak occurred in a locale where blastomycosis is rarely diagnosed, signaling a possible shift in geographically associated incidence patterns. Results elucidated fungal population genetic structure, enhancing understanding of the outbreak.

Using Insurance Claims Data to Estimate Blastomycosis Incidence, Vermont, USA, 2011-2020.

The epidemiology of blastomycosis in Vermont, USA, is poorly understood. Using insurance claims data, we estimated the mean annual blastomycosis incidence was 1.8 patients/100,000 persons during 2011-2020. Incidence and disease severity were highest in north-central counties. Our findings highlight a need for improved clinical awareness and expanded surveillance.

Disseminated Blastomycosis in an Immunocompetent Patient.

Blastomycoses dermatitidis is a dimorphic fungus that can cause disseminated blastomycosis with varying clinical manifestations and multiorgan involvement. While blastomycosis commonly causes pulmonary disease, extrapulmonary spread can result in skin, bone, and central nervous system involvement. Cutaneous blastomycosis can present as pustular lesions that evolve into ulcerative or verrucous plaques. We present a case of disseminated blastomycosis in an immunocompetent patient with both pulmonary and cutaneous features. The patient developed hypoxic respiratory failure and was subsequently diagnosed with disseminated blastomycosis after undergoing bronchoscopy with bronchial washing. He was found to have ulcerative nasal lesions as part of his disseminated disease. He was successfully treated with amphotericin B and ultimately discharged from the hospital.

Detection of Blastomyces gilchristii via metagenomic sequencing in outbreak-associated soils.

Cases of blastomycosis, a serious fungal disease globally rare but endemic to North America, can appear both sporadically and in outbreaks. Tracing these outbreaks to their environment has traditionally used culturing and polymerase chain reaction. Here, we present our method for metagenomic detection of Blastomyces in a 2015 outbreak soil sample from central Wisconsin. By sequencing this sample to multiple depths, we simulated the minimum required depth to detect Blastomyces in this outbreak. Our methods and recommendations can be used to identify the sources of blastomycosis during outbreaks and to learn about the ecology of Blastomyces.

Proceedings of the second international meeting on endemic mycoses of the Americas (IMEMA) and first international symposium on implantation mycoses (ISIM).

The second international meeting on endemic mycoses of the Americas (IMEMA) and the first international symposium on implantation mycoses (ISIM) took place in Santiago del Estero, Argentina, on September 25-27, 2023. The conference provided a platform for researchers, clinicians, and experts to discuss the latest developments in the field of endemic and implantation mycoses. Topics included epidemiology, diagnostic advances, treatment strategies, and the impact of environmental factors on the spread of these fungal diseases. IMEMA and ISIM contributed to the regional discourse on the mycoses, emphasizing the importance of international cooperation in addressing these public health challenges.

IMEMA/ISIM, held in Santiago del Estero, Argentina, convened experts to discuss endemic and implantation mycoses, covering topics such as epidemiology, diagnostics, treatment, and advocacy. The event highlighted ongoing efforts in combating these diseases.

Exome Sequencing of a Blastomycosis Case-Control Cohort From Manitoba and Northwestern Ontario, Canada.

BACKGROUND: Blastomycosis is a pulmonary disease caused by Blastomyces spp., a group of pathogenic dimorphic fungi endemic to a number of geographic regions, specifically Manitoba and northwestern Ontario, Canada. Immunosuppression is a major risk factor affecting disease susceptibility, yet host immunity is not well understood. Genetic immunodeficiencies can also influence disease, with variants in IL6, GATA2 and VDBP shown to influence susceptibility. Additional genetic factors in disease susceptibility and severity remain undetected. Our study seeks to identify potential genetic risk factors in a blastomycosis case-control cohort from Manitoba and northwestern Ontario, Canada. METHODS: Exomes from 18 blastomycosis cases and 9 controls were sequenced, variants were identified and filtered for accuracy and quality. We performed candidate gene prioritisation and variant aggregation to identify genetic associations and explored the full exome dataset. RESULTS: Ninety-nine genetic variants in 42 candidate genes were identified in the exome dataset. No variants associated with susceptibility were identified in a single-variant analysis although two non-synonymous variants in TYK2 were enriched among cases suggesting a possible role in susceptibility. Gene-based association analysis found variants in TLR1 enriched in controls (p = 0.024) suggesting a possible protective effect. Gene cluster analysis identified genetic variants in genes of chromatin remodelling, proteasome and intraflagellar transport significantly enriched in cases (false discovery rates < 14%). CONCLUSIONS: The findings in this study show novel associations with blastomycosis susceptibility. A better understanding of host immunity and genetic predisposition to Blastomyces infection can help to inform clinical practice for improved outcomes.

Clinical Presentation of Blastomycosis is Associated With Infecting Species, Not Host Genotype.

Objective: To determine if host genetics may be a risk factor for severe blastomycosis.Design: A cohort of patients who had contracted blastomycosis underwent targeted SNP (single nucleotide polymorphism) genotyping. The genetics of these patients were compared to a set of age and gender-matched controls and between patients with severe versus mild to moderate blastomycosis.Setting: The Marshfield Clinic Health System in central and northern WisconsinParticipants: Patients with a diagnosis of blastomycosis prior to 2017 were contacted for enrollment in this study. A phone hotline was also set up to allow interested participants from outside the Marshfield Clinic Health System to request enrollment.Methods: SNP frequency was assessed for significant differences between the patient cohort and controls and between patients with severe versus mild to moderate blastomycosis. We also tested the effect of Blastomyces species identified in clinical isolates on disease symptoms and severity.Results: No significant differences were found in SNP frequency between cases and controls or between those with severe or mild to moderate blastomycosis. We did detect significant differences in symptom frequency and disease severity by Blastomyces species.Conclusions: Our study did not identify any genetic risk factors for blastomycosis. Instead, the species of Blastomyces causing the infection had a significant effect on disease severity.

Clinical Testing Guidance for Coccidioidomycosis, Histoplasmosis, and Blastomycosis in Patients with Community-Acquired Pneumonia for Primary and Urgent Care Providers.

Coccidioidomycosis, histoplasmosis, and blastomycosis are underrecognized and frequently misdiagnosed fungal infections that can clinically resemble bacterial and viral community-acquired pneumonia (CAP). This guidance is intended to help clinicians in outpatient settings test for these fungal diseases in patients with CAP to reduce misdiagnoses, unnecessary antibacterial use, and poor outcomes.

The Geographic Distribution of Dimorphic Mycoses in the United States for the Modern Era.

BACKGROUND: The dimorphic mycoses (DMs) of the United States-Histoplasma, Coccidioides, and Blastomyces-commonly known as endemic mycoses of North America (in addition to Paracoccidioides) are increasingly being diagnosed outside their historical areas of endemicity. Despite this trend, the maps outlining their geographic distributions have not been updated in more than half a century using a large, nationwide database containing individual-patient-level data. METHODS: This was a retrospective analysis of >45 million Medicare fee-for-service beneficiaries from 1 January 2007 through 31 December 2016. Diagnoses of histoplasmosis, coccidioidomycosis, and blastomycosis were defined by International Classification of Diseases, Ninth/10th Revision, codes. The primary outcome was the incidence of histoplasmosis, coccidioidomycosis, and blastomycosis for each US county. Clinically meaningful thresholds for incidence were defined as 100 cases/100 000 person-years for histoplasmosis and coccidioidomycosis and 50 cases/100 000 person-years for blastomycosis. RESULTS: There were 79 749 histoplasmosis, 37 726 coccidioidomycosis, and 6109 blastomycosis diagnoses in unique persons from 2007-2016 across 3143 US counties. Considering all US states plus Washington, DC, 94% (48/51) had ≥1 county above the clinically relevant threshold for histoplasmosis, 69% (35/51) for coccidioidomycosis, and 78% (40/51) for blastomycosis. CONCLUSIONS: Persons with histoplasmosis, coccidioidomycosis, and blastomycosis are diagnosed in significant numbers outside their historical geographic distributions established >50 years ago. Clinicians should consider DM diagnoses based on compatible clinical syndromes with less emphasis placed on patients' geographic exposure. Increased clinical suspicion leading to a subsequent increase in DM diagnostic testing would likely result in fewer missed diagnoses, fewer diagnostic delays, and improved patient outcomes.

Increased Hospitalizations Involving Fungal Infections during COVID-19 Pandemic, United States, January 2020-December 2021.

Hospitalizations involving fungal infections increased 8.5% each year in the United States during 2019-2021. During 2020-2021, patients hospitalized with COVID-19-associated fungal infections had higher (48.5%) in-hospital mortality rates than those with non-COVID-19-associated fungal infections (12.3%). Improved fungal disease surveillance is needed, particularly during respiratory virus pandemics.

In vitro manogepix susceptibility testing of South African Emergomyces africanus, Emergomyces pasteurianus, and Blastomyces emzantsi clinical isolates.

We performed in vitro antifungal susceptibility testing of manogepix against the yeast phase of 78 Emergomyces africanus, 2 Emergomyces pasteurianus, and 5 Blastomyces emzantsi isolates using a reference broth microdilution method following Clinical and Laboratory Standards Institute recommendations. All three pathogens had low minimum inhibitory concentrations ranging from <0.0005 to 0.008 mg/L. Manogepix should be investigated in animal models and potentially in future human clinical trials for endemic mycoses.

The Billirud Mill Blastomycosis Outbreak: Comparison to Historical Controls.

A large outbreak of blastomycosis among paper mill workers in Escanaba, Michigan began with the first cases reported on February 28, 2023 and expanded to 120 cases. Analysis of baseline regional data and the data collected during this unprecedented outbreak provide insight on the outbreak's unique characteristics. The Michigan Disease Surveillance System provided descriptive and outcome data on blastomycosis cases in the Upper Peninsula from 2007 through 2022 and the 2023 outbreak. Baseline incidence for the region was estimated and outbreak cases were compared to historic controls using quantitative methods such as t-tests, chi-square, and Poisson and logistic regression. The Billirud blastomycosis outbreak has resulted in 28 confirmed and 92 probable cases. Blastomycosis incidence for the Upper Peninsula was 2.13 (95%CI: 1.75, 2.59) per 100,000 person-years with counties bordering Wisconsin having a higher incidence more than other counties (4.56, 95%CI: 3.48, 5.97; RR=3.46, 95%CI: 2.35, 5.11). Outbreak cases were significantly younger, more likely to be male, reported more respiratory symptoms, and had a shorter time from onset of illness to diagnosis. The Billirud paper mill blastomycosis outbreak is the largest reported to date, the first in an industrial facility, and the first to specifically involve Blastomyces gilchristii. Blastomyces species are endemic in regional forests, so other facilities handling forestry products may be at risk.

The characteristics of the cases from the largest outbreak of blastomycosis in North America are compared to sporadic cases from the same region over the previous 16 years. The outbreak cases were younger, more likely to be male, and reported more respiratory difficulties.

Diagnostic delay in pulmonary blastomycosis: a case series reflecting a referral center experience.

PURPOSE: The diagnosis of pulmonary blastomycosis is usually delayed because of its non-specific presentation. We aimed to assess the extent of diagnostic delay in hospitalized patients and detect the step in the diagnostic process that requires the most improvement. METHODS: Adult patients diagnosed with pulmonary blastomycosis during a hospital admission between January 2010 through November 2021 were eligible for inclusion. Patients who did not have pulmonary involvement and who were diagnosed before admission were excluded. Demographics and comorbid conditions, specifics of disease presentation, and interventions were evaluated. The timing of the diagnosis, antifungal treatment, and patient outcomes were noted. Descriptive analytical tests were performed. RESULTS: A total of 43 patients were diagnosed with pulmonary blastomycosis during their admissions. The median age was 47 years, with 13 (30%) females. Of all patients, 29 (67%) had isolated pulmonary infection, while 14 (33%) had disseminated disease, affecting mostly skin and musculoskeletal system. The median duration between the initial symptoms and health care encounters was 4 days, and the time to hospital admission was 9 days. The median duration from the initial symptoms to the diagnosis was 20 days. Forty patients (93%) were treated with empirical antibacterials before a definitive diagnosis was made. In addition, corticosteroid treatment was empirically administered to 15 patients (35%) before the diagnosis, with indications such as suspicion of inflammatory processes or symptom relief. In 38 patients (88%), the first performed fungal diagnostic test was positive. Nineteen patients (44%) required admission to the intensive care unit, and 11 patients (26%) died during their hospital stay. CONCLUSION: There was a delay in diagnosis of patients with pulmonary blastomycosis, largely attributable to the lack of consideration of the etiological agent. Novel approaches to assist providers in recognizing the illness earlier and trigger evaluation are needed.

First Japanese case of disseminated blastomycosis imported from North America: A case report.

Blastomycosis is a fungal infectious disease that can occur in both immunocompromised and immunocompetent populations endemic in North America, with no previous reports in Japan. A 26-year-old Japanese female patient with no relevant medical history presented intermittent left back pain and an abnormal shadow in the left upper lung field eight months ago at a local clinic. She was referred to our hospital for further evaluation and treatment. The patient currently lives in Japan, but until two years ago had spent several years in New York, Vermont and California. Chest computed tomography revealed a 30 mm mass with a cavity in the left pulmonary apex. The specimens obtained by transbronchial biopsy showed periodic acid-Schiff stain (PAS)-positive and Grocott-positive yeast-like fungi scattered among the granulomas, with no malignant findings, and the initial pathology did not lead to a definitive diagnosis. She was empirically started on fluconazole because of onset of multiple subcutaneous abscesses and was referred to the Medical Mycology Research Center. Although antibody tests could not diagnose the disease, blastomycosis was suspected based on the pathology of the skin and lung tissue at the Medical Mycology Research Center, and Blastomyces dermatitidis was identified by ITS analysis of the rRNA region. Her symptoms and CT findings gradually improved with fluconazole. We reported the first Japanese case of blastomycosis with pulmonary and cutaneous involvement in Japan. As the number of overseas travelers is expected to continue increasing, we would like to emphasize the importance of travel history interviews and information of blastomycosis.

Does metabolite matter? Defining target itraconazole and hydroxy-itraconazole serum concentrations for blastomycosis.

BACKGROUND: Itraconazole is the recommended first-line treatment for mild-to-moderate blastomycosis and consolidation treatment of moderate-to-severe disease. Itraconazole is metabolised into three metabolites, including an active metabolite hydroxy-itraconazole. Literature provides little evidence indicating whether therapeutic drug monitoring targets should be based on itraconazole parent compound alone or a sum of itraconazole and hydroxy-itraconazole serum concentrations. OBJECTIVES: This study aims to compare clinical outcomes and adverse drug events (ADEs) of combined itraconazole and hydroxy-itraconazole concentrations versus itraconazole parent compound alone in patients with blastomycosis. PATIENTS/METHODS: This study was a retrospective cohort review of patients ≥18 years with probable or proven Blastomyces infection who received itraconazole with at least one documented serum itraconazole concentration. The primary outcome was rate of partial or complete treatment response across three patient groups: (1) Itraconazole parent compound >1.0 mcg/ml (parent), (2) parent compound <1.0 mcg/ml, but a combined itraconazole and hydroxy-itraconazole >1.0 mcg/ml (combined) and (3) failure to achieve a combined or parent concentration >1.0 mcg/ml (subtherapeutic) for >75% of the duration of itraconazole therapy. RESULTS: A total of 80 patients were included (parent = 32, combined = 36, subtherapeutic = 12). No statistically significant difference was observed for rate of partial or complete treatment response (97% parent vs 94% combined, p = .99). Significantly higher mortality due to blastomycosis was observed in patients in the subtherapeutic group (0% parent vs 3% combined vs 25% subtherapeutic, p = .01). CONCLUSIONS: This study supports an itraconazole therapeutic target combining itraconazole and hydroxy-itraconazole >1.0 mcg/ml for blastomycosis treatment.

Scrotal abscess as an unusual presentation of blastomycosis.

Blastomyces dermatitidis is an environmental fungus endemic to parts of Eastern North America that notably causes pulmonary infection in humans and other animals with the potential for extrapulmonary spread, particularly in immunocompromised hosts. However, it rarely presents with genitourinary (GU) tract involvement. Herein, we present a unique case of a 37-year-old immunocompetent male with genitourinary blastomycosis with the initial presentation of a scrotal abscess.

Disseminated Blastomycosis in an African American immunocompetent pediatric patient: Lessons learned.

Disseminated blastomycosis can be challenging to diagnose given possible involvement of nearly any extrapulmonary organ system and the limitations of fungal diagnostic testing. Certain racial groups are at increased risk of disseminated fungal infections, even in immunocompetent patients. We describe a case of disseminated blastomycosis with cutaneous involvement in an African American adolescent with delayed diagnosis. Dermatologists can play an important role in the timely diagnosis of this disease entity by performing appropriate cutaneous biopsy techniques and should be involved early in these cases.

Endemic mycoses in children in North America: a review of radiologic findings.

Clinically significant endemic mycoses (fungal infections) in the United States (U.S.) include Blastomyces dermatitidis, Histoplasma capsulatum, and Coccidioides immitis/posadasii. While the majority of infections go clinically unnoticed, symptomatic disease can occur in immunocompromised or hospitalized patients, and occasionally in immune-competent individuals. Clinical manifestations vary widely and their diagnosis may require fungal culture, making the rapid diagnosis a challenge. Imaging can be helpful in making a clinical diagnosis prior to laboratory confirmation, as well as assist in characterizing disease extent and severity. In this review, we discuss the three major endemic fungal infections that occur in the U.S., including mycology, epidemiology, clinical presentations, and typical imaging features with an emphasis on the pediatric population.

Endemic Systemic Mycoses in Italy: A Systematic Review of Literature and a Practical Update.

Endemic systemic mycoses such as blastomycosis, coccidioidomycosis, histoplasmosis, talaromycosis, paracoccidioidomycosis are emerging as an important cause of morbidity and mortality worldwide. We conducted a systematic review on endemic systemic mycoses reported in Italy from 1914 to nowadays. We found out: 105 cases of histoplasmosis, 15 of paracoccidioidomycosis, 10 of coccidioidomycosis, 10 of blastomycosis and 3 of talaromycosis. Most cases have been reported in returning travelers and expatriates or immigrants. Thirtytwo patients did not have a story of traveling to an endemic area. Fortysix subjects had HIV/AIDS. Immunosuppression was the major risk factor for getting these infections and for severe outcomes. We provided an overview on microbiological characteristics and clinical management principles of systemic endemic mycoses with a focus on the cases reported in Italy.