Epidemiology of Acute Coccidioidomycosis with Erythema Nodosum ("San Joaquin" or "Valley Fever")

Access to Urgent Care Practices Improves Understanding and Management of Endemic Coccidioidomycosis: Maricopa County, Arizona, 2018-2023

BACKGROUND

Coccidioidomycosis within endemic regions is often undiagnosed because appropriate testing is not performed. A dashboard was developed to provide information about the prevalence of coccidioidomycosis throughout the year.

METHODS

Banner Urgent Care Service has many clinics within Maricopa County, Arizona, a highly endemic region for coccidioidomycosis. All clinic visits and subset analyses for patients with International Classification of Diseases, Tenth Revision codes for pneumonia (J18.*) or erythema nodosum (L52) during 2018-2024 were included. Tabulated were daily frequencies of visits, pneumonia and erythema nodosum coding, coccidioidal testing, and test results. Banner Urgent Care Services' counts of monthly coccidioidomycosis diagnoses were compared with those of confirmed coccidioidomycosis cases reported to Maricopa County Department of Public Health.

RESULTS

Monthly frequencies of urgent care coccidioidomycosis diagnoses strongly correlated with public health coccidioidomycosis case counts (r = 0.86). Testing frequency for coccidioidomycosis correlated with overall pneumonia frequency (r = 0.52). The proportion of pneumonia due to coccidioidomycosis varied between <5% and >45% within and between years. Coccidioidomycosis was a common cause of erythema nodosum (65%; 95% confidence interval, 45%-67%) and independent of pneumonia. Over half of Banner Urgent Care Services' coccidioidomycosis diagnoses were coded for neither pneumonia nor erythema nodosum.

CONCLUSION

Data provided by the coccidioidomycosis dashboard can assist urgent care practitioners in knowing when coccidioidomycosis is prevalent in the community. Patients with exposure to endemic coccidioidomycosis who develop erythema nodosum or pneumonia should routinely be tested for coccidioidomycosis. Data from private health care organizations can augment surveillance of diseases important to public health.

Improving Early Recognition of Coccidioidomycosis in Urgent Care Clinics: Analysis of an Implemented Education Program

Background

Only 0.2% of coccidioidomycosis (CM) diagnoses were made in patients (pts) with pneumonia (PNA) in urgent care (UC), because they were not being tested for CM. Our objective in this study was to improve CM testing rates.

Methods

This was a time series of clinician practice before and after an intervention that occurred at UC clinics in Phoenix and Tucson Arizona. All patients in UC were >18 years old. We included information about CM in periodic educational activities for clinicians. Coccidioidal serologic testing (CST), CST results, and their relation to International Classification of Diseases, Tenth Revision (ICD-10) codes were extracted from medical records.

Results

Urgent care received 2.1 million visits from 1.5 million patients. The CST orders per 10⁴ visits increased from 5.5 to 19.8 (P < .0001). Percentage positive CSTs were highest for August, November, and December (17.0%) versus other months (10.6%). Positive CSTs were associated with PNA ICD-10 codes, and, independently, for Erythema nodosum (EN) which had the highest positivity rate (61.4%). Testing of PNA pts increased on first visits and on second visits when the first CST was negative. Yearly rates of PNA due to CM ranged from 17.3% to 26.0%. Despite this improvement, CST was still not done for over three quarters of pts with PNA. This was a noncomparative study.

Conclusions

Routine quality improvement activities have significantly but only partially improved rates of testing pts with PNA for CM in UC clinics located in a highly endemic area. Innovative strategies may be needed to improve current practice. Also in our region, EN, independent of PNA, is a strong predictor of CM.

Natural history of pulmonary coccidioidomycosis: Further examination of the VA-Armed Forces Database

There are still many limitations related to the understanding of the natural history of differing forms of coccidioidomycosis (CM), including characterizing the spectrum of pulmonary disease. The historical Veterans Administration-Armed Forces database, recorded primarily before the advent of antifungal therapy, presents an opportunity to characterize the natural history of pulmonary CM. We performed a retrospective cohort study of 342 armed forces service members who were diagnosed with pulmonary CM at VA facilities between 1955 to 1958, followed through 1966, who did not receive antifungal therapy. Patients were grouped by predominant pulmonary finding on chest radiographs. The all-cause mortality was low for all patients (4.6%). Cavities had a median size of 3-3.9 cm (IQR: 2-2.9-4-4.9 cm), with heterogeneous wall thickness and no fluid level, while nodules had a median size of 1-1.19 cm (Interquartile range [IQR] 1-1.9-2-2.9 cm) and sharp borders. The majority of cavities were chronic (85.6%), and just under half were found incidentally. Median complement fixation titers in both the nodular and cavitary groups were negative, with higher titers in the cavitary group overall. This retrospective cohort study of non-disseminated coccidioidomycosis, the largest to date, sheds light on the natural history, serologic markers, and radiologic characteristics of this understudied disease. These findings have implications for the evaluation and management of CM.

Coccidioides Species: A Review of Basic Research: 2022

Coccidioides immitis and posadasii are closely related fungal species that cause coccidioidomycosis. These dimorphic organisms cause disease in immunocompetent as well as immunocompromised individuals and as much as 40% of the population is infected in the endemic area. Although most infections resolve spontaneously, the infection can be prolonged and, in some instances, fatal. Coccidioides has been studied for more than 100 years and many aspects of the organism and the disease it causes have been investigated. There are over 500 manuscripts concerning Coccidioides (excluding clinical articles) referenced in PubMed over the past 50 years, so there is a large body of evidence to review. We reviewed the most accurate and informative basic research studies of these fungi including some seminal older studies as well as an extensive review of current research. This is an attempt to gather the most important basic research studies about this fungus into one publication. To focus this review, we will discuss the mycology of the organism exclusively rather than the studies of the host response or clinical studies. We hope that this review will be a useful resource to those interested in Coccidioides and coccidioidomycosis.

Sex Differences in the Susceptibility to Coccidioidomycosis

To assess sex-specific differences in coccidioidomycosis, a retrospective analysis of human patients, nonhuman primates, and veterinary patients (including the neutered status of the animal) was performed. We found higher rates of infection and severity in males. This observed increased infection risk suggests deeper biological underpinnings than solely occupational/exposure risks.

No Consistent Link Between Dust Storms and Valley Fever (Coccidioidomycosis)

Dust storms, such as those associated with haboobs and strong regional winds, are frequently assumed to cause increases in cases of Valley fever (coccidioidomycosis). The disease is caused by inhaling arthroconidia of Coccidioides fungi that, after being disturbed from semi-desert subsoil, have become airborne. Fungal arthroconidia can be transported in low-wind conditions as well as in individual dust events, but there is no reliable evidence that all or most dust storms consistently lead to subsequent increases in coccidioidomycosis cases. Following a review of the relevant literature, this study examines the relationship between dust storms and coccidioidomycosis cases to determine if there is a consistent and general association between them. All recorded dust storms from 2006 to 2020 in and near the Phoenix area of Maricopa County, Arizona and the Bakersfield area of Kern County, California were used in a compositing analysis (superposed epoch analysis) of subsequent coccidioidomycosis cases in each area. Analyses of monthly and weekly disease case data showed no statistical differences in the patterns of coccidioidomycosis cases following dust storms versus non-dust storm conditions, for the entire data set as well as for seasonal subsets of the data. This study thoroughly analyzes post-dust storm coccidioidomycosis cases for a large set of dust storms, and it confirms and expands upon previous literature, including a recent study that measured airborne arthroconidia and found no consistent links connecting wind and dust conditions to increases in coccidioidomycosis.

Disseminated Coccidioidomycosis Presenting as Fever of Unknown Origin and Erythema Nodosum in a 3-Year-Old Child

Disseminated coccidioidomycosis is a disease caused by Coccidioides species, fungi endemic to the southwestern United States. We present here an uncommon case of a young child with erythema nodosum and fever of unknown origin, found to have the infection. While more common in adults, coccidioidomycosis should be considered in all patients with erythema nodosum.

Host Response to Coccidioides Infection: Fungal Immunity

Coccidioidomycosis is a fungal, respiratory disease caused by Coccidioides immitis and Coccidioides posadasii. This emerging infectious disease ranges from asymptomatic to pulmonary disease and disseminated infection. Most infections are cleared with little to no medical intervention whereas chronic disease often requires life-long medication with severe impairment in quality of life. It is unclear what differentiates hosts immunity resulting in disease resolution versus chronic infection. Current understanding in mycology-immunology suggests that chronic infection could be due to maladaptive immune responses. Immunosuppressed patients develop more severe disease and mouse studies show adaptive Th1 and Th17 responses are required for clearance. This is supported by heightened immunosuppressive regulatory responses and lowered anti-fungal T helper responses in chronic Coccidioides patients. Diagnosis and prognosis is difficult as symptoms are broad and overlapping with community acquired pneumonia, often resulting in misdiagnosis and delayed treatment. Furthermore, we lack clear biomarkers of disease severity which could aid prognosis for more effective healthcare. As the endemic region grows and population increases in endemic areas, the need to understand Coccidioides infection is becoming urgent. There is a growing effort to identify fungal virulence factors and host immune components that influence fungal immunity and relate these to patient disease outcome and treatment. This review compiles the known immune responses to Coccidioides spp. infection and various related fungal pathogens to provide speculation on Coccidioides immunity.

Charles Edward Smith: Coccidioidomycologist and public health leader

Although Charles Edward Smith did not discover coccidioidomycosis, he defined the disease through his infatigueable studies of the epidemiology, clinical findings, and immunology of this infection. He became its preeminent authority. He also had an important role in the development of public health, and for the last 16 years of his life he was the Dean of the School of Public Health at the University of California at Berkeley, where he was a revered and energetic leader.

Early Events in Coccidioidomycosis

Since its description nearly 130 years ago, hundreds of studies have deepened our understanding of coccidioidomycosis, also known as valley fever (VF), and provided useful diagnostic tests and treatments for the disease caused by the dimorphic fungi Coccidioides spp. In general, most of the literature has addressed well-established infections and has described patients who have experienced major complications. In contrast, little attention has been given to the earliest consequences of the pathogen-host interaction and its implications for disease manifestation, progression, and resolution. The purpose of this review is to highlight published studies on early coccidioidomycosis, identify gaps in our knowledge, and suggest new or former research areas that might be or remain fertile ground for insight into the early stages of this invasive fungal disease.

Host-Pathogen Interactions in Coccidioidomycosis: Prognostic Clues and Opportunities for Novel Therapies

PURPOSE

Coccidioidomycosis (CM) is a systemic fungal disease caused by the dimorphic fungi Coccidioides immitis and Coccidioides posadasii. In its endemic areas of the United States, CM is growing as a public health challenge with a marked increase in incidence in the last 15 years. Although Coccidioides infection is asymptomatic in most cases, symptomatic pulmonary disease occurs in ~40% and disseminated coccidioidomycosis (DCM) occurs in ~1% of previously healthy children and adults. DCM is markedly more common in immunocompromised people, who often experience life-threatening disease despite use of antifungal medications. Although options for antifungal therapy have improved, lifelong therapy is needed for those who develop coccidioidal meningitis. The purpose of this article was to review the state of antifungal therapy and recent studies of host-pathogen interactions in CM in light of advances in immunomodulatory therapy.

METHODS

The study included a review of PubMed and abstracts of the Coccidioidomycosis Study Group (years 2000-2019).

FINDINGS

Current therapy for CM relies upon azole and polyene antifungal agents. Murine models and studies of DCM in patients with monogenic primary immunodeficiency states and acquired immunodeficiency have revealed the importance of both innate and adaptive immune responses in the control of infections with Coccidioides species. In particular, defects in sensing of fungi and induction of cellular immune responses have been frequently reported. More recently, polymorphisms in key signaling pathways and in the generation of Th17 and Th1 immune responses have been linked with DCM.

IMPLICATIONS

Antifungal therapy is sufficient to control disease in most cases of CM, but treatment failure occurs in cases of severe pulmonary disease and nonmeningeal disseminated disease. Lifelong therapy is recommended for meningitis in view of the very high risk of recurrence. Corticosteroid therapy is advised by some experts for severe pulmonary disease and for some neurologic complications of DCM. DCM is only rarely the result of a severe monogenic immunodeficiency. Case studies suggest that reorienting cellular immune responses or augmenting effector immune responses may help resolve DCM. Systematic investigation of immunotherapy for coccidioidomycosis is advisable and may help to address the recent marked increase in reports of the disease in endemic areas.

Management of asymptomatic coccidioidomycosis in patients with rheumatic diseases

Coccidioidomycosis is an endemic fungal infection common in the southwestern United States. Some rheumatology clinics periodically screen patients with coccidioidal serology, resulting in the identification of patients who are serologically positive but without clinical symptoms. The management of such patients is unclear. A retrospective study was conducted between 2007 and 2015 at two arthritis centers in Tucson, Arizona. The asymptomatic patients were identified who were receiving disease-modifying antirheumatic agents and had a positive coccidioidal serology. Serological testing including IgM and IgG was performed by enzyme immunoassay (EIA), immunodiffusion (IDTP and IDCF), or complement fixation. Out of 71 patients who were identified with positive coccidioidal serologies, 19 were asymptomatic. 18/19 patients continued antirheumatic therapy, 13 without interruption. 13/19 patients received no antifungal treatment, including 10 who remained on antirheumatic treatment. The other six were started on fluconazole, ranging from 8 to 73 months (median 30.5 months). After a median follow-up of 43 months, no patient developed clinically active coccidioidomycosis. Overall, 14 had only a positive EIA serological test. These results suggest that continued antirheumatic therapy is safe in asymptomatic patients with positive coccidioidal serological tests and that routine implementation of antifungal treatment may not always be warranted. The findings also raise concern regarding the utility of routine serological testing of asymptomatic patients residing in the coccidioidal endemic area, mainly using the EIA test.

Coccidioides ecology and genomics

Although the natural history and ecology of Coccidioides spp. have been studied for over 100 years, many fundamental questions about this fungus remain unanswered. Two of the most challenging aspects of the study of Coccidioides have been the undefined ecological niche and the outdated geographic distribution maps dating from midcentury. This review details the history of Coccidioides ecological research, and discusses current strategies and advances in understanding Coccidioides genetics and ecology.

The endozoan, small-mammal reservoir hypothesis and the life cycle of Coccidioides species

The prevailing hypothesis concerning the ecology of Coccidioides immitis and C. posadasii is that these human pathogenic fungi are soil fungi endemic to hot, dry, salty regions of the New World and that humans and the local, small-mammal fauna are only accidental hosts. Here we advance an alternative hypothesis that Coccidioides spp. live in small mammals as endozoans, which are kept inactive but alive in host granulomas and which transform into spore-producing hyphae when the mammal dies. The endozoan hypothesis incorporates results from comparative genomic analyses of Coccidioides spp. and related taxa that have shown a reduction in gene families associated with deconstruction of plant cell walls and an increase in those associated with digestion of animal protein, consistent with an evolutionary shift in substrate from plants to animals. If true, the endozoan hypothesis requires that models of the prevalence of human coccidioidomycosis account not only for direct effects of climate and soil parameters on the growth and reproduction of Coccidioides spp. but also consider indirect effects on these fungi that come from the plants that support the growth and reproduction of the small mammals that, in turn, support these endozoic fungi.

Coccidioidomycosis Outbreaks, United States and Worldwide, 1940-2015

Coccidioidomycosis causes substantial illness and death in the United States each year. Although most cases are sporadic, outbreaks provide insight into the clinical and environmental features of coccidioidomycosis, high-risk activities, and the geographic range of Coccidioides fungi. We identified reports published in English of 47 coccidioidomycosis outbreaks worldwide that resulted in 1,464 cases during 1940–2015. Most (85%) outbreaks were associated with environmental exposures; the 2 largest outbreaks resulted from an earthquake and a large dust storm. More than one third of outbreaks occurred in areas where the fungus was not previously known to be endemic, and more than half of outbreaks involved occupational exposures. Coccidioidomycosis outbreaks can be difficult to detect and challenging to prevent given the unknown effectiveness of environmental control methods and personal protective equipment; therefore, increased awareness of coccidioidomycosis outbreaks is needed among public health professionals, healthcare providers, and the public.

From hidden outbreaks to epidemic emergencies: the threat associated with neglecting emerging pathogens

Not all infectious disease outbreaks undergo full epidemiological investigations. In certain situations, the resultant lack of knowledge has led to the development of epidemics and public health emergencies. This review will examine six emerging pathogens including their history, present status, and potential to expand to epidemics. Recommendations to improve our understanding of these hidden outbreaks and others also will be provided in the context of health systems policy.

Erythema Sweetobullosum: A Reactive Cutaneous Manifestation of Coccidioidomycosis

Reactive cutaneous coccidioidal skin manifestations are commonly noticed during the early stage of coccidioidomycosis. These skin lesions are devoid of any active coccidioidal organism, and the immune trigger mechanisms are not elucidated. We describe 6 cases of unusual reactive cutaneous coccidioidal manifestation, characterized by painful vesiculobullous lesions known as erythema sweetobullosum. The biopsy of the lesions revealed neutrophilic dermatosis with inflammatory cells resulting in a cleft and elevation of the most superficial layer of the skin forming a bulla. The reactive cutaneous lesion is self-limited and requires no specific therapy.

Evaluation of Amphotericin B Lipid Formulations for Treatment of Severe Coccidioidomycosis

Patients with severe coccidioidomycosis infections are often treated with either amphotericin B lipid complex (ABLC) or liposomal amphotericin B (L-AmB). Outcome data with these agents in severe coccidioidomycosis cases are currently lacking. The purpose of this study is to evaluate the efficacy and toxicity of ABLC and L-AmB in treating severe coccidioidomycosis. A retrospective pre-post study design was employed. Chart reviews were completed from 1 January 2005 to 31 December 2014 for all patients who received lipid-based amphotericin B. Inclusion criteria included having a follow-up complement fixation (CF) titer or a treatment emergent adverse event (TEAE) prior to follow-up. Patients with meningeal involvement and pregnant patients were excluded. Treatment outcomes were assessed based on documented completion of therapy as well on symptoms, complement fixation titer, and changes to laboratory monitoring parameters. A total of 108 patients were identified, 69 of whom met the inclusion criteria. There were no statistical differences in demographics or disease burden in those that received ABLC and those that received L-AmB, except that those who received L-AmB were more likely to have previously diagnosed chronic kidney disease (n_L-AmB = 4, 12.5% vs n_ABLC = 0, 0.0%; P = 0.042) and to have a lower creatinine clearance at the start of therapy (L-AmB = 79.6 mg/dl versus ABLC = 100.4 mg/dl; P = 0.008). Successful treatment was achieved in 27 (73.0%) of ABLC patients and 22 (68.8%) of L-AmB patients (P = 0.700). Amphotericin B was discontinued due to documented completion of therapy for 17 (45.9%) ABLC patients and 18 (56.3%) L-AmB patients (P = 0.553). Acute kidney injury (AKI) was the documented reason of treatment cessation for 10 (27.0%) ABLC and 1 (3.1%) L-AmB patient (P = 0.007). ABLC and L-AmB both appear to be equally efficacious in the treatment of severe coccidioidomycosis. L-AmB may have less renal toxicity than ABLC and may be the preferred agent in baseline renal impairment.

Fungi that Infect Humans

Fungi must meet four criteria to infect humans: growth at human body temperatures, circumvention or penetration of surface barriers, lysis and absorption of tissue, and resistance to immune defenses, including elevated body temperatures. Morphogenesis between small round, detachable cells and long, connected cells is the mechanism by which fungi solve problems of locomotion around or through host barriers. Secretion of lytic enzymes, and uptake systems for the released nutrients, are necessary if a fungus is to nutritionally utilize human tissue. Last, the potent human immune system evolved in the interaction with potential fungal pathogens, so few fungi meet all four conditions for a healthy human host. Paradoxically, the advances of modern medicine have made millions of people newly susceptible to fungal infections by disrupting immune defenses. This article explores how different members of four fungal phyla use different strategies to fulfill the four criteria to infect humans: the Entomophthorales, the Mucorales, the Ascomycota, and the Basidiomycota. Unique traits confer human pathogenic potential on various important members of these phyla: pathogenic Onygenales comprising thermal dimorphs such as Histoplasma and Coccidioides; the Cryptococcus spp. that infect immunocompromised as well as healthy humans; and important pathogens of immunocompromised patients-Candida, Pneumocystis, and Aspergillus spp. Also discussed are agents of neglected tropical diseases important in global health such as mycetoma and paracoccidiomycosis and common pathogens rarely implicated in serious illness such as dermatophytes. Commensalism is considered, as well as parasitism, in shaping genomes and physiological systems of hosts and fungi during evolution.

Remote sensing observation of annual dust cycles and possible causality of Kawasaki disease outbreaks in Japan

Kawasaki disease (KD) is a rare vascular disease that, if left untreated, can result in irreparable cardiac damage in children. While the symptoms of KD are well-known, as are best practices for treatment, the etiology of the disease and the factors contributing to KD outbreaks remain puzzling to both medical practitioners and scientists alike. Recently, a fungus known as Candida, originating in the farmlands of China, has been blamed for outbreaks in China and Japan, with the hypothesis that it can be transported over long ranges via different wind mechanisms. This paper provides evidence to understand the transport mechanisms of dust at different geographic locations and the cause of the annual spike of KD in Japan. Candida is carried along with many other dusts, particles or aerosols, of various sizes in major seasonal wind currents. The evidence is based upon particle categorization using the Moderate Resolution Imaging Spectrometer (MODIS) Aerosol Optical Depth (AOD), Fine Mode Fraction (FMF) and Ångström Exponent (AE), the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) attenuated backscatter and aerosol subtype, and the Aerosol Robotic Network's (AERONET) derived volume concentration. We found that seasonality associated with aerosol size distribution at different geographic locations plays a role in identifying dominant abundance at each location. Knowing the typical size of the Candida fungus, and analyzing aerosol characteristics using AERONET data reveals possible particle transport association with KD events at different locations. Thus, understanding transport mechanisms and accurate identification of aerosol sources is important in order to understand possible triggers to outbreaks of KD. This work provides future opportunities to leverage machine learning, including state-of-the-art deep architectures, to build predictive models of KD outbreaks, with the ultimate goal of early forecasting and intervention within a nascent global health early-warning system.

Coccidioidomycosis and the skin: a comprehensive review

Coccidioidomycosis is a highly prevalent disease in the Western hemisphere. It is considered one of the most virulent primary fungal infections. Coccidioides species live in arid and semi-arid regions, causing mainly pulmonary infection through inhalation of arthroconidia although many other organs can be affected. Primary inoculation is rare. Since the first case of coccidioidomycosis was reported in 1892, the skin has been identified as an important target of this disease. Knowledge of cutaneous clinical forms of this infection is important and very useful for establishing prompt diagnosis and treatment. The purpose of this article is to provide a review of this infection, emphasizing its cutaneous manifestations, diagnostic methods and current treatment.

Pediatric Coccidioidomycosis Patients: Perceptions, Quality of Life and Psychosocial Factors

Research investigating the effects of coccidioidomycosis (valley fever) on children and the psychosocial implications of this disease in general is lacking. This study reviews what is known about pediatric coccidioidomycosis patients. It documents the psychological functioning, quality of life, and illness perceptions of a sample of coccidioidomycosis patient families. Primary caregivers of pediatric patients and patients from a major hospital in the San Joaquin Valley of California were interviewed regarding their perceptions of disease detection, access to care and the patient/family experience.

Valley fever: danger lurking in a dust cloud

Coccidioides immitis and Coccidioides posadasii contribute to the development of Valley Fever. The ability of these fungal pathogens to evade the host immune system creates difficulty in recognition and treatment of this debilitating infection. In this review, we describe the current knowledge of Valley Fever and approaches to improve prevention, detection, and treatment.

The coccidioidomycosis conundrum: a rare parotid mass

A man, age 62 years, presented to the clinic with a 2-week history of increased nontender, nonerythematous, indurated right-sided parotid swelling. A 4 × 6-cm firm, well-circumscribed mass was palpated in the right parotid gland. A fine-needle aspiration biopsy was performed on the parotid mass with aspiration of 0.5 cc of purulent fluid with some blood. Cultures from the aspirate revealed Coccidioides immitis confirmed by DNA probe. Pathology slides revealed fungal spores. The patient was treated with 800 mg of fluconazole every day for 3 months with resolution of the parotid swelling. However, persistent cervical adenopathy remains.Although this is a rare case of acute parotid swelling, Coccidioides immitis should be considered in the differential diagnosis of parotid masses in a patient with previous coccidioidomycosis. There may be a potential for an increase in frequency and variety of atypical extrapulmonary manifestations of coccidioidomycosis that parallels the increase in coccidioidomycotic pulmonary infections. Long-term antifungal therapy appears essential for control.

Coccidioidomycosis: epidemiology

Coccidioidomycosis consists of a spectrum of disease, ranging from a mild, self-limited, febrile illness to severe, life-threatening infection. It is caused by the soil-dwelling fungi, Coccidioides immitis and C. posadasii, which are present in diverse endemic areas. Climate changes and environmental factors affect the Coccidioides lifecycle and influence infection rates. The incidence of coccidioidomycosis has risen substantially over the past two decades. The vast majority of Coccidioides infections occur in the endemic zones, such as California, Arizona, Mexico, and Central America. Infections occurring outside those zones appear to be increasingly common, and pose unique clinical and public health challenges. It has long been known that elderly persons, pregnant women, and members of certain ethnic groups are at risk for severe or disseminated coccidioidomycosis. In recent years, it has become evident that persons with immunodeficiency diseases, diabetics, transplant recipients, and prisoners are also particularly vulnerable.

The impact of early and brief corticosteroids on the clinical course of primary pulmonary coccidioidomycosis

OBJECTIVE

Primary pulmonary coccidioidomycosis can often be associated with hypersensitivity symptoms treatable with a short course of palliative corticosteroids. Long-term use of corticosteroids is a known risk factor for severe or disseminated infection but the effects of short-term use are not known.

METHODS

A retrospective review was conducted of immunocompetent patients with acute pulmonary coccidioidomycosis who received systemic corticosteroids for relief of coccidioidal-related symptoms. Age- and sex-matched controls were also reviewed. Predetermined end-points were assessed.

RESULTS

Seventy-four patients met inclusion criteria for the corticosteroid-treated group, and 74 controls were identified. Cumulative corticosteroid (prednisone-equivalent) doses were 10 mg → 3,600 mg (mean = 206 mg; median = 120 mg). Corticosteroids were prescribed most commonly for rash 43/74 [58%] or asthma/wheezing/cough 30/74 [41%]. Coccidioidal-related hospitalization occurred in 19 patients in the corticosteroid group vs. 22 in the control group (P = .58). Coccidioidal-related symptoms resolved within a mean of 19 weeks (median = 8 weeks [range = 2-208 weeks]) vs. 32.3 weeks (median = 8 weeks [range = 1-1040 weeks]) in the corticosteroid and control groups (P = .38). Relapse of symptoms occurred in 12% of both groups (P > .99). Extrapulmonary dissemination occurred in 3% vs. 4.0% (P > .99) in the corticosteroid and control groups, respectively.

CONCLUSION

This study found no adverse effects of short-term corticosteroid therapy for early symptomatic treatment in acute pulmonary coccidioidomycosis.

Molecular evolution of the deuterolysin (M35) family genes in Coccidioides

Coccidioides is a primary fungal pathogen of humans, causing life-threatening respiratory disease known as coccidioidomycosis (Valley fever) in immunocompromised individuals. Recently, Sharpton et al (2009) found that the deuterolysin (M35) family genes were significantly expanded in both the Coccidioides genus and in U. reesii, and that Coccidioides has acquired three more M35 family genes than U. reesii. In the present work, phylogenetic analyses based on a total of 28 M35 family genes using different alignments and tree-building methods consistently revealed five clades with high nodal supports. Interestingly, likelihood ratio tests suggested significant differences in selective pressure on the ancestral lineage of three additional duplicated M35 family genes from Coccidioides species compared to the other lineages in the phylogeny, which may be associated with novel functional adaptations of M35 family genes in the Coccidioides species, e.g., recent pathogenesis acquisition. Our study adds to the expanding view of M35 family gene evolution and functions as well as establishes a theoretical foundation for future experimental investigations.

The public health impact of coccidioidomycosis in Arizona and California

The numbers of reported cases of coccidioidomycosis in Arizona and California have risen dramatically over the past decade, with a 97.8% and 91.1% increase in incidence rates from 2001 to 2006 in the two states, respectively. Of those cases with reported race/ethnicity information, Black/African Americans in Arizona and Hispanics and African/Americans in California experienced a disproportionately higher frequency of disease compared to other racial/ethnic groups. Lack of early diagnosis continues to be a problem, particularly in suspect community-acquired pneumonia, underscoring the need for more rapid and sensitive tests. Similarly, the inability of currently available therapeutics to reduce the duration and morbidity of this disease underscores the need for improved therapeutics and a preventive vaccine.

Coccidioidomycosis in African Americans

Coccidioidomycosis is caused by Coccidioides species, a fungus endemic to the desert regions of the southwestern United States, and is of particular concern for African Americans. We performed a PubMed search of the English-language medical literature on coccidioidomycosis in African Americans and summarized the pertinent literature. Search terms were coccidioidomycosis, Coccidioides, race, ethnicity, African, black, and Negro. The proceedings of the national and international coccidioidomycosis symposia were searched. All relevant articles and their cited references were reviewed; those with epidemiological, immunologic, clinical, and therapeutic data pertaining to coccidioidomycosis in African Americans were included in the review. Numerous studies documented an increased predilection for severe coccidioidal infections, coccidioidomycosis-related hospitalizations, and extrapulmonary dissemination in persons of African descent; however, most of the published studies are variably problematic. The immunologic mechanism for this predilection is unclear. The clinical features and treatment recommendations are summarized. Medical practitioners need to be alert to the possibility of coccidioidomycosis in persons with recent travel to or residence in an area where the disease is endemic.

[Skin and mucous membrane manifestations of coccidioidomycosis: a study of thirty cases in the Brazilian states of Piauí and Maranhão]

BACKGROUND

Coccidioidomycosis is a systemic mycosis that usually presents as a benign infection. Patients generally recover spontaneously; however, a small proportion of infected individuals develop progressive complications that may affect the skin in the form of disseminated pleomorphic lesions and may become fatal.

OBJECTIVES

To identify and describe skin and mucous membrane manifestations of coccidioidomycosis, to identify occupational hazards associated with the disease and to determine its associated clinical presentation.

METHODS

A study conducted between 2003 and 2006 involving 30 patients from the Brazilian states of Piauí and Maranhão with coccidioidomycosis diagnosed by direct microscopy, sputum culture or screening serology using agar gel double immunodiffusion, in association with anamnesis and physical examination.

RESULTS

Extrapulmonary lesions were found in 13 cases (43.3%), consisting predominantly of dermatological manifestations of hypersensitivity: erythema nodosum (26.6%), exanthema with erythematosquamous lesions (26.6%) and erythema multiforme (23.3%), as well as ulcerations of the tongue (13.3%), lip ulcers (6.6%) and subcutaneous abscess (3.3%). These manifestations were seen during the acute phase of the disease.

CONCLUSIONS

Skin manifestations associated with an acute respiratory infection reinforce the hypothesis of a diagnosis of coccidioidomycosis, particularly in individuals who hunt armadillos or in those exposed to soil excavation.

PRIMARY PULMONARY COCCIDIOIDOMYCOSIS : EXPERIMENTAL INFECTION WITH COCCIDIOIDES IMMITIS

1. The literature concerning inhalation infection with Coccidioides immitis is briefly reviewed. 2. A laboratory technique for exposing animals to inhalation of the spores of Coccidioides immitis is described. 3. Primary pulmonary infection was produced in 42 per cent of 72 animals exposed by this method. 4. No marked weight loss was apparent in the animals infected. 5. Skin tests with coccidioidin were not entirely satisfactory in diagnosis. Positive skin tests with coccidioidin were obtained in many of the infected animals, but inconsistencies occurred. 6. The gross and microscopic lesions are briefly described and illustrated.

Genetic diversity among clinical Coccidioides spp. isolates in Arizona

Increasing coccidioidomycosis rates in Arizona may indicate the development of a hypervirulent strain. One hundred and twenty-one clinical Coccidioides spp. isolates were collected over 16 months from Maricopa, Graham, Yuma, and Pima counties in Arizona. The patient age distribution ranged from 9 to 91 years, with a median age of 58 years; 36% were female, and 64% male. All isolates were analyzed by measuring length polymorphisms in nine distinct microsatellite regions. The three microsatellites found to have the greatest discriminatory power for Coccidioides posadasii were: K03 (0.87), GA37 (0.83), and K01 (0.78). The majority of isolates (n=119) were C. posadasii. Duplicate isolates (n=28) from 13 patients showed single strain infections. Phylogenetic analysis of the microsatellite data showed no dominant microsatellite pattern. We conclude that the increase in reported cases of coccidioidomycosis in Arizona is not linked to a dominant, hypervirulent strain of Coccidioides posadasii.

The Early History of Coccidioidomycosis: 1892-1945

Coccidioidomycosis was first discovered by a medical student in Argentina in 1892, and knowledge about the infection mostly arose from observations of clinicians and scientists in California, primarily at Stanford University Medical Center. Some discoveries came by chance. Many others arose from careful epidemiologic and clinical investigations in the San Joaquin Valley during the 1930s, when people migrated there from the "Dust Bowl" of the Midwest, and during the 1940s, when the events of World War II brought military recruits, prisoners of war, and persons of Japanese descent to camps and other areas of endemicity. Especially impressive were the contributions of Charles E. Smith, who tirelessly studied this disease throughout his professional career.

Fungal diseases: an evolving public health challenge

The emergence of new fungal pathogens and the resurgence of mycotic diseases that had previously been uncommon is a serious and growing public health problem. This review examines the factors involved in the emergence or re-emergence of several mycotic diseases, including coccidioidomycosis and cryptococcosis, over the past two decades. New approaches to prevention and control are also discussed.

Coccidioidomycosis: changing perceptions and creating opportunities for its control

The perceptions of coccidioidomycosis as a medical problem has undergone sequential and dramatic metamorphoses since its first description more than a century ago. First thought to be rare and lethal, coccidioidomycosis was subsequently found to be common and often mild. During World War II, its overall impact upon large populations came sharply into focus and the consequences for public health became clearer. Early treatments had significant limitations and toxicities, and therefore treatment of coccidioidomycosis was reserved for only the sickest patients. Since then, safer oral therapies have become commonplace. Despite their availability, there has been no investigation of their use in the less severe and much more common early infections. Even newer drugs such as nikkomycin Z, which might actually cure infections, until very recently have had trouble finding a sponsor to move it through clinical trials. Perceptions once formed by the understanding of coccidioidomycosis as a medical problem now appear to hinder the future study of newer therapeutic opportunities. It is suggested in this review that it is time to revisit and possibly change these perceptions if we are to improve our care of patients.

Assessment of Climate Coccidioidomycosis Model: Model Sensitivity for Assessing Climatologic Effects on the Risk of Acquiring Coccidioidomycosis

Understanding the predictive relationships between climate variability and coccidioidomycosis is of great importance for the development of an effective public health decision-support system. Preliminary regression-based climate modeling studies have shown that about 80% of the variance in seasonal coccidioidomycosis incidence for southern Arizona can be explained by precipitation and dust-related climate scenarios prior to and concurrent with outbreaks. In earlier studies, precipitation during the normally arid foresummer 1.5-2 years prior to the season of exposure was found to be the dominant predictor. Here, the sensitivity of the seasonal modeling approach is examined as it relates to data quality control (QC), data trends, and exposure adjustment methodologies. Sensitivity analysis is based on both the original period of record, 1992-2003, and updated coccidioidomycosis incidence and climate data extending the period of record through 2005. Results indicate that models using case-level data exposure adjustment do not suffer significantly if individual case report data are used "as is." Results also show that the overall increasing trend in incidence is beyond explanation through climate variability alone. However, results also confirm that climate accounts for much of the coccidioidomycosis incidence variability about the trend from 1992 to 2005. These strongly significant relationships between climate conditions and coccidioidomycosis incidence obtained through regression modeling further support the dual "grow and blow" hypothesis for climate-related coccidioidomycosis incidence risk.

Coccidioidomycosis: a review and update

Coccidioidomycosis occurs in arid and semi-arid regions of the New World from the western United States to Argentina. Highly endemic areas are present in the southwest United States. Coccidioides species live in the soil and produce pulmonary infection via airborne arthroconidia. The skin may be involved by dissemination of the infection, or by reactive eruptions, such as a generalized exanthem or erythema nodosum. Interstitial granulomatous dermatitis and Sweet's syndrome have recently been recognized as additional reactive signs of the infection. Coccidioidomycosis is a "great imitator" with protean manifestations. Cutaneous findings may be helpful clues in the diagnosis of this increasingly important disease.

Coccidioidomycosis: host response and vaccine development

Coccidioidomycosis is caused by the dimorphic fungi in the genus Coccidioides. These fungi live as mycelia in the soil of desert areas of the American Southwest, and when the infectious spores, the arthroconidia, are inhaled, they convert into the parasitic spherule/endospore phase. Most infections are mild, but these organisms are frank pathogens and can cause severe lethal disease in fully immunocompetent individuals. While there is increased risk of disseminated disease in certain racial groups and immunocompromised persons, the fact that there are hosts who contain the initial infection and exhibit long-term immunity to reinfection supports the hypothesis that a vaccine against these pathogens is feasible. Multiple studies have shown that protective immunity against primary disease is associated with T-helper 1 (Th-1)-associated immune responses. The single best vaccine in animal models, formalin-killed spherules (FKS), was tested in a human trial but was not found to be significantly protective. This result has prompted studies to better define immunodominant Coccidioides antigen with the thought that a subunit vaccine would be protective. These efforts have defined multiple candidates, but the single best individual immunogen is the protein termed antigen 2/proline-rich antigen (Ag2/PRA). Studies in multiple laboratories have shown that Ag2/PRA as both protein and genetic vaccines provides significant protection against mice challenged systemically with Coccidioides. Unfortunately, compared to the FKS vaccine, it is significantly less protective as measured by both assays of reduction in fungal CFU and assays of survival. The capacity of Ag2/PRA to induce only partial protection was emphasized when animals were challenged intranasally. Thus, there is a need to define new candidates to create a multivalent vaccine to increase the effectiveness of Ag2/PRA. Efforts of genomic screening using expression library immunization or bioinformatic approaches to identify new candidates have revealed at least two new protective proteins, expression library immunization antigen 1 (ELI-Ag1) and a beta-1,3-glucanosyltransferase (GEL-1). In addition, previously discovered antigens such as Coccidioides-specific antigen (CSA) should be evaluated in assays of protection. While studies have yet to be completed with combinations of the current candidates, the hypothesis is that with increased numbers of candidates in a multivalent vaccine, there will be increased protection. As the genome sequences of the two Coccidioides strains which are under way are completed and annotated, the effort to find new candidates can increase to provide a complete genomic scan for immunodominant proteins. Thus, much progress has been made in the discovery of subunit vaccine candidates against Coccidioides and there are several candidates showing modest levels of protection, but for complete protection against pulmonary challenge we need to continue the search for additional candidates.

Coccidioidomycosis: a descriptive survey of a reemerging disease. Clinical characteristics and current controversies

Coccidioidomycosis is a fungal disease with protean manifestations endemic to the Lower Sonoran Life Zone, which includes the hot deserts of the southwestern United States and areas of Mexico. Two hundred and twenty-three patients were found to have coccidioidomycosis at our institution from 1994-2002, the largest reported cohort of coccidioidomycosis patients since the 1950s. Of these patients, 58% presented with isolated pulmonary disease, 14% had high (>1:16) complement fixation titers without clear evidence of dissemination, 22% had definite disseminated disease, and 5% had unclassified disease. Enzyme immunoassay was a reliable diagnostic tool in those with symptomatic disease, but had a low specificity in those who were asymptomatic. Complement fixation titers of > or =1:16 were associated with dissemination to bone or skin but were not helpful in evaluating central nervous system disease. Thirteen percent of patients with high complement fixation titers (>1:16) without clear evidence of dissemination on presentation and 7% of those with isolated pulmonary disease eventually progressed to disseminated disease; 30% of Filipino patients with pulmonary disease progressed to disseminated disease. Nonwhite race was a predictor for dissemination; African American patients more often developed disseminated bony disease while Filipinos were more likely to develop cutaneous or central nervous system disease. Relapse of disseminated coccidioidomycosis occurred in 24% of patients; the risk was highest (71%) among those with central nervous system disease. Azole therapy was generally inferior to amphotericin B in disseminated disease. Predictors of permanent disability included African American or Filipino race, central nervous system disease, and bony disease.

Recombinant urease and urease DNA of Coccidioides immitis elicit an immunoprotective response against coccidioidomycosis in mice

Coccidioides immitis antigens which stimulate a T helper cell 1 (Th1) pathway of host immune response are considered to be essential components of a vaccine against coccidioidomycosis. Recombinant urease (rURE) and recombinant heat shock protein 60 (rHSP60) of C. immitis were expressed in Escherichia coli and tested as vaccine candidates in BALB/c mice. A synthetic oligodeoxynucleotide which contained unmethylated CpG dinucleotides and was previously shown to enhance a murine Th1 response was used as an immunoadjuvant. T cells isolated from the spleens and lymph nodes of the rURE- and rHSP60-immune mice showed in vitro proliferative responses to the respective recombinant protein, but only those T lymphocytes from rURE-immunized mice revealed markedly elevated levels of expression of selected Th1-type cytokine genes. BALB/c mice immunized subcutaneously with rURE and subsequently challenged by the intraperitoneal (i.p.) route with a lethal inoculum of C. immitis arthroconidia demonstrated a significant reduction in the level of C. immitis infection compared to control animals. rHSP60 was much less effective as a protective antigen. Evaluation of cytokine gene expression in lung tissue and levels of recombinant urease-specific immunoglobulins (immunoglobulin G1 [IgG1] versus IgG2a) in murine sera at 12 days after challenge provided additional evidence that immunization with rURE stimulated a Th1 response to the pathogen. Urease was further evaluated by expression of the URE gene in a mammalian plasmid vector (pSecTag2A.URE) which was used to immunize mice by the intradermal route. In this case, 82% of the vector construct-immunized animals survived more than 40 days after i.p. infection, compared to only 10% of the mice immunized with the vector alone. In addition, 87% of the pSecTag2A.URE-immunized survivors had sterile lungs and spleens. These data support the need for further evaluation of the C. immitis urease as a candidate vaccine against coccidioidomycosis.

Risk factors for severe pulmonary and disseminated coccidioidomycosis: Kern County, California, 1995-1996

Surveillance for coccidioidomycosis (CM) and a case-control study for risk factors among adults were conducted in Kern County, California. From January 1995 through December 1996, 905 cases of CM were identified, for an annual incidence of 86 cases per 100,000 population. A total of 380 adults were enrolled in the case-control study: 77 had severe pulmonary disease, 33 had disseminated disease, and 270 control patients had mild disease. Independent risk factors for severe pulmonary disease included diabetes, recent history of cigarette smoking, income of < $15,000 per year, and older age. Oral antifungal therapy before hospitalization was associated with a reduced risk of CM pneumonia. Risk factors for disseminated disease were black race, income of < $15,000 per year, and pregnancy. Early treatment of CM with oral antifungal agents may prevent severe pulmonary disease in groups considered to be at high risk, such as elderly individuals, persons with diabetes, and smokers. Persons at risk for severe CM may benefit from vaccination once an effective CM vaccine is available.