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

Tracing histoplasmosis genomic epidemiology and species occurrence across the USA

ABSTRACTHistoplasmosis is an endemic mycosis in North America frequently reported along the Ohio and Mississippi River Valleys, although autochthonous cases occur in non-endemic areas. In the United States, the disease is provoked by two genetically distinct clades of Histoplasma capsulatum sensu lato, Histoplasma mississippiense (Nam1) and H. ohiense (Nam2). To bridge the molecular epidemiological gap, we genotyped 93 Histoplasma isolates (62 novel genomes) including clinical, environmental, and veterinarian samples from a broader geographical range by whole-genome sequencing, followed by evolutionary and species niche modelling analyses. We show that histoplasmosis is caused by two major lineages, H. ohiense and H. mississippiense; with sporadic cases caused by H. suramericanum in California and Texas. While H. ohiense is prevalent in eastern states, H. mississipiense was found to be prevalent in the central and western portions of the United States, but also geographically overlapping in some areas suggesting that these species might co-occur. Species Niche Modelling revealed that H. ohiense thrives in places with warmer and drier conditions, while H. mississippiense is endemic to areas with cooler temperatures and more precipitation. In addition, we predicted multiple areas of secondary contact zones where the two species co-occur, potentially facilitating gene exchange and hybridization. This study provides the most comprehensive understanding of the genomic epidemiology of histoplasmosis in the USA and lays a blueprint for the study of invasive fungal diseases.

Diagnosis of Coccidioidomycosis with the Second-Generation Miravista IgG and IgM Enzyme Immunoassay and the Role of Adding Miravista Coccidioides Antigen Detection to Immunodiagnostic Assays

In the present study, we validate and compare the second-generation Miravista Coccidioides IgG and IgM enzyme immunoassays (EIA) (MiraVista Diagnostics [MVD] Ab EIA) to Meridian Diagnostics Coccidioides IgG and IgM EIA (Meridian Ab EIA), immunodiffusion (ID) and complement fixation (CF). We also evaluated whether the addition of Coccidioides antigen testing to anti-Coccidioides antibody testing increased the sensitivity for the diagnosis of currently active coccidioidomycosis. We retrospectively studied 555 patients evaluated at Valleywise Health Medical Center between January 2013 and May 2017 for whom coccidioidomycosis was suspected and samples were submitted to MVD for testing. Specimens were tested for antigen in the MVD antigen enzyme immunoassay (MVD Ag EIA) and for IgG and IgM antibodies with MVD and Meridian Diagnostics EIAs. ID and CF were obtained from medical records. Sensitivity and specificity were 83.0% and 91.1% or MVD Ab EIA, 69.3% and 99.7% for Meridian Ab EIA, 85.4% and 100% for ID and 65.5% and 100% for CF. Combined MVD antigen and antibody detection by EIA and ID resulted in increased sensitivity in disseminated and pulmonary disease (MVD Ag/MVD Ab: 100%, 88.3%; MVD Ag/Meridian Ab: 98.2%, 78.6%; and MVD Ag/ID: 100%, 91.7%). The detection of antibodies by MVD EIA was more sensitive than Meridian EIA or CF but similar to ID. This study supports the use of antigen testing in immunocompromised patients and those with suspected disseminated disease. Furthermore, the addition of antigen detection by EIA to antibody detection resulted in higher sensitivity of all serological tests.

The WHO fungal priority pathogens list: a crucial reappraisal to review the prioritisation

In October, 2022, WHO published the first fungal priority pathogen list, which categorised 19 fungal entities into three priority groups (critical, high, and medium), for prioritisation of research efforts. The final ranking was determined via multiple criteria decision analysis, considering both research and development needs and perceived public health importance. In this Personal View, we discuss the positioning of the fungal pathogens, namely, Mucorales, Candida spp, Histoplasma spp, Coccidioides and Paracoccidioides spp, Fusarium spp, eumycetoma causative agents, Talaromyces marneffei, and Pneumocystis jirovecii, while expressing concerns about potential disparities between the WHO fungal priority pathogen list ranking and the actual disease burden associated with these pathogens. Finally, we propose a revised prioritisation list that also considers the regional disparities in the burden of fungal diseases.

Histoplasmosis in Taiwan: Case Summary and Literature Review

Histoplasmosis is a global infection caused by the thermally dimorphic fungus, Histoplasma capsulatum complex. It is endemic in the United States, as well as in Central and South America. In Taiwan, histoplasmosis is rare, with the first reported case not occurring until 1977. We summarized a total of 17 cases reported in Taiwan over the past 40 years and provided detailed descriptions for four probable indigenous cases. Due to the lack of rapid diagnostic tools and clinical suspicion, histoplasmosis may be underdiagnosed in Taiwan. We recognize that a limitation of our review is the lack of data on the environmental surveillance for H. capsulatum complex in Taiwan. Conducting a further phylogenetic analysis on both environmental and clinical isolates would provide valuable evidence for the region.

Impact of climate change and natural disasters on fungal infections

The effects of climate change and natural disasters on fungal pathogens and the risks for fungal diseases remain incompletely understood. In this literature review, we examined how fungi are adapting to an increase in the Earth's temperature and are becoming more thermotolerant, which is enhancing fungal fitness and virulence. Climate change is creating conditions conducive to the emergence of new fungal pathogens and is priming fungi to adapt to previously inhospitable environments, such as polluted habitats and urban areas, leading to the geographical spread of some fungi to traditionally non-endemic areas. Climate change is also contributing to increases in the frequency and severity of natural disasters, which can trigger outbreaks of fungal diseases and increase the spread of fungal pathogens. The populations mostly affected are the socially vulnerable. More awareness, research, funding, and policies on the part of key stakeholders are needed to mitigate the effects of climate change and disaster-related fungal diseases.

Endemic Fungal Infective Endocarditis Caused by Coccidioides, Blastomyces and Histoplasma Species in the United States

We describe a recent case of Coccidioides bioprosthetic aortic valve infective endocarditis successfully managed at our institution. This led us to perform a literature review of endemic fungal infective endocarditis in the United States caused by Coccidioides, Blastomyces, and Histoplasma. Symptoms preceded infective endocarditis diagnosis by several months. Patients with Coccidioides and Blastomyces infective endocarditis were younger with fewer comorbid conditions. Valvular involvement was relatively uncommon in Blastomyces infective endocarditis (27%). Fungemia was noted in patients with infective endocarditis due to Histoplasma (30%) and Coccidioides (18%). Mortality rates for infective endocarditis were high (Histoplasma, 46%; Coccidioides, 58%; Blastomyces, 80%); infective endocarditis was commonly diagnosed post-mortem (Coccidioides, 58%; Blastomyces, 89%). Most surviving patients with infective endocarditis (Histoplasma, 79%; Coccidioides, 80%) underwent valve surgery along with prolonged antifungal therapy. The two surviving patients with Blastomyces infective endocarditis received antifungal therapy without surgery.

[Innovative therapies for treatment of invasive fungal diseases]

Invasive fungal diseases (IFD) are difficult to treat and pose a significant threat to immunocompromised individuals. Current antifungal agents face limitations, including antifungal resistance and adverse effects. This review aims to give a comprehensive overview of emerging treatment strategies.Novel drugs in development are Ibrexafungerp, an orally available triterpenoid inhibiting glucan synthesis, and Rezafungin representing the echinocandins with extended half-life and improved tissue penetration, both recently licensed for certain indications. Fosmanogepix targets glycosylphosphatidylinositol biosynthesis, while Olorofim, an orotomide, inhibits fungal nucleic acid synthesis, both currently assessed in advanced clinical trials.Immunotherapeutic approaches include immune checkpoint inhibitors to enhance immune response in immunosuppressed individuals and fungal-specific allogeneic CAR-T cell therapy. For prophylactic purpose in high-risk populations to develop IFD, monoclonal antibodies against different virulence factors of Candida spp. have been discovered but are not yet seen in clinical trials. Vaccines against distinct fungal antigens as well as pan fungal vaccines to prevent IFD are under development in preclinical stages, notably for Candida spp., Cryptococcus spp., and Aspergillus spp., however, their clinical value is still discussed.In summary, major advances to treat IFD have been observed, but challenges for their establishment in the clinical routine persist.

Advanced genetic techniques in fungal pathogen research

Although fungi have been important model organisms for solving genetic, molecular, and ecological problems, recently, they are also becoming an important source of infectious disease. Despite their high medical burden, fungal pathogens are understudied, and relative to other pathogenic microbes, less is known about how their gene functions contribute to disease. This is due, in part, to a lack of powerful genetic tools to study these organisms. In turn, this has resulted in inappropriate treatments and diagnostics and poor disease management. There are a variety of reasons genetic studies were challenging in pathogenic fungi, but in recent years, most of them have been overcome or advances have been made to circumvent these barriers. In this minireview, we highlight how recent advances in genetic studies in fungal pathogens have resulted in the discovery of important biology and potential new antifungals and have created the tools to comprehensively study these important pathogens.

Disseminated Histoplasmosis in a Patient with Myelofibrosis on Ruxolitinib: A Case Report and Review of the Literature on Ruxolitinib-Associated Invasive Fungal Infections

Ruxolitinib, a selective inhibitor of Janus kinases, is a standard treatment for intermediate/high-risk myelofibrosis (MF) but is associated with a predisposition to opportunistic infections, especially herpes zoster. However, the incidence and characteristics of invasive fungal infections (IFIs) in these patients remain uncertain. In this report, we present the case of a 59-year-old woman with MF who developed disseminated histoplasmosis after seven months of ruxolitinib use. The patient clinically improved after ten weeks of combined amphotericin B and azole therapy, and ruxolitinib was discontinued. Later, the patient received fedratinib, a relatively JAK2-selective inhibitor, without relapse of histoplasmosis. We also reviewed the literature on published cases of proven IFIs in patients with MF who received ruxolitinib. Including ours, we identified 28 such cases, most commonly due to Cryptococcus species (46%). IFIs were most commonly disseminated (39%), followed by localized lung (21%) infections. Although uncommon, a high index of suspicion for opportunistic IFIs is needed in patients receiving JAK inhibitors. Furthermore, the paucity of data regarding the optimal management of IFIs in patients treated with JAK inhibitors underscore the need for well-designed studies to evaluate the epidemiology, pathobiology, early diagnosis, and multimodal therapy of IFIs in patients with hematological malignancies receiving targeted therapies.

MSG-15: Super-Bioavailability Itraconazole Versus Conventional Itraconazole in the Treatment of Endemic Mycoses-A Multicenter, Open-Label, Randomized Comparative Trial

Background

Invasive fungal disease caused by dimorphic fungi is associated with significant morbidity and mortality. Super-bioavailability itraconazole (SUBA-itra) is a novel antifungal agent with pharmacokinetic advantages over currently available formulations. In this prospective comparative study, we report the outcomes of patients with endemic fungal infections (histoplasmosis, blastomycosis, coccidioidomycosis, and sporotrichosis).

Methods

This open-label randomized trial evaluated the efficacy, safety, and pharmacokinetics SUBA-itra compared with conventional itraconazole (c-itra) treatment for endemic fungal infections. An independent data review committee determined responses on treatment days 42 and 180.

Results

Eighty-eight patients were enrolled for IFD (SUBA-itra, n = 42; c-itra, n = 46) caused by Histoplasma (n = 51), Blastomyces (n = 18), Coccidioides (n = 13), or Sporothrix (n = 6). On day 42, clinical success was observed with SUBA-itra and c-itra on day 42 (in 69% and 67%, respectively, and on day 180 (in 60% and 65%). Patients treated with SUBA-itra exhibited less drug-level variability at days 7 (P = .03) and 14 (P = .06) of randomized treatment. The concentrations of itraconazole and hydroxyitraconazole were comparable between the 2 medications (P = .77 and P = .80, respectively). There was a trend for fewer adverse events (AEs; 74% vs 87%, respectively; P = .18) and serious AEs (10% vs 26%; P = .06) in the SUBA-itra-treated patients than in those receiving c-itra. Serious treatment-emergent AEs were less common in SUBA-itra-treated patients (12% vs 50%, respectively; P < .001).

Conclusions

SUBA-itra was bioequivalent, well tolerated, and efficacious in treating endemic fungi, with a more favorable safety profile than c-itra.

Clinical Trials Registration

NCT03572049.

An Incarcerated Individual With Weight Loss and Interstitial Pulmonary Infiltrates

A man with HIV had syncopal episodes and hypoxemia after recent exposure to SARS-CoV-2; computed tomography revealed diffuse bilateral pulmonary micronodular opacities, a 2.2-cm nodule in the lingula, and mediastinal and hilar lymphadenopathy. What is the diagnosis and what would you do next?

Histoplasmosis in Solid Organ Transplantation

Histoplasma capsulatum, the etiological agent for histoplasmosis, is a dimorphic fungus that grows as a mold in the environment and as a yeast in human tissues. It has a broad global distribution with shifting epidemiology during recent decades. While in immunocompetent individuals infection is usually self-resolving, solid organ transplant recipients are at increased risk of symptomatic disease with dissemination to extrapulmonary tissue. Diagnosis of histoplasmosis relies on direct observation of the pathogen (histopathology, cytopathology, and culture) or detection of antigens, antibodies, or nucleic acids. All transplant recipients with histoplasmosis warrant therapy, though the agent of choice and duration of therapy depends on the severity of disease. In the present article, we describe the pathogenesis, epidemiology, clinical manifestations and management of histoplasmosis in solid organ transplant recipients.

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.

Detection of Histoplasma capsulatum and Blastomyces dermatitidis antigens in serum using a single quantitative enzyme immunoassay

Histoplasma and Blastomyces antigen detection assays are commonly used diagnostic tools. However, a high level of cross-reactivity between these antigens prevents definitive pathogen identification by these assays alone. Retrospective analysis of 3,529 patients with Histoplasma and Blastomyces antigen testing performed on the same serum sample yielded an overall percent agreement of 99.3% (3,506 of 3,529; kappa: 0.859) between the two assays, suggesting that use of a single assay to detect both antigens may be an alternative diagnostic approach. We assessed performance of the Gotham BioTech Blastomyces antigen (GBA) enzyme immunoassay (EIA) (Portland, Maine) for detection of Blastomyces and Histoplasma antigens in serum. Comparison to the MiraVista Diagnostics Blastomyces (MVB) EIA showed 100% positive (24 of 24), negative (57 of 57), and overall (81 of 81) percent agreement. Additionally, 171 sera were used to compare the GBA EIA to the MiraVista Diagnostics Histoplasma (MVH) EIA, which showed 91.3% (63 of 69), 98% (100 of 102), and 95.3% (163 of 171) positive, negative, and overall percent agreement, respectively. Among eight patients with discordant GBA/MVH EIA results, seven had additional fungal testing performed, and results suggested that the MVH and GBA results were inaccurate for two and five samples, respectively. Overall, this study suggests that the GBA EIA has a high level of agreement with both of the commonly used, individual Blastomyces and Histoplasma antigen EIAs. By taking advantage of the high level of cross-reactivity between Blastomyces and Histoplasma antigen EIAs, utilization of a single antigen detection assay for these fungi provides an opportunity to optimize test utilization and decrease patient cost while maintaining a high level of diagnostic accuracy.

Invasive Fungal Infections and Oomycoses in Cats: 1. Diagnostic approach

CLINICAL RELEVANCE

In contrast to superficial fungal infections, such as dermatophytosis, invasive fungal infections (IFIs) are characterised by penetration of tissues by fungal elements. Disease can spread locally within a region or can disseminate haematogenously or via the lymphatics. The environment is the most common reservoir of infection. Since fungal spores are airborne, indoor cats are also susceptible to IFIs. Some environmental fungi are ubiquitous and present globally, while others are endemic or hyperendemic within specific geographic regions. Zoonotic pathogens include Microsporum canis, Sporothrix schenckii and Sporothrix brasiliensis.

AIM

In the first of a two-part article series, the approach to the investigation of feline IFIs and oomycoses is reviewed. As well as tips for diagnosis, and information on the ecological niche and distribution of fungal pathogens, the review covers clinical presentation of the most common IFIs, including cryptococcosis, histoplasmosis, blastomycosis, coccidioidomycosis, sporotrichosis, phaeohyphomycosis, aspergillosis and dermatophytic pseudomycetoma, as well as the oomycoses pythiosis, lagenidiosis and paralagenidiosis. In Part 2, the spectrum of activity, mechanisms of action, pharmacokinetic and pharmacodynamic properties and adverse effects of antifungal drugs are reviewed, and the treatment and prognosis for specific IFIs and oomycoses are discussed.

EVIDENCE BASE

The review draws on published evidence and the authors' combined expertise in feline medicine, mycology, dermatology, clinical pathology and anatomical pathology.

Progressive disseminated histoplasmosis: The experience in one non-endemic medical center

Histoplasmosis, the most common endemic mycosis in North America, presents in a myriad of ways, spanning the spectrum from self-limiting pneumonia to progressive disseminated histoplasmosis (PDH). Toward better describing contemporary histoplasmosis syndromes, risks, and outcomes, this single-center retrospective cohort study was performed (2009-2019). The population who developed PDH was similar to that with other forms of histoplasmosis (OFH) except for higher rates of preexisting immunocompromising conditions (91.3% vs. 40%, P < .001) and a trend toward receiving more chronic immunosuppression (65.2% vs. 33.3%, P = .054) compared to those with OFH. Diagnosis was most frequently achieved by urinary or serum antigen positivity. People with PDH more frequently tested positive compared to those with OFH, but negative tests did not rule out histoplasmosis. Median time to diagnosis was prolonged among people with both PDH and OFH (32 vs. 31 days, respectively). Following diagnosis, people with PDH received more liposomal amphotericin (78.3% vs. 20%, P < .001). Subsequent survival at 90 and 365 days and treatment response were similar in both groups. Patients with PDH were more often hospitalized (95.7% vs. 60%, P = .006); however, once admitted, there were no differences in hospital length of stay or intensive care unit admission rate. The challenges of diagnosing histoplasmosis based on clinical presentation alone highlight the need for heightened awareness of these entities especially given the recent reports on expanded endemicity and delays in diagnosis.

A Clinicopathological Categorization System for Clinical Research in Coccidioidomycosis

A wide array of clinical manifestations follow infection with Coccidioides immitis or Coccidioides posadasii, ranging from asymptomatic infection to life-threatening pulmonary disease or extrapulmonary dissemination and meningitis. Epidemiological studies require consistent definitions of cases and their comparative clinical features. Understanding host and pathogen determinants of the severity of coccidioidomycosis also requires that specific clinical features (such as coccidioidal meningitis) and their overlap be precisely defined and quantified. Here we propose a system for categorization of outcomes of coccidioidomycosis in individuals who are not overtly immunocompromised that harmonizes clinical assessments during translational research of this increasingly common disease.

Blastomycosis Endocarditis: Case Report and Literature Review

We report successful treatment of a case of disseminated blastomycosis originating in the right lung, with involvement of the right pleural space, multiple ribs and vertebral bodies, and the pericardium and mitral valve endocarditis. The 22-year-old patient presented with a 13-month history of right lower lobe pneumonia associated with fevers, night sweats, rib pain, and 27-kg weight loss. Pathology examination revealed Blastomyces from multiple biopsies of inflammatory masses in the right thorax. After a 4-week induction with liposomal amphotericin followed by oral itraconazole, the patient had complete resolution of the clinical and laboratory findings of blastomycosis.

A Phylogeographic Description of Histoplasma capsulatum in the United States

Histoplasmosis is one of the most under-diagnosed and under-reported endemic mycoses in the United States. Histoplasma capsulatum is the causative agent of this disease. To date, molecular epidemiologic studies detailing the phylogeographic structure of H. capsulatum in the United States have been limited. We conducted genomic sequencing using isolates from histoplasmosis cases reported in the United States. We identified North American Clade 2 (NAm2) as the most prevalent clade in the country. Despite high intra-clade diversity, isolates from Minnesota and Michigan cases were predominately clustered by state. Future work incorporating environmental sampling and veterinary surveillance may further elucidate the molecular epidemiology of H. capsulatum in the United States and how genomic sequencing can be applied to the surveillance and outbreak investigation of histoplasmosis.

Trends of Azole Antifungal Prescription in the United States: Medicare Part D Provider Utilization and Payment Data Analysis

Background

Invasive fungal infections carry a substantial risk of mortality and morbidity. Azole antifungals are used in the treatment of such infections; however, their extensive use can lead to the emergence of antifungal resistance and increased costs to patients and healthcare systems. The aim of this study is to evaluate trends in these antifungals use and costs.

Methods

The secular and regional trends of outpatient azole antifungals were analyzed using Medicare Part D Prescriber Public Use Files for the years 2013-2020. The total days supply (TDS), total drug cost (TDC) per 100 000 enrollees, and cost per day (CPD) were evaluated.

Results

The azole antifungal TDS for Medicare Part D enrollees increased by 12% between 2013 and 2020, and increases were noted for each azole. Southern US regions had the highest TDS, with Arizona having the highest TDS among US states in 2020. Cost analysis showed that TDC of all azoles has increased by 93% over the years, going up from $123 316 in 2013 to $238 336 per 100 000 enrollees in 2020. However, CPD showed an increase only for fluconazole and isavuconazole, with CPD of $1.62 per day and $188.30 per day, respectively.

Conclusions

Combined azole antifungal prescriptions TDS increased among Medicare Part D enrollees. The trend in CPD was mixed, whereas overall costs consistently increased over the same period. Such findings provide an insight into the impact of azole antifungal prescriptions, and increasing use could foreshadow more antifungal resistance. Continued studies to evaluate different prescribers' trends are warranted.

Epidemiology of Coccidioidomycosis in the Veterans Health Administration, 2013-2022

We describe the epidemiology of coccidioidomycosis among a national cohort of Veterans. Using electronic health record data from adults tested for coccidioidomycosis between 1 January 2013 and 31 December 2022, we analyzed differences in baseline demographics (age, sex, race/ethnicity, birth country, comorbidities, residence, and Charlson Comorbidity Index score) between 4204 coccidioidomycosis-test-positive and 63,322 test-negative Veterans. Log-binomial regression models with adjusted risk ratios (aRRs) were used to evaluate risk factors associated with coccidioidomycosis including dissemination, hospitalization, and mortality. Case counts and incidence rates were highest in select counties in Arizona and California where Coccidioides is endemic. Coccidioidomycosis-positive Veterans were younger, more likely to be male, and Philippine-born. The risk factors most highly associated with being coccidioidomycosis-positive included Native Hawaiian/Pacific Islander (aRR 1.068 [95%CI: 1.039-1.098]), Asian (aRR 1.060 [95%CI: 1.037-1.083]), Black (aRR 1.029 [95%CI: 1.022-1.036]), American Indian/Alaska Native (aRR 1.026 [95%CI: 1.004-1.048]) race, and Hispanic/Latino ethnicity (aRR 1.021 [95%CI: 1.013-1.028]). Black race (aRR: 1.058 [95%CI: 1.037-1.081]) and Hispanic/Latino ethnicity (aRR 1.018 [95%CI: 1.0003-1.036]) were also associated with disseminated coccidioidomycosis, strengthening the evidence for the association of coccidioidomycosis, including severe infections, with specific racial and ethnic groups. There were no statistically significant differences in hospitalization within 45 days of testing or 30-day all-cause mortality. Improving our understanding of coccidioidomycosis risk factors is important for targeted prevention strategies and to reduce delays in diagnosis and ineffective treatment.

Fatal septic shock due to disseminated coccidioidomycosis: a case series and review of the literature

BACKGROUND

Coccidioidomycosis is a fungal infection endemic to the southwestern United States and regions of Latin America. Disseminated disease occurs in < 1% of cases. Septic shock is even rarer, with high mortality despite therapy. We describe two cases of coccidioidal septic shock. Both patients were older men of Filipino ancestry presenting with respiratory failure and vasopressor-dependent shock. Antifungal drugs were initiated after failure to improve with empiric antibiotics; in both, Coccidioides was isolated from respiratory cultures. Despite aggressive care, both patients ultimately died of their infections. We provide a review of the published literature on this topic.

CONCLUSIONS

Most of the 33 reported cases of coccidioidal septic shock occurred in men (88%) of non-white race and ethnicity (78%). The overall mortality rate was 76%. All survivors received amphotericin B as part of their treatment. Coccidioidomycosis-related septic shock is a rare disease with poor outcomes; delays in diagnosis and treatment are common. Improved diagnostic testing for coccidioidomycosis could enhance recognition of this disease in the future. Although data are limited, early treatment with amphotericin B in cases of coccidioidal septic shock may reduce mortality.

Minimizing the Risk of Donor-Derived Events and Maximizing Organ Utilization Through Education and Policy Development

Herein, we review the current knowledge of donor-derived disease and current US Organ Procurement and Transplantation Network policies to minimize the risk. During the process, we also consider actions to further mitigate the risk of donor-derived disease. The overarching goal is to provide an infectious disease perspective on the complex decision of organ acceptance for transplant programs and candidates.

Review of Clinical and Laboratory Diagnostics for Coccidioidomycosis

Coccidioidomycosis is a fungal disease associated with soil exposure that frequently goes undiagnosed due at least in part to its nonspecific presentation and the lack of clinical suspicion by health care providers. Currently available diagnostics for coccidioidomycosis offer qualitative results that can suffer from low specificity, while semiquantitative assays are labor-intensive and complex and can require multiple days to complete. Furthermore, significant confusion exists regarding the optimal diagnostic algorithms and appropriate usage of available diagnostic tests. This review aims to inform clinical laboratorians and treating clinicians about the current diagnostic landscape, appropriate diagnostic strategies, and future diagnostic directions for coccidioidomycosis, which is expected to become more prevalent due to increased migration into areas of endemicity and climate changes.

Headaches in a Horseback Rider

An immunocompetent woman presented with headaches. She previouslyworked at a farm in upstate New York. Brain MRI noted pituitary enlargement and neurosurgerypursued trans-sphenoidal pituitary biopsy. Histopathology revealed ill-defined granulomaswith clusters of yeast, consistent with Histoplasma.

Was Coccidioides a Pre-Columbian Hitchhiker to Southcentral Washington?

Coccidioides immitis, a pathogenic environmental fungus that causes Valley fever (coccidioidomycosis) primarily in the American Southwest and parts of Central and South America, has emerged over the past 12 years in the Columbia River Basin region, near the confluence with the Yakima River, in southcentral Washington state, USA. An initial autochthonous Washington human case was found in 2010, stemming from a wound derived from soil contamination during an all-terrain vehicle crash. Subsequent analysis identified multiple positive soil samples from the park where the crash occurred (near the Columbia River in Kennewick, WA), and from another riverside location several kilometers upstream from the park location. Intensified disease surveillance identified several more cases of coccidioidomycosis in the region that lacked any relevant travel history to known endemic locales. Genomic analysis of both patient and soil isolates from the Washington cases determined that all samples from the region are phylogenetically closely related. Given the genomic and the epidemiological link between case and environment, C. immitis was declared to be a newly endemic fungus in the region, spawning many questions as to the scope of its presence, the causes of its recent emergence, and what it predicts about the changing landscape of this disease. Here, we review this discovery through a paleo-epidemiological lens in the context of what is known about C. immitis biology and pathogenesis and propose a novel hypothesis for the cause of the emergence in southcentral Washington. We also try to place it in the context of our evolving understanding of this regionally specific pathogenic fungus.

Pulmonary Histoplasmosis: A Clinical Update

Histoplasma capsulatum, the etiological agent for histoplasmosis, is a dimorphic fungus that grows as a mold in the environment and as a yeast in human tissues. The areas of highest endemicity lie within the Mississippi and Ohio River Valleys of North America and parts of Central and South America. The most common clinical presentations include pulmonary histoplasmosis, which can resemble community-acquired pneumonia, tuberculosis, sarcoidosis, or malignancy; however, certain patients can develop mediastinal involvement or progression to disseminated disease. Understanding the epidemiology, pathology, clinical presentation, and diagnostic testing performance is pivotal for a successful diagnosis. While most immunocompetent patients with mild acute or subacute pulmonary histoplasmosis should receive therapy, all immunocompromised patients and those with chronic pulmonary disease or progressive disseminated disease should also receive therapy. Liposomal amphotericin B is the agent of choice for severe or disseminated disease, and itraconazole is recommended in milder cases or as "step-down" therapy after initial improvement with amphotericin B. In this review, we discuss the current epidemiology, pathology, diagnosis, clinical presentations, and management of pulmonary histoplasmosis.