Evaluation of the Analytical Performance of a Lateral Flow Assay for the Detection of Anti-Coccidioides Antibodies in Human Sera-Argentina

Coccidiomycosis is a potentially life-threatening fungal infection endemic to certain regions of Argentina. The infection is caused by Coccidioides spp. and is primarily diagnosed by Coccidioides antibody (Ab) detection. Access to rapid, highly accurate diagnostic testing is critical to ensure prompt antifungal therapy. The sōna Coccidioides Ab Lateral Flow Assay (LFA) performs faster and requires less laboratory infrastructure and equipment compared with other Ab detection assays, potentially providing a substantial improvement for rapid case screening in coccidioidomycosis-endemic regions; however, validation of this test is needed. Thus, we aimed to evaluate the analytical performance of the sōna Coccidioides Ab (LFA) and compare agreement with anti-Coccidioides Ab detection assays. A total of 103 human sera specimens were tested, including 25 specimens from patients with coccidioidomycosis and 78 from patients without coccidioidomycosis. The sōna Coccidioides Ab Lateral Flow Assay (LFA) was performed with a sensitivity of 88%, and specificity and accuracy of 87%. Furthermore, the Coccidioides Ab LFA had good agreement with other anti-Coccidioides Ab detection assays. Our findings suggest the sōna Coccidioides Ab LFA has satisfactory performance and may be useful for diagnosing coccidioidomycosis in endemic regions.

The Known and Unknown "Knowns" of Human Susceptibility to Coccidioidomycosis

Coccidioidomycosis occurs after inhalation of airborne spores of the endemic, dimorphic fungus, Coccidioides. While the majority of individuals resolve the infection without coming to medical attention, the fungus is a major cause of community-acquired pneumonia in the endemic region, and chronic pulmonary and extrapulmonary disease poses significant personal and economic burdens. This review explores the literature surrounding human susceptibility to coccidioidomycosis, including chronic pulmonary and extrapulmonary dissemination. Over the past century of study, themes have emerged surrounding factors impacting human susceptibility to severe disease or dissemination, including immune suppression, genetic susceptibility, sex, pregnancy, and genetic ancestry. Early studies were observational, frequently with small numbers of cases; several of these early studies are highly cited in review papers, becoming part of the coccidioidomycosis "canon". Specific genetic variants, sex, and immune suppression by TNF inhibitors have been validated in later cohort studies, confirming the original hypotheses. By contrast, some risk factors, such as ABO blood group, Filipino ancestry, or lack of erythema nodosum among black individuals, are repeated in the literature despite the lack of supporting studies or biologic plausibility. Using examination of historical reports coupled with recent cohort and epidemiology studies, evidence for commonly reported risk factors is discussed.

A microbial risk assessor's guide to Valley Fever (Coccidioides spp.): Case study and review of risk factors

Valley Fever is a respiratory disease caused by inhalation of arthroconidia, a type of spore produced by fungi within the genus Coccidioides spp. which are found in dry, hot ecosystems of the Western Hemisphere. A quantitative microbial risk assessment (QMRA) for the disease has not yet been performed due to a lack of dose-response models and a scarcity of quantitative occurrence data from environmental samples. A literature review was performed to gather data on experimental animal dosing studies, environmental occurrence, human disease outbreaks, and meteorological associations. As a result, a risk framework is presented with information for parameterizing QMRA models for Coccidioides spp., with eight new dose-response models proposed. A probabilistic QMRA was conducted for a Southwestern US agricultural case study, evaluating eight scenarios related to farming occupational exposures. Median daily workday risks for developing severe Valley Fever ranged from 2.53 × 10-7 (planting by hand while wearing an N95 facemask) to 1.33 × 10-3 (machine harvesting while not wearing a facemask). The literature review and QMRA synthesis confirmed that exposure to aerosolized arthroconidia has the potential to result in high attack rates but highlighted that the mechanistic relationships between environmental conditions and disease remain poorly understood. Recommendations for Valley Fever risk assessment research needs in order to reduce disease risks are discussed, including interventions for farmers.

Galleria mellonella Model of Coccidioidomycosis for Drug Susceptibility Tests and Virulence Factor Identification

Coccidioidomycosis (CM) can manifest as respiratory and disseminated diseases that are caused by dimorphic fungal pathogens, such as Coccidioides species. The inhaled arthroconidia generated during the saprobic growth phase convert into multinucleated spherules in the lungs to complete the parasitic lifecycle. Research on coccidioidal virulence and pathogenesis primarily employs murine models typically associated with low lethal doses (LD100 < 100 spores). However, the Galleria model has recently garnered attention due to its immune system bearing both structural and functional similarities to the innate system of mammals. Our findings indicate that Coccidioides posadasii can convert and complete the parasitic cycle within the hemocoel of the Galleria larva. In Galleria, the LD100 is between 0.5 and 1.0 × 106 viable spores for the clinical isolate Coccidioides posadasii C735. Furthermore, we demonstrated the suitability of this model for in vivo antifungal susceptibility tests to validate the bioreactivity of newly discovered antifungals against Coccidioides. Additionally, we utilized this larva model to screen a Coccidioides posadasii mutant library showing attenuated virulence. Similarly, the identified attenuated coccidioidal mutants displayed a loss of virulence in a commonly used murine model of coccidioidomycosis. In this study, we demonstrated that Galleria larvae can be applied as a model for studying Coccidioides infection.

Hypoxemic Respiratory Failure and Coccidioidomycosis-Associated Acute Respiratory Distress Syndrome

Background

Severe coccidioidomycosis presenting with respiratory failure is an uncommon manifestation of disease. Current knowledge of this condition is limited to case reports and small case series.

Methods

A retrospective multicenter review of patients with coccidioidomycosis-associated acute respiratory distress syndrome (CA-ARDS) was conducted. It assessed clinical and laboratory variables at the time of presentation, reviewed the treatment course, and compared this cohort with a national database of patients with noncoccidioidomycosis ARDS. Survivors and nonsurvivors of coccidioidomycosis were also compared to determine prognostic factors.

Results

In this study, CA-ARDS (n = 54) was most common in males, those of Hispanic ethnicity, and those with concurrent diabetes mellitus. As compared with the PETAL network database (Prevention and Early Treatment of Acute Lung Injury; n = 1006), patients with coccidioidomycosis were younger, had fewer comorbid conditions, and were less acidemic. The 90-day mortality was 15.4% for patients with coccidioidomycosis, as opposed to 42.6% (P < .0001) for patients with noncoccidioidomycosis ARDS. Patients with coccidioidomycosis who died, as compared with those who survived, were older, had higher APACHE II scores (Acute Physiology and Chronic Health Evaluation), and did not receive corticosteroid therapy.

Conclusions

CA-ARDS is an uncommon but morbid manifestation of infection. When compared with a national database, the overall mortality appears favorable vs other causes of ARDS. Patients with CA-ARDS had a low overall mortality but required prolonged antifungal therapy. The utility of corticosteroids in this condition remains unconfirmed.

Antigenic Relatedness between Mannans from Coccidioides immitis and Coccidioides posadasii Spherules and Mycelia

Immunoassays for cell wall mannans that are excreted into serum and urine have been used as an aid in the diagnosis of many disseminated fungal infections, including coccidioidomycosis. Antigen-detection immunoassays are critically dependent on the detection of an analyte, such as mannan, by antibodies that are specific to the analyte. The goal of this study was to evaluate the extent of cross-reactivity of polyclonal antibodies raised against Coccidioides spp. Analysis of antigenic relatedness between mannans from C. posadasii and C. immitis spherules and mycelia showed complete relatedness when evaluated by the method of Archetti and Horsfall, which was originally used to study the antigenic relationships between Influenzae virus isolates. In a further effort to validate the suitability of the antigenic relatedness calculation methodology for polysaccharide antigens, we also applied the method of Archetti and Horsfall to published results that had previously identified the major capsular serotypes of Cryptococcus species. The results of this analysis showed that Archetti and Horsfall's antigenic relatedness calculation correctly identified the major cryptococcal serotypes. Together, these results suggest that the method is applicable to polysaccharide antigens, and that immunoassays that detect Coccidioides mannans are likely to have good reactivity across Coccidioides species (inclusivity) due to the species' high level of antigenic relatedness.

Examining Miliary Disease Etiology in a Coccidioides-Endemic Center: A Retrospective Cohort Study

Background: A miliary pattern on chest imaging is often attributed to tuberculosis (TB) infection. However, a myriad of conditions can cause a miliary pattern, many of which are imminently life-threatening. Research Question: The primary aim of our study is to elucidate the potential causes of miliary chest imaging patterns to improve workup and empiric therapy selection. The secondary aims are to discern the predictors of miliary disease etiology and to determine whether appropriate empiric antimicrobial therapies were given. Study Design and Methods: In this retrospective cohort study, we searched a radiology database for patients with chest imaging studies described by the word "miliary". Subjects were excluded if they were under 18 years of age and if there were insufficient objective data to support a miliary disease etiology. A radiologist independently reviewed all imaging studies, and studies that did not appear to have a true miliary pattern were excluded. The collected data include patient demographics, immunocompromising risk factors, conditions associated with miliary disease, β-D-glucan levels, serum eosinophil count, and empiric therapies received. Results: From our 41-patient cohort, 22 patients (53.7%) were clinically diagnosed with coccidioidomycosis, 8 (19.5%) with TB, 7 (17.1%) with metastatic solid cancer, 1 (2.4%) with lymphoma, 1 (2.4%) with other (Mycobacterium simiae), and 3 (7.3%) with unknown diseases (the sum equals 42 patients because one individual was diagnosed with both coccidioidomycosis and TB). All six patients with greater than 500 eosinophils/μL were diagnosed with coccidioidomycosis. Of the 22 patients diagnosed with coccidioidomycosis, 20 (90.91%) were empirically treated with an antifungal regimen. Of the eight patients with TB, six were empirically treated for TB. Interpretation: Based on our data from a Coccidioides-endemic region with close proximity to tuberculosis-endemic areas, the leading cause of miliary disease is coccidioidomycosis, although TB and cancer are also common etiologies. Serum eosinophilia and elevated β-D-glucan levels were strongly predictive of coccidioidomycosis in our patient cohort with a miliary chest imaging pattern.

Advances in diagnosis and management of atypical spinal infections: A comprehensive review

Atypical spinal infections (ASIs) of the spine are a challenging pathology to management with potentially devastating morbidity and mortality. To identify patients with atypical spinal infections, it is important to recognize the often insidious clinical and radiographic presentations, in the setting of indolent and smoldering organism growth. Trending of inflammatory markers, and culturing of organisms, is essential. Once identified, the spinal infection should be treated with antibiotics and possibly various surgical interventions including decompression and possible fusion depending on spine structural integrity and stability. Early diagnosis of ASIs and immediate treatment of debilitating conditions, such as epidural abscess, correlate with fewer neurological deficits and a shorter duration of medical treatment. There have been great advances in surgical interventions and spinal fusion techniques for patients with spinal infection. Overall, ASIs remain a perplexing pathology that could be successfully treated with early diagnosis and immediate, appropriate medical, and surgical management.

Temporal tracheobronchial lymphadenopathy resolution is affected by initial severity and poorly correlated to serologic antibody testing in dogs with pulmonary coccidioidomycosis

OBJECTIVE

To determine associations between antibody serologic tests and tracheobronchial lymphadenopathy (TBL) in dogs with pulmonary coccidioidomycosis and identify variables associated with time to resolution of TBL.

ANIMALS

32 client owned dogs with newly diagnosed pulmonary coccidioidomycosis from October 2020 to February 2021.

METHODS

Prospective cohort study. Thoracic radiographs and anti-Coccidioides spp antibody serology were performed at baseline and once every 3 months until remission or for a maximum of 12 months. Radiographic tracheobronchial lymph node height, length, and area were measured and recorded as ratios via comparison with the length of the T4 vertebral body (LT4) and length of the manubrium. Severity of TBL was also subjectively categorized as mild, moderate, or severe.

RESULTS

Tracheobronchial lymphadenopathy was identified in 81% (26/32; 95% CI, 64% to 93%) of dogs. There was no relevant association between TBL presence or severity and antibody serology results. Tracheobronchial lymphadenopathy resolved in 72% (n = 18) of dogs at the 3-month evaluation. The median time to resolution of TBL after initiation of fluconazole was 96 days (range, 72 to 386 days). Univariate analysis identified increasing TBL severity (hazard ratio, 0.40; 95% CI, 0.19 to 0.84; P = .02) and length:LT4 ratio (hazard ratio, 0.41; 95% CI, 0.20 to 0.82; P = .01) as variables associated with reduced probability of resolution of TBL.

CLINICAL RELEVANCE

Antibody serologic test results are not clinically useful to predict TBL presence or severity in dogs with pulmonary coccidioidomycosis, and larger tracheobronchial lymph nodes are more likely to take longer to resolve. Resolution of TBL occurs in most dogs within 3 to 6 months after fluconazole administration.

Host tracheal and intestinal microbiomes inhibit Coccidioides growth in vitro

Coccidioidomycosis, also known as Valley fever, is a disease caused by the fungal pathogen Coccidioides. Unfortunately, patients are often misdiagnosed with bacterial pneumonia leading to inappropriate antibiotic treatment. Soil bacteria B. subtilis-like species exhibits antagonistic properties against Coccidioides in vitro; however, the antagonistic capabilities of host microbiota against Coccidioides are unexplored. We sought to examine the potential of the tracheal and intestinal microbiomes to inhibit the growth of Coccidioides in vitro. We hypothesized that an uninterrupted lawn of microbiota obtained from antibiotic-free mice would inhibit the growth of Coccidioides while partial in vitro depletion through antibiotic disk diffusion assays would allow a niche for fungal growth. We observed that the microbiota grown on 2xGYE (GYE) and CNA w/ 5% sheep's blood agar (5%SB-CNA) inhibited the growth of Coccidioides, but that grown on chocolate agar does not. Partial depletion of the microbiota through antibiotic disk diffusion revealed that microbiota depletion leads to diminished inhibition and comparable growth of Coccidioides growth to controls. To characterize the bacteria grown and narrow down potential candidates contributing to the inhibition of Coccidioides, 16s rRNA sequencing of tracheal and intestinal agar cultures and murine lung extracts was performed. The identity of host bacteria that may be responsible for this inhibition was revealed. The results of this study demonstrate the potential of the host microbiota to inhibit the growth of Coccidioides in vitro and suggest that an altered microbiome through antibiotic treatment could negatively impact effective fungal clearance and allow a niche for fungal growth in vivo.

Coccidioidomycosis Osteoarticular Dissemination

Valley fever or coccidioidomycosis is a pulmonary infection caused by species of Coccidioides fungi that are endemic to California and Arizona. Skeletal coccidioidomycosis accounts for about half of disseminated infections, with the vertebral spine being the preferred site of dissemination. Most cases of skeletal coccidioidomycosis progress to bone destruction or spread to adjacent structures such as joints, tendons, and other soft tissues, causing significant pain and restricting mobility. Manifestations of such cases are usually nonspecific, making diagnosis very challenging, especially in non-endemic areas. The lack of basic knowledge and research data on the mechanisms defining susceptibility to extrapulmonary infection, especially when it involves bones and joints, prompted us to survey available clinical and animal data to establish specific research questions that remain to be investigated. In this review, we explore published literature reviews, case reports, and case series on the dissemination of coccidioidomycosis to bones and/or joints. We highlight key differential features with other conditions and opportunities for mechanistic and basic research studies that can help develop novel diagnostic, prognostic, and treatment strategies.

Proceedings of the 2023 Division of Translational Toxicology Satellite Symposium

The 2023 annual Division of Translational Toxicology (DTT) Satellite Symposium, entitled "Pathology Potpourri," was held in Summerlin, Nevada, at the Society of Toxicologic Pathology's 41st annual meeting. The goal of this symposium was to present and discuss challenging diagnostic pathology and/or nomenclature issues. This article presents summaries of the speakers' talks along with select images that were used by the audience for voting and discussion. Various lesions and topics covered during the symposium included induced and spontaneous neoplastic and nonneoplastic lesions in the mouse liver, infectious and proliferative lesions in nonhuman primates, interesting presentations of mononuclear cell infiltrates in various animal models and a complex oral tumor in a rat.

Association between wildfires and coccidioidomycosis incidence in California, 2000-2018: a synthetic control analysis

The frequency and severity of wildfires in the Western United States have increased over recent decades, motivating hypotheses that wildfires contribute to the incidence of coccidioidomycosis, an emerging fungal disease in the Western United States with sharp increases in incidence observed since 2000. While coccidioidomycosis outbreaks have occurred among wildland firefighters clearing brush, it remains unknown whether fires are associated with an increased incidence among the general population.

Methods

We identified 19 wildfires occurring within California's highly endemic San Joaquin Valley between 2003 and 2015. Using geolocated surveillance records, we applied a synthetic control approach to estimate the effect of each wildfire on the incidence of coccidioidomycosis among residents that lived within a hexagonal buffer of 20 km radii surrounding the fire.

Results

We did not detect excess cases due to wildfires in the 12 months (pooled estimated percent change in cases: 2.8%; 95% confidence interval [CI] = -29.0, 85.2), 13-24 months (7.9%; 95% CI = -27.3, 113.9), or 25-36 months (17.4%; 95% CI = -25.1, 157.1) following a wildfire. When examined individually, we detected significant increases in incidence following three of the 19 wildfires, all of which had relatively large adjacent populations, high transmission before the fire, and a burn area exceeding 5,000 acres.

Discussion

We find limited evidence that wildfires drive increases in coccidioidomycosis incidence among the general population. Nevertheless, our results raise concerns that large fires in regions with ongoing local transmission of Coccidioides may be associated with increases in incidence, underscoring the need for field studies examining Coccidioides spp. in soils and air pre- and post-wildfires.

Fungal Osteomyelitis: A Systematic Review of Reported Cases

Fungal osteomyelitis is considered a rare disease, and the published literature mainly comprises case reports, case series and narrative reviews. A systematic review was undertaken to provide a practice-based global perspective on this disease, focusing on epidemiology and treatment strategies. We searched MEDLINE, EMBASE and Cochrane Library between the 3rd and 8th of March 2023 using a predefined search string. We included studies with at least one patient with a diagnosis of fungal osteomyelitis published before the 1st of January 2023. We included all study designs except for reviews, and we excluded non-English languages and grey literature. After exclusion, 678 studies, mostly case reports, were included. Descriptive analysis was performed on 1072 patients. The most common aetiological agent was Aspergillus (26.5%), followed by Candida (20.7%) and Mucor (16.8%), and the bones most frequently involved were the vertebrae. We described the characteristics of patients divided by site of infection, and we found that diabetes mellitus, disseminated fungal infection, surgery and local lesion were major risk factors. We also successfully associated duration of treatment with outcome. We provided a general overview of this rare disease, and we highlighted the need for high-quality investigations on the subject.

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.

Coccidioidomycosis Granulomas Informed by Other Diseases: Advancements, Gaps, and Challenges

Valley fever is a respiratory disease caused by a soil fungus, Coccidioides, that is inhaled upon soil disruption. One mechanism by which the host immune system attempts to control and eliminate Coccidioides is through granuloma formation. However, very little is known about granulomas during Coccidioides infection. Granulomas were first identified in tuberculosis (TB) lungs as early as 1679, and yet many gaps in our understanding of granuloma formation, maintenance, and regulation remain. Granulomas are best defined in TB, providing clues that may be leveraged to understand Coccidioides infections. Granulomas also form during several other infectious and spontaneous diseases including sarcoidosis, chronic granulomatous disease (CGD), and others. This review explores our current understanding of granulomas, as well as potential mechanisms, and applies this knowledge to unraveling coccidioidomycosis granulomas.

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.

Coccidioidomycosis and Host Microbiome Interactions: What We Know and What We Can Infer from Other Respiratory Infections

Between 70 and 80% of Valley fever patients receive one or more rounds of antibiotic treatment prior to accurate diagnosis with coccidioidomycosis. Antibiotic treatment and infection (bacterial, viral, fungal, parasitic) often have negative implications on host microbial dysbiosis, immunological responses, and disease outcome. These perturbations have focused on the impact of gut dysbiosis on pulmonary disease instead of the implications of direct lung dysbiosis. However, recent work highlights a need to establish the direct effects of the lung microbiota on infection outcome. Cystic fibrosis, chronic obstructive pulmonary disease, COVID-19, and M. tuberculosis studies suggest that surveying the lung microbiota composition can serve as a predictive factor of disease severity and could inform treatment options. In addition to traditional treatment options, probiotics can reverse perturbation-induced repercussions on disease outcomes. The purpose of this review is to speculate on the effects perturbations of the host microbiome can have on coccidioidomycosis progression. To do this, parallels are drawn to aa compilation of other host microbiome infection studies.

Fungal Pathogens as Causes of Acute Respiratory Illness in Hospitalized Veterans: Frequency of Fungal Positive Test Results Using Rapid Immunodiagnostic Assays

Fungal respiratory illnesses caused by endemic mycoses can be nonspecific and are often mistaken for viral or bacterial infections. We performed fungal testing on serum specimens from patients hospitalized with acute respiratory illness (ARI) to assess the possible role of endemic fungi as etiologic agents. Patients hospitalized with ARI at a Veterans Affairs hospital in Houston, Texas, during November 2016-August 2017 were enrolled. Epidemiologic and clinical data, nasopharyngeal and oropharyngeal samples for viral testing (PCR), and serum specimens were collected at admission. We retrospectively tested remnant sera from a subset of patients with negative initial viral testing using immunoassays for the detection of Coccidioides and Histoplasma antibodies (Ab) and Cryptococcus, Aspergillus, and Histoplasma antigens (Ag). Of 224 patient serum specimens tested, 49 (22%) had positive results for fungal pathogens, including 30 (13%) by Coccidioides immunodiagnostic assays, 19 (8%) by Histoplasma immunodiagnostic assays, 2 (1%) by Aspergillus Ag, and none by Cryptococcus Ag testing. A high proportion of veterans hospitalized with ARI had positive serological results for fungal pathogens, primarily endemic mycoses, which cause fungal pneumonia. The high proportion of Coccidioides positivity is unexpected as this fungus is not thought to be common in southeastern Texas or metropolitan Houston, though is known to be endemic in southwestern Texas. Although serological testing suffers from low specificity, these results suggest that these fungi may be more common causes of ARI in southeast Texas than commonly appreciated and more increased clinical evaluation may be warranted.

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.

Risk of Exposure to Coccidioides spp. in the Temblor Special Recreation Management Area (SRMA), Kern County, CA

The Temblor Mountain Special Recreation Area (SRMA) on the western flank of the San Joaquin Valley, CA, is located in the endemic area of Coccidioides, a fungal pathogen responsible for the increasing incidence of coccidioidomycosis (Valley fever). Recreationists in the SRMA, such as off-highway vehicle (OHV) drivers and mountain bikers who disturb the soils, are at risk of being exposed to airborne arthroconidia (asexual spores) of the pathogen. To reduce the risk of pathogen exposure for visitors, the Bureau of Land Management (BLM) plans to limit recreational activities to areas with a reduced pathogen presence. They envision an official OHV park in the future, by also restricting access to areas with ongoing restoration efforts and by limiting soil erosion in sensitive areas. To investigate which soils in the Temblor SRMA are most likely to support the growth of Coccidioides spp., soil samples were collected over a 3-year period from dominant soil types in a northern and a southern sampling area and analyzed for the pathogen using a culture-independent PCR-based method. In addition, soil pH and electrical conductivity were determined. The results of this study revealed slight genetic variance in the Coccidioides sequences obtained from the soils of the Temblor SRMA. An analysis of variance (ANOVA) could not confirm differences in soil pH and electrical conductivity (EC) between the different soil types investigated and between sites where the pathogen was detected compared to sites where it could not be found. However, the year of sampling appeared to have an influence on observed soil pH and EC, and the presence of the pathogen. Of all dominant soil types investigated, those belonging to the Littlesignal-Cochora association were the least likely to contain the pathogen, whereas soils of the Beam-Panoza-Hillbrick association appeared more supportive. In addition to pointing out OHV areas with lower pathogen exposure risk in the Temblor SRMA, recommendations were made to educate visitors and BLM workers about the risk of contracting Valley fever.

A Case of Extra-Articular Coccidioidomycosis in the Knee of a Healthy Patient

Coccidioidomycosis is a fungal infection endemic to the Southwestern United States. Extrapulmonary Coccidioides immitis infections are uncommon and occur more frequently in immunocompromised individuals. There is often a delay in diagnosis and treatment due to the chronic, indolent nature of these infections. The clinical presentation is often nonspecific, and includes joint pain, erythema, or localized swelling. Therefore, these infections may only be identified after initial treatment failure and further workup is pursued. The majority of reported cases of coccidioidomycosis involving the knee have had intra-articular involvement or extension. This report describes a rare case of peri-articular Coccidioides immitis abscess of the knee that does not communicate with the joint in a healthy patient. This case illustrates the low threshold needed for additional testing, such as fluid or tissue sampling of joint-related fluid collections if the etiology is unclear. A high index of suspicion is prudent to avoid diagnostic delay, particularly for individuals who either reside in or travel to endemic areas.

Valley fever, mimicker of malignancy

Coccidioidomycosis rates in endemic areas such as California and Arizona have been increasing in recent years. Most common manifestations in symptomatic individuals involve the lungs. Disseminated disease occurs when the infection spreads beyond the lungs. Disseminated disease occurs in about 1% of all coccidiomycosis cases. Diagnosis in classically non-endemic regions can be difficult as coccidiomycosis can mimic a variety of other illnesses which can lead to delays in initiating appropriate therapy. We report a case of severe disseminated coccidiomycosis involving the soft tissue, bone, and intra-abdominal organs in a previously healthy individual that was initially thought to be a malignancy. With climate change possibly altering the traditional endemic regions and expanding Coccidioides to new territories, this case reinforces the importance of maintaining a broad differential as well as awareness of disease manifestations for healthcare providers who do not regularly treat Coccidioides.

Advocating for Coccidioidomycosis to Be a Reportable Disease Nationwide in the United States and Encouraging Disease Surveillance across North and South America

Coccidioidomycosis (Valley fever) has been a known health threat in the United States (US) since the 1930s, though not all states are currently required to report disease cases. Texas, one of the non-reporting states, is an example of where both historical and contemporary scientific evidence define the region as endemic, but we don't know disease incidence in the state. Mandating coccidioidomycosis as a reportable disease across more US states would increase disease awareness, improve clinical outcomes, and help antifungal drug and vaccine development. It would also increase our understanding of where the disease is endemic and the relationships between environmental conditions and disease cases. This is true for other nations in North and South America that are also likely endemic for coccidioidomycosis, especially Mexico. This commentary advocates for US state and territory epidemiologists to define coccidioidomycosis as a reportable disease and encourages disease surveillance in other endemic regions across North and South America in order to protect human health and reduce disease burden.

Disseminated coccidioidomycosis in a patient on mycophenolate

Disseminated coccidioidomycosis is a rare but serious complication of fungal illness, with immunocompromised patients more susceptible to severe illness. Here we report a unique case of disseminated coccidioidomycosis in a patient on mycophenolate for treatment of polymyositis.

Modeling Chronic Coccidioidomycosis in Mice

Coccidioidomycosis, caused by the dimorphic pathogens Coccidioides posadasii and C. immitis, is a fungal disease endemic to the southwestern United States, Mexico, and some regions of Central and South America. The mouse is the primary model for studying pathology and immunology of disease. Mice in general are extremely susceptible to Coccidioides spp., which creates challenges in studying the adaptive immune responses that are required for host control of coccidioidomycosis. Here, we describe how to infect mice to model asymptomatic infection with controlled, chronic granulomas and a slowly progressive but ultimately fatal infection that has kinetics more similar to the human disease.

Fun with fungi: a comprehensive review of common fungal organisms encountered in cytology

The ability to detect and diagnose infection is essential in the practice of cytopathology. The identification of suppurative or granulomatous inflammation should prompt careful evaluation for infection. Many of the most commonly encountered fungal organisms demonstrate characteristic microscopic appearances that allow accurate identification even with routine cytology stains, particularly when considered in the context of clinical factors such as geographic location, social history, patient immune status, and symptoms. Given the vital role cytopathologists play in the accurate diagnosis or presumptive identification of infections, this review explores the epidemiology, clinical manifestations, and morphologic features of common fungal pathogens in addition to their differential diagnoses and ancillary testing methods.

Genome Organization and Copy-Number Variation Reveal Clues to Virulence Evolution in Coccidioides posadasii

The human fungal pathogen Coccidioides spp. causes valley fever, a treatment-refractory and sometimes deadly disease prevalent in arid regions of the western hemisphere. Fungal virulence in the mammalian host hinges on a switch between growth as hyphae and as large spherules containing infectious spores. How these virulence programs are encoded in the genome remains poorly understood. Drawing on Coccidioides genomic resources, we first discovered a new facet of genome organization in this system: spherule-gene islands, clusters of genes physically linked in the genome that exhibited specific mRNA induction in the spherule phase. Next, we surveyed copy-number variation genome-wide among strains of C. posadasii. Emerging from this catalog were spherule-gene islands with striking presence-absence differentiation between C. posadasii populations, a pattern expected from virulence factors subjected to different selective pressures across habitats. Finally, analyzing single-nucleotide differences across C. posadasii strains, we identified signatures of natural selection in spherule-expressed genes. Together, our data establish spherule-gene islands as candidate determinants of virulence and targets of selection in Coccidioides.

Fluconazole Failure in the Treatment of Coccidioidal Meningitis

INTRODUCTION

Coccidioidal meningitis (CM) is the most lethal form of disseminated coccidioidomycosis. Current guidelines recommend fluconazole as initial therapy but there has been a paucity of data regarding failure of fluconazole and optimal fluconazole dosage in the treatment of CM. We conducted this study to understand risk factors for fluconazole failure.

METHODS

We conducted a single-center retrospective chart review of patients diagnosed with coccidioidal meningitis between 1 January 1988 and 15 May 2021. Relevant demographic and clinical variables were collected, along with outcomes including treatment failure and death at any point. Univariate tests were conducted using the chi-squared goodness of fit test and analysis of variance.

RESULTS

Among 71 patients who began treatment for CM with fluconazole, 22 (31%) developed worsening meningitis at a median time of 206 days. Longer time from symptom onset to diagnosis of CM was a risk factor for fluconazole failure. Although the absolute failure rate of fluconazole starting dose of 400 mg daily was higher than that of 800 mg daily, the differences did not achieve statistical significance (p = 0.39).

CONCLUSION

Fluconazole failure is not uncommon in the treatment of CM. A dose of 800 mg daily was not superior to a dose of 400 mg daily. All patients on fluconazole for CM require close monitoring.

Breathing can be dangerous: Opportunistic fungal pathogens and the diverse community of the small mammal lung mycobiome

Human lung mycobiome studies typically sample bronchoalveolar lavage or sputum, potentially overlooking fungi embedded in tissues. Employing ultra-frozen lung tissues from biorepositories, we obtained fungal ribosomal RNA ITS2 sequences from 199 small mammals across 39 species. We documented diverse fungi, including common environmental fungi such as Penicillium and Aspergillus, associates of the human mycobiome such as Malassezia and Candida, and others specifically adapted for lungs (Coccidioides, Blastomyces, and Pneumocystis). Pneumocystis sequences were detected in 83% of the samples and generally exhibited phylogenetic congruence with hosts. Among sequences from diverse opportunistic pathogens in the Onygenales, species of Coccidioides occurred in 12% of samples and species of Blastomyces in 85% of samples. Coccidioides sequences occurred in 14 mammalian species. The presence of neither Coccidioides nor Aspergillus fumigatus correlated with substantial shifts in the overall mycobiome, although there was some indication that fungal communities might be influenced by high levels of A. fumigatus. Although members of the Onygenales were common in lung samples (92%), they are not common in environmental surveys. Our results indicate that Pneumocystis and certain Onygenales are common commensal members of the lung mycobiome. These results provide new insights into the biology of lung-inhabiting fungi and flag small mammals as potential reservoirs for emerging fungal pathogens.

Reactivation of Coccidioidomycosis in a Mouse Model of Asymptomatic Controlled Disease

The majority of human coccidioidomycosis infections are asymptomatic or self-limited but may have sequestered spherules in highly structured granulomas. Under immunosuppression, reactivation of fungal growth can result in severe disease. B6D2F1 mice asymptomatically infected with C. posadasii strain 1038 were immunosuppressed with dexamethasone (DXM) in drinking water. Treated mice died 16−25 days later, while untreated mice survived (p < 0.001). Flow cytometry of lung granulomas on days 5, 10, 15, and 20 of DXM treatment showed immune cell populations decreased 0.5−1 log compared with untreated mice though neutrophils and CD19+IgD−IgM− cells rebounded by day 20. Histopathology demonstrated loss of granuloma structure by day 5 and increasing spherules through day 20. On day 20, T-cells were nearly absent and disorganized pyogranulomatous lesions included sheets of plasma cells and innumerable spherules. Mice given DXM for 14 days then stopped (DXM stop) survived 6 weeks (9/10). Lung fungal burdens were significantly lower (p = 0.0447) than mice that continued treatment (DXM cont) but higher than untreated mice. Histopathologically, DXM stop mice did not redevelop controlled granulomas by sacrifice, though T-cells were densely scattered throughout the lesions. This demonstrates a mouse model suitable for further study to understand the immunologic components responsible for maintenance control of coccidioidomycosis.

Coccidioidomycosis Seroincidence and Risk among Military Personnel, Naval Air Station Lemoore, San Joaquin Valley, California, USA1

We conducted a retrospective cohort study that tested 2,000 US military personnel for Coccidioides antibodies in a disease-endemic region. The overall incidence of seroconversion was 0.5 cases/100 person-years; 12.5% of persons who seroconverted had illnesses requiring medical care. No significant association was found between demographic characteristics and seroconversion or disease.

Controversies in the Management of Central Nervous System Coccidioidomycosis

Central nervous system infection with Coccidioides spp is fatal if untreated, and complications occur even when therapy is directed by experienced clinicians. We convened a panel of clinicians experienced in the management of coccidioidal meningitis to summarize current controversies and provide consensus for the management of this difficult infection.

Disseminated coccidioidomycosis in immunocompetent patients in non-endemic areas: a case series and literature review

Coccidioidomycosis is caused by the dimorphic fungi Coccidioides species which is endemic in the Western hemisphere. Reports on the characteristics of travel-related disseminated coccidioidomycosis in immunocompetent patients are rare, especially in non-endemic regions. The multifaceted symptoms of this condition present a diagnostic challenge to clinicians. This study aimed to review immunocompetent patients diagnosed with disseminated coccidioidomycosis in a tertiary hospital in Eastern China and other non-endemic areas, and to emphasize the importance of combining travel history with clinical manifestations and proper diagnostic examinations. This study retrospectively reviewed a case series of disseminated coccidioidomycosis diagnosed in an academic hospital in Eastern China. We conducted a global literature review of disseminated coccidioidomycosis in immunocompetent patients with travel history. We identified six patients in our case series and reviewed 42 cases in the literature. Travel history included Mexico, Arizona, California, and regions of low endemicity. Extrapulmonary sites of infection, which presented with diverse signs and symptoms, involved the skin and soft tissue, musculoskeletal system, lymph nodes, and central nervous system. Misdiagnoses and diagnostic delays were common. Next-generation sequencing substantially promoted precise diagnosis in our series. The overall prognosis for immunocompetent individuals was positive, mainly benefited from long-term azole therapies. The patients that succumbed had either central nervous system involvement or multiorgan dissemination. Progressive pneumonia with varied symptoms and travel history should alert healthcare professionals in non-endemic areas to consider the possibility of Coccidioides species infection. We recommend detailed history-taking and hypothesis-free detection of pathogens for cases with diagnostic delay.

PM10 and Other Climatic Variables Are Important Predictors of Seasonal Variability of Coccidioidomycosis in Arizona

Coccidioidomycosis (Valley fever) is a disease caused by the fungal pathogens Coccidioides immitis and Coccidioides posadasii that are endemic to the southwestern United States and parts of Mexico and South America. Throughout the range where the pathogens are endemic, there are seasonal patterns of infection rates that are associated with certain climatic variables. Previous studies that looked at annual and monthly relationships of coccidioidomycosis and climate suggest that infection numbers are linked with precipitation and temperature fluctuations; however, these analytic methods may miss important nonlinear, nonmonotonic seasonal relationships between the response (Valley fever cases) and explanatory variables (climate) influencing disease outbreaks. To improve our current knowledge and to retest relationships, we used case data from three counties of high endemicity in southern Arizona paired with climate data to construct a generalized additive statistical model that explores which meteorological parameters are most useful in predicting Valley fever incidence throughout the year. We then use our model to forecast the pattern of Valley fever cases by month. Our model shows that maximum monthly temperature, average PM10, and total precipitation 1 month prior to reported cases (lagged model) were all significant in predicting Valley fever cases. Our model fits Valley fever case data in the region of endemicity of southern Arizona and captures the seasonal relationships that predict when the public is at higher risk of being infected. This study builds on and retests relationships described by previous studies regarding climate variables that are important for predicting risk of infection and understanding this fungal pathogen. IMPORTANCE The inhalation of environmental infectious propagules from the fungal pathogens Coccidioides immitis and Coccidioides posadasii by susceptible mammals can result in coccidioidomycosis (Valley fever). Arizona is known to be a region where the pathogen is hyperendemic, and reported cases are increasing throughout the western United States. Coccidioides spp. are naturally occurring fungi in arid soils. Little is known about ecological factors that influence the growth of these fungi, and a higher environmental burden may result in increases in human exposure and therefore case rates. By examining case and climate data from Arizona and using generalized additive statistical models, we were able to examine the relationship between disease outbreaks and climatic variables and predict seasonal time points of increased infection risk.

Coccidioidomycosis: A Contemporary Review

Coccidioidomycosis, colloquially known as Valley Fever, is an invasive dimorphic fungal infection caused by Coccidioides immitis and C. posadasii. The fungi are found in the arid desert soils of the southwestern US, as well as in parts of Mexico and Central and South America. Acquisition is typically via inhalation of arthroconidia which become airborne after both natural (e.g., earthquakes, dust storms, and fires) and human-related events (e.g., military maneuvers, recreational activities, agriculture, and construction). The incidence of infection in increasing likely a result of both climatic and populational changes. Further, the recognized geographic distribution of Coccidioides spp. is expanding, as cases are being diagnosed in new areas (e.g., eastern Washington, Oregon, and Utah). Most coccidioidal infections are asymptomatic (60%); however, approximately one-third develop a pulmonary illness which is a leading cause of community-acquired pneumonia in highly endemic areas. Uncommonly (0.5–2% of cases), the infection disseminates to extrapulmonary locations (e.g., skin, bones/joints, and the central nervous system), and is most commonly seen among persons with cellular immunodeficiencies (e.g., transplant recipients, HIV, and pregnancy) and non-Caucasian races (especially African Americans and Filipinos). The diagnosis of coccidioidomycosis requires astute clinical suspicion and laboratory findings, including positive serology, cultures, and/or histopathology results. Treatment is warranted among persons with pneumonia who have risk factors for complicated disease and among those with extrapulmonary disease. Novel antifungals with improved fungicidal activity and rapidity of action with fewer side effects and drug interactions are needed. Preventive strategies (e.g., education regarding the disease, dust avoidance, mask wearing, including among select groups, antifungal prophylaxis, and surveillance laboratory testing) are advised for residents and travelers to endemic areas. Currently, no preventive vaccine is available. Coccidioidomycosis has been recognized for over a century, and an expanding wealth of knowledge has been gained regarding this emerging infectious disease which will be reviewed here.

Agricultural practices drive biological loads, seasonal patterns and potential pathogens in the aerobiome of a mixed-land-use dryland

Air carries a diverse load of particulate microscopic biological matter in suspension, either aerosolized or aggregated with dust particles, the aerobiome, which is dispersed by winds from sources to sinks. The aerobiome is known to contain microbes, including pathogens, as well as debris or small-sized propagules from plants and animals, but its variability and composition has not been studied comprehensibly. To gain a dynamic insight into the aerobiome existing over a mixed-use dryland setting, we conducted a biologically comprehensive, year-long survey of its composition and dynamics for particles less than 10 μm in diameter based on quantitative analyses of DNA content coupled to genomic sequencing. Airborne biological loads were more dependent on seasonal events than on meteorological conditions and only weakly correlated with dust loads. Core aerobiome species could be understood as a mixture of high elevation (e.g. Microbacteriaceae, Micrococcaceae, Deinococci), and local plant and soil sources (e.g. Sphingomonas, Streptomyces, Acinetobacter). Despite the mixed used of the land surrounding the sampling site, taxa that contributed to high load events were largely traceable to proximal agricultural practices like cotton and livestock farming. This included not only the predominance of specific crop plant signals over those of native vegetation, but also that of their pathogens (bacterial, viral and eukaryotic). Faecal bacterial loads were also seasonally important, possibly sourced in intensive animal husbandry or manure fertilization activity, and this microbial load was enriched in tetracycline resistance genes. The presence of the native opportunistic pathogen, Coccidioides spp., by contrast, was detected only with highly sensitive techniques, and only rarely. We conclude that agricultural activity exerts a much stronger influence that the native vegetation as a mass loss factor to the land system and as an input to dryland aerobiomes, including in the dispersal of plant, animal and human pathogens and their genetic resistance characteristics.

Factors Influencing Distribution of Coccidioides immitis in Soil, Washington State, 2016

Coccidioides immitis and Coccidioides posadasii are causative agents of Valley fever, a serious fungal disease endemic to regions with hot, arid climate in the United States, Mexico, and Central and South America. The environmental niche of Coccidioides spp. is not well defined, and it remains unknown whether these fungi are primarily associated with rodents or grow as saprotrophs in soil. To better understand the environmental reservoir of these pathogens, we used a systematic soil sampling approach, quantitative PCR (qPCR), culture, whole-genome sequencing, and soil chemical analysis to identify factors associated with the presence of C. immitis at a known colonization site in Washington State linked to a human case in 2010. We found that the same strain colonized an area of over 46,000 m² and persisted in soil for over 6 years. No association with rodent burrows was observed, as C. immitis DNA was as likely to be detected inside rodent holes as it was in the surrounding soil. In addition, the presence of C. immitis DNA in soil was correlated with elevated levels of boron, calcium, magnesium, sodium, and silicon in soil leachates. We also observed differences in the microbial communities between C. immitis-positive and -negative soils. Our artificial soil inoculation experiments demonstrated that C. immitis can use soil as a sole source of nutrients. Taken together, these results suggest that soil parameters need to be considered when modeling the distribution of this fungus in the environment.

IMPORTANCE Coccidioidomycosis is considered a highly endemic disease for which geographic range is likely to expand from climate change. A better understanding of the ecological niche of Coccidioides spp. is essential for generating accurate distribution maps and predicting future changes in response to the changing environment. Our study used a systematic sampling strategy, advanced molecular detection methods, and soil chemical analysis to identify environmental factors associated with the presence of C. immitis in soil. Our results demonstrate the fungus can colonize the same areas for years and is associated with chemical and microbiological soil characteristics. Our results suggest that in addition to climate parameters, soil characteristics need to be considered when building habitat distribution models for this pathogen.

Demonstration of N,N-Dimethyldithiocarbamate as a Copper-Dependent Antibiotic against Multiple Upper Respiratory Tract Pathogens

Transition metals are necessary cofactors and structural elements in living systems. Exposure to high concentrations of biologically important transition metals, such as zinc and copper, results in cell toxicity. At the infection site, the immune system deploys metal sorbent proteins (e.g., lactoferrin and calprotectin) to starve pathogens of necessary metals (such as iron), while phagocytes expose engulfed pathogens to high levels of other metals, such as copper and zinc. The opportunistic pathogen Streptococcus pneumoniae (the pneumococcus) encounters macrophages during initial and protracted infections. The pneumococcus employs a copper export pathway, which improves colonization and persistent infection of the nasopharynx and the upper respiratory tract. Because copper is tightly regulated in the host, we instead sought to leverage the localized power of nutritional immunity by identifying small molecules with copper-dependent toxicity (CDT) through a targeted screen of compounds for antibiotic efficacy. We chose to include dithiocarbamates, based on the copper synergy observed in other organisms with 1-(diethylthiocarbamoyldisulfanyl)-N,N-diethyl-methanethioamide (tetraethylthiuram disulfide, disulfiram). We observed CDT of some dithiocarbamates in S. pneumoniae. Only N,N-dimethyldithiocarbamate (DMDC) was consistently toxic across a range of concentrations with copper both in vitro and in vivo against the pneumococcus. We also observed various degrees of CDT in vitro using DMDC in Staphylococcus aureus, Coccidioides posadasii, and Schistosoma mansoni. Collectively, we demonstrate that the compound DMDC is a potent bactericidal compound against S. pneumoniae with antimicrobial efficacy against bacterial and fungal pathogens.

IMPORTANCE With the rise of antibiotic resistance, approaches that add new antimicrobials to the current repertoire are vital. Here, we investigate putative and known copper ionophores in an attempt to intoxicate bacteria and use ionophore/copper synergy, and we ultimately find success with N,N-dimethyldithiocarbamate (DMDC). We show that DMDC has in vitro efficacy in a copper-dependent manner and kills pathogens across three different kingdoms, Streptococcus pneumoniae, Coccidioides posadasii, and Schistosoma mansoni, and in vivo efficacy against S. pneumoniae. As such, dithiocarbamates represent a new potential class of antimicrobials and thus warrant further mechanistic investigation.

Nikkomycin Z against Disseminated Coccidioidomycosis in a Murine Model of Sustained-Release Dosing

Nikkomycin Z (nikZ) is a chitin synthase inhibitor. Efficacy against Coccidioides has been demonstrated in animal models of pulmonary or brain infection. Its short half-life in mice and in humans would necessitate divided daily dosing. We assayed nikZ efficacy in disseminated coccidioidomycosis (in a reduction of CFU design) and whether sustained release might be useful. Mice were challenged intravenously with low or high arthroconidial inocula. Fluconazole, clinically the most commonly used anticoccidioidal drug, was compared (gavage) at high dose to a dose range of nikZ administered intraperitoneally or, to mimic sustained release, administered continuously in drinking water. Therapy was given for 5 days. In vitro, both fluconazole and nikZ inhibited the isolate studied; nikZ was fungicidal. Oral nikZ therapy gave similar results to intraperitoneal nikZ and sterilized infection in most animals after low-inoculum challenge. In both challenges, oral nikZ produced greater reduction of CFU in organs (lung, liver, and spleen) than fluconazole. Oral nikZ doses of ≥200 mg/kg of body weight/day were particularly effective in all organs and were well tolerated. This efficacy occurred even though, after severe challenge, mice had reduced water intake, resulting in ingesting less than the desired dose, particularly initially after infection. This study shows, for the first time, efficacy of nikZ against disseminated coccidioidomycosis. Efficacy was shown after challenges producing different levels of severity of disease. This study also suggests the likely benefits of developing an extended release formulation supplying continuous systemic concentrations of nikZ.

Epidemiology, Clinical Features, and Outcomes of Coccidioidomycosis, Utah, 2006-2015

On the basis of a 1957 geographic Coccidioides seropositivity survey, 3 counties in southwestern Utah, USA, were considered coccidioidomycosis-endemic, but there has been a paucity of information on the disease burden in Utah since. We report findings from a recent clinical and epidemiologic study of coccidioidomycosis in Utah. To describe clinical characteristics, we identified all coccidioidomycosis cases in an integrated health system in the state during 2006-2015. For epidemiologic analysis, we used cases reported to the Utah Department of Health during 2009-2015. Mean state incidence was 1.83 cases/100,000 population/year. Washington County, in southwestern Utah, had the highest incidence, 17.2 cases/100,000 population/year. In a generalized linear model with time as a fixed effect, mean annual temperature, population, and new construction were associated with regional variations in incidence. Using these variables in a spatiotemporal model, we estimated the adjusted regional variation by county to predict areas where Coccidioides infections might increase.

Pericarditis and Sacroiliitis in a World Traveler

A 65-year-old immunocompromised woman presented with progressive dyspnea and sacroiliac joint pain. Cardiac magnetic resonance showed abnormal right ventricular filling with septal bounce and abnormal pericardial enhancement, suggestive of constrictive pericarditis. Cultures from pericardium following pericardiectomy grew Coccidioides immitis. She was diagnosed with coccidioidomycosis and responded to pericardiectomy and amphotericin. (Level of Difficulty: Intermediate.)

A Review of Coccidioides Research, Outstanding Questions in the Field, and Contributions by Women Scientists

Purpose of Review

Coccidioidomycosis is an infectious disease that gained clinical significance in the early 20th century. Many of the foundational contributions to coccidioidomycosis research, including the discovery of the fungal disease agent, Coccidioides spp., were made by women. We review recent progress in Coccidioides research and big questions remaining in the field, while highlighting some of the contributions from women.

Recent Findings

New molecular-based techniques provide a promising method for detecting Coccidioides, which can help determine the dominate reservoir host and ideal environmental conditions for growth. Genetic and genomic analyses have allowed an understanding of population structure, species level diversity, and evolutionary histories. We present a current, comprehensive genome list, where women contributed many of these entries. Several efforts to develop a coccidioidomycosis vaccine are underway.

Summary

Women continue to pioneer research on Coccidioides, including the relationships between the fungi and the environment, genetics, and clinical observations. Significant questions remain in the field of Coccidioides, including the main host reservoir, the relationships between genotypic and phenotypic variation, and the underlying cause for chronic clinical coccidioidomycosis cases.

Mitochondrial genomes of the human pathogens Coccidioides immitis and Coccidioides posadasii

Fungal mitochondrial genomes encode genes involved in crucial cellular processes, such as oxidative phosphorylation and mitochondrial translation, and the molecule has been used as a molecular marker for population genetics studies. Coccidioides immitis and C. posadasii are endemic fungal pathogens that cause coccidioidomycosis in arid regions across both American continents. To date, approximately 150 Coccidioides isolates have been sequenced to infer patterns of variation in nuclear genomes. However, less attention has been given to the mitochondrial genomes of Coccidioides. In this report, we describe the assembly and annotation of mitochondrial reference genomes for two representative strains of C. posadasii and C. immitis, as well as assess population variation among 77 selected genomes. The sizes of the circular-mapping molecules are 68.2 Kb in C. immitis and 75.1 Kb in C. posadasii. We identify 14 mitochondrial protein-coding genes common to most fungal mitochondria, which are largely syntenic across different populations and species of Coccidioides. Both Coccidioides species are characterized by a large number of group I and II introns, harboring twice the number of elements as compared to closely related Onygenales. The introns contain complete or truncated ORFs with high similarity to homing endonucleases of the LAGLIDADG and GIY-YIG families. Phylogenetic comparisons of mitochondrial and nuclear genomes show extensive phylogenetic discordance suggesting that the evolution of the two types of genetic material is not identical. This work represents the first assessment of mitochondrial genomes among isolates of both species of Coccidioides, and provides a foundation for future functional work.

More than Valley Fever: Pulmonary Actinomycosis and Coccidioidomycosis Co-infection in a Patient

Pulmonary coccidioidomycosis and pulmonary actinomycosis are unheard of as co-pathogens. Infection with these organisms on their own can mimic lung cancer, thus presenting a diagnostic challenge. We present the case of a 75-year-old woman presenting with haemoptysis with a chest CT chest finding of a lung mass suggestive of lung cancer. A diagnosis of concomitant infection by Coccidioides posadasii/immitis and Actinomyces odontolyticus was made based on culture and histopathology results. The patient was successfully treated with a combination of antifungal and antibacterial therapy. This is the first reported case of co-infection by these two microorganisms.

LEARNING POINTS

Pulmonary coccidioidomycosis and pulmonary actinomycosis can mimic lung cancer.The diagnosis of infection by Coccidioides posadasii/immitis and Actinomyces odontolyticus is best obtained by histopathology and tissue culture.Treatment comprises a combination of oral azoles and a beta-lactam antibiotic for a total of 12 months.

Risk for Coccidioidomycosis among Hispanic Farm Workers, California, USA, 2018

To determine occupational risk factors for coccidioidomycosis among adult Hispanic outdoor agricultural workers in California, USA, we conducted a case-control study of workers seen at the Kern County medical facility and referred to the public health laboratory for coccidioidomycosis serologic testing. Participants completed an interviewer-administered health and work questionnaire. Among 203 participants (110 case-patients with positive and 93 controls with negative serologic results), approximately half were women, and more than three quarters were born in Mexico. Associated with coccidioidomycosis were self-reported dust exposure and work with root and bulb vegetable crops. A protective factor was leaf removal, an activity associated with grape cultivation. We conclude that subjective dust exposure and work with root and bulb vegetable crops are associated with increased risk for coccidioidomycosis among Hispanic farm workers. The agricultural industry should evaluate and promote dust-reduction measures, including wetting soil and freshly harvested products.

A Chronic Murine Disease Model of Coccidioidomycosis Using Coccidioides posadasii, Strain 1038

Murine infections with most Coccidioides spp. strains are lethal by 3 weeks, limiting the study of immune responses. Coccidioides posadasii, strain 1038 (Cp1038), while slowly lethal, resulted in protracted survival of C57BL/6 (B6) mice. In resistant (B6D2)F1/J mice, lung fungal burdens stabilized by week 4 without progression through week 16, better modeling human coccidioidal infections after their immunologic control. Immunodeficient tumor necrosis factor (Tnf) α knockout (KO) and interferon (Ifn) γ receptor 1 (Ifn-γr1) KO mice survived a median of 22.5 and 34 days, compared with 70 days in B6 mice (P = .001 and P < .01, respectively), though 14-day lung fungal burden studies showed little difference between Ifn-γr1 KO and B6 mice. B6 mice showed peak concentrations of key inflammatory lung cytokines, including interleukin 6, 23, and 17A, Tnf-α, and Ifn-γ, only after 4 weeks of infection. The slower progression in B6 and the acquired fungal burden stability in B6D2 mice after Cp1038 infection greatly increases the array of possible immunologic studies.