Coccidioidomycosis: Epidemiology, Fungal Pathogenesis, and Therapeutic Development

Miliary coccidioidomycosis mimicking tuberculosis: Case report and review of literature

Miliary coccidioidomycosis is a severe manifestation of diseases caused by Coccidioides immitis and Coccidioides posadasii that is endemic to the southwestern United States as well as Central and South America. While most cases of coccidioidomycosis present with pulmonary disease, certain risk factors increase the risk for disseminated disease. We present a case of miliary coccidioidomycosis in a 46-year-old patient with uncontrolled diabetes. Additionally, we review the features of thirty-seven cases of patients with miliary coccidioidomycosis.

Developing a Coccidioides posadasii and SARS-CoV-2 Co-infection Model in the K18-hACE2 Transgenic Mouse

BACKGROUND

Early reports showed that patients with COVID-19 had recrudescence of previously resolved coccidioidomycosis (Valley fever, VF), and there were indications that coinfection had more severe outcomes. We therefore investigated serial infection of Coccidioides posadasii and SARS-CoV-2 in a K18-hACE2 mouse model to assess disease outcomes.

METHODS

In our model, we challenged K18-hACE2 mice sequentially with a sub-lethal dose of SARS-CoV-2 and 24 hours later with low virulence strain of Coccidioides posadasii, and vice versa, compared to mice that only received a single infection challenge. We performed survival and pathogenesis mouse studies as well as looked at the systemic immune response differences between treatment groups.

RESULTS

Here we show that co-infected groups have a more severe disease progression as well as a decrease in survival. Importantly, results differ depending on the SARS-CoV-2 variant (WA-1, Delta, or Omicron) and infection timing (SARS-CoV-2 first, C. posadasii second or vice versa). We find that groups that are infected with the virus first had a decrease in survival, increased morbidity and weight loss, increased fungal and viral burdens, differences in immune responses, and the amount and size of fungal spherules. We also find that groups coinfected with C. posadasii first have a decrease fungal burden and inflammatory responses.

CONCLUSIONS

This is the first in vivo model investigation of a coinfection of SARS-CoV-2 and Coccidioides. Because of the potential for increased severity of disease in a coinfection, we suggest populations that live in areas of high coccidioidomycosis endemicity may experience higher incidence of complicated disease progression with COVID-19.

Coccidioidomycosis and Histoplasmosis in Immunocompetent Individuals: A Comprehensive Review of Clinical Features, Diagnosis, and Management

Coccidioidomycosis and histoplasmosis are endemic mycoses caused by the Coccidioides species and Histoplasma capsulatum, respectively. While these fungal infections are often associated with immunocompromised individuals, they pose significant risks to immunocompetent hosts. This review comprehensively analyzes these infections in immunocompetent individuals, focusing on clinical features, diagnostic approaches, and management strategies. The current understanding of coccidioidomycosis and histoplasmosis in immunocompetent individuals includes their clinical presentations, diagnostic methodologies, and treatment options. A literature review encompassed recent studies, clinical guidelines, and expert opinions. Data were analyzed to highlight critical aspects of the clinical manifestations, diagnostic processes, and management of these infections in immunocompetent patients. Coccidioidomycosis typically presents with pulmonary symptoms that may range from mild to severe and can include chronic and disseminated forms. Histoplasmosis also presents a spectrum of pulmonary symptoms with the potential for extrapulmonary dissemination. Diagnostic approaches for both infections involve clinical evaluation, serological tests, culture, and imaging studies. Management strategies include antifungal therapies such as fluconazole and itraconazole for coccidioidomycosis and itraconazole and amphotericin B for histoplasmosis, with treatment duration and monitoring tailored to the severity of the infection. Coccidioidomycosis and histoplasmosis can significantly affect immunocompetent individuals, with clinical presentations varying widely from mild to severe. Accurate diagnosis and appropriate management are crucial for optimal outcomes. This review underscores the importance of awareness and timely intervention in managing these endemic mycoses and highlights the need for continued research into better diagnostic and therapeutic approaches.

Diagnosis, Treatment, and Outcome of Coccidioidal Osseous Infections: A Systematic Review

Extrapulmonary infections by Coccidioides spp., though rare, can occur via dissemination, affecting singular or multiple sites, including the skin and musculoskeletal system. Skeletal involvement often manifests as osteomyelitis, particularly in the axial skeleton. The present systematic review evaluates all documented cases of skeletal coccidioidomycosis to assess the diagnostic and treatment strategies alongside the outcomes, drawing insights from an analysis of 163 verified cases. A systematic review following PRISMA guidelines identified all studies reporting skeletal infections by Coccidioides spp. up to 2023 from the PubMed and Scopus databases. Eligible studies evaluated osteoarticular infections from Coccidioides spp. Data extraction included demographics, microbiological data, diagnostic methods, and treatment outcomes. Of the 501 initially identified records, a total of 163 patients from 69 studies met the inclusion criteria. Most cases were from the USA, predominantly males, while the median age of the population was 36 years. Diabetes mellitus was the common comorbidity (14.7%). C. immitis was the most prevalent pathogen. The spine and hand were common sites of infection (17.5% and 15.1%, respectively). Osteomyelitis by Coccidioides spp. was diagnosed, in most cases, by positive cultures (n = 68; 41.7%), while, in 49 (30.9%), both the histological examination and cultures yielded the fungus. Surgical debridement was performed in 80.9% of cases. A total of 118 (72.3%) patients were treated with monotherapy, while combination therapy with two or more antifungal agents was reported in 45 (17.7%). Amphotericin B (either liposomal or deoxycholate) was the most commonly given agent as monotherapy in 51 (31.2%) patients, while 30 (18.4%) patients received itraconazole as monotherapy. The rate of infection's resolution was higher in patients undergoing surgical debridement (79.5%), compared to those treated only with antifungal agents (51.6%, p = 0.003). Treatment outcomes showed complete resolution in 74.2% of patients, with a mortality rate of 9.2%. Coccidioidal osseous infections present diagnostic and therapeutic challenges. Surgical intervention is often necessary, complementing antifungal therapy. Vigilance for Coccidioides spp. infections, especially in regions with endemicity, is crucial, particularly when bacterial cultures yield negative results.

Coccidioides spp. exposure among military working dogs in endemic regions of the United States

Coccidioidomycosis is a fungal disease in arid regions of the United States that is predicted to expand with climate change. Cases in military personnel and military working dogs (MWDs) impact personnel readiness and result in healthcare costs. To examine Coccidioides exposure among MWDs, 276 banked serum samples were retrieved from dogs housed in California, Texas, Arizona, New Mexico, Nevada, and Utah. Using gel immunodiffusion, six (2.1%) specimens were IgG-positive and three (1.1%) were equivocally IgM-positive. The IgG-positive samples were from Arizona (2 [prevalence 8.0%]) and California (4 [3.7%]). These data will guide future efforts to study MWDs as sentinels for human coccidioidomycosis.

Cutaneous Coccidioidomycosis and Basal Cell Carcinoma: Case Report on a Diagnostic Dilemma

In the world of medical diagnoses, a particularly intriguing scenario unfolds, wherein the cutaneous manifestation of a systemic fungal infection disguises itself as a Basal Cell Carcinoma (BCC), a skin cancer. Coccidioidomycosis is an endemic fungal infection caused by inhaling spores of the fungus Coccidioides immitis. It is primarily a pneumonic illness which, in a few cases, has the potential to cause severe systemic disease. In this article, we report a case of a 60-year-old female with a known history of infiltrating ductal carcinoma of left breast status post lumpectomy and adjunct chemotherapy presented with complaints of cough, fever, and easy fatigability that seemed to be attributable to her immunocompromised state. She also had a pseudo-vesicular plaque on her left upper arm for two years. As we delve into the case, it becomes clear that Coccidioidomycosis and other opportunistic infections are commonplace among immunocompromised patients. Prior awareness of this condition and a cautious yet open-minded approach prevented gross misdiagnosis in our case. Physicians should be vigilant in diagnosing Coccidioidomycosis, especially in immunocompromised patients presenting with mild constitutional symptoms in endemic regions. Early detection and management are crucial to prevent severe complications and increase patient survival rates.

Spinal Infections Caused by Coccidioides Species

Introduction: Spinal Coccidioidomycosis, although rare, represents the most frequent osseous presentation of Coccidioides spp infection. The present review aims to describe the anatomical distribution, the epidemiological characteristics, and the diagnostic and therapeutic approach of this severe infection. Methods:A meticulous review of all published spinal Coccidioidomycosis cases was carried out. The studied population's demographics and the anatomical distribution of the infection were recorded. Furthermore, the medical and operative management as well as the disease outcome were studied. Results:Seventy-six cases (of which 78.9% males) with a mean age of 35.5 years were located. Regarding the anatomical distribution of the infection, the thoracic area was the most commonly affected spine region (26.3%). Among the studied patients, 14 (18.4%) were immunocompromised. Pain was the most commonly reported symptom (21.1%). Regarding the diagnostic approach of this infection, plain x-ray or CT scan indicated the disease in the majority of cases (44.7%). Pathology (48.7%), serology (42.1%) and microbiological examinations (35.5%) further established the firm diagnosis, with Coccidioides immitis being the most frequently isolated fungus. Medical management included mainly amphotericin B (in 57.9% of cases), followed by fluconazole (in 38.2% of cases). The disease required surgical intervention in the majority of cases (76.3%), while the infection had a successful outcome in 80.3% of cases. Conclusion:Spinal Coccidioidomycosis seems to require prolonged medical treatment, including proper antifungal therapy and, in most cases, operative management. Multidisciplinary approach, including infectious disease specialists, orthopaedic and/or spine surgeons, microbiologists and radiologists seems to be of utmost important for yielding favorable outcomes.

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.

Outcomes with severe pulmonary coccidioidomycosis and respiratory failure in the United States

Background:

Coccidioidomycosis is a fungal infection with presentations ranging from asymptomatic illness to severe pneumonia and respiratory failure. The outcomes of patients with severe pulmonary coccidioidomycosis requiring mechanical ventilation (MV) are not well understood.

Methods:

We performed a retrospective cohort analysis utilizing the Nationwide Inpatient Sample (NIS) from 2006 to 2017. Patients >18 years of age with a diagnosis of pulmonary coccidioidomycosis were included in the cohort.

Results:

A total of 11,045 patients were hospitalized with a diagnosis of pulmonary coccidioidomycosis during the study period. Of these, 826 (7.5%) patients required MV during their hospitalization with a mortality rate of 33.5% compared to 1.3% ( p < 0.01) for patients not requiring MV. Results of the multivariable logistic regression model show that risk factors for MV included the history of neurological disorders and paralysis (OR 3.38, 95% CI 2.70 to 4.20, p < 0.01; OR 3.13, 95% CI 1.91 to 5.15, p < 0.01, respectively) and HIV (OR 1.63, 95% 1.10 to 2.43, p < 0.01). Risk factors for mortality among patients requiring MV included older age (OR 1.24 per 10-year increase, 95% CI 1.08 to 1.42, p < 0.01), coagulopathy (OR 1.61, 95% CI 1.09 to 2.38, p = 0.01) and HIV (OR 2.83; 95% CI 1.32 to 6.10; p < 0.01).

Conclusions:

Approximately 7.5% of patients admitted with coccidioidomycosis in the United States require MV, and MV is associated with high mortality (33.5%).

Genomic Data Mining Reveals Abundant Uncharacterized Transporters in Coccidioides immitis and Coccidioides posadasii

Coccidioides immitis and Coccidioides posadasii are causative agents of coccidioidomycosis, commonly known as Valley Fever. The increasing Valley Fever cases in the past decades, the expansion of endemic regions, and the rising azole drug-resistant strains have underscored an urgent need for a better understanding of Coccidioides biology and new antifungal strategies. Transporters play essential roles in pathogen survival, growth, infection, and adaptation, and are considered as potential drug targets. However, the composition and roles of transport machinery in Coccidioides remain largely unknown. In this study, genomic data mining revealed an abundant, uncharacterized repertoire of transporters in Coccidioides genomes. The catalog included 1288 and 1235 transporter homologs in C. immitis and C. posadasii, respectively. They were further annotated to class, subclass, family, subfamily and range of substrates based on the Transport Classification (TC) system. They may play diverse roles in nutrient uptake, metabolite secretion, ion homeostasis, drug efflux, or signaling. This study represents an initial effort for a systems-level characterization of the transport machinery in these understudied fungal pathogens.

Important Mycosis of Wildlife: Emphasis on Etiology, Epidemiology, Diagnosis, and Pathology—A Review: PART 2

Wild animals are an important component of the ecosystem, and play a major role in it. However, in recent years, there has been an astronomical increase in the incidence of wildlife mycotic diseases leading to wildlife extermination. It is important to note that most of these mycotic diseases are zoonotic, and since there is a lot of attention given to zoonosis of a bacterial or viral origin in recent times, it is important to look into the mycotic diseases which may have zoonotic potential. Previously, the authors expatiated on some major wildlife mycotic diseases. In this review, we shed light on the etiology, epidemiology, diagnosis, pathogenesis, pathogenicity, macroscopic and microscopic pathology, and hematological and serum biochemical findings of dermatophytosis, coccidioidomycosis, blastomycosis, and sporotrichosis, which are very important mycoses of wildlife.

Coccidioidomycosis in 26 horses in California, USA: case series and review of the literature

Coccidioidomycosis is a fungal disease caused by Coccidioides immitis or Coccidioides posadasii. We searched the records of the California Animal Health and Food Safety Laboratory from 1990 through 2020 for cases of coccidioidomycosis in horses. The selection criteria for these cases were: 1) live-born horses submitted for autopsy, and 2) a diagnosis of coccidioidomycosis was established, regardless of cause of death. During that time, 19,054 horses were received, and 26 cases (0.14%) of coccidioidomycosis were diagnosed in horses, of which 19 (73%) cases had pneumonia and/or pleuritis with or without lesions in other organs, and 7 (27%) cases had lesions only in organs other than the lungs (nasal mucosa, spleen, thoracic lymph nodes, heart, pericardial sac, liver, kidney, mediastinum, and/or mesentery). Pneumonia was diagnosed as the cause of death in 1,838 (9.64%) of the horses received; Coccidioides spp. was the cause of pneumonia in 19 (1.0%) of these animals. Horses have been reported to have low susceptibility to coccidioidomycosis, and the severity and chronicity of the disease can be variable. Lesions in our cases consisted of multifocal-to-coalescing pyogranulomas with intralesional fungal spherules. Coccidioidomycosis must be considered a differential diagnosis in cases of persistent cough, chronic weight loss, fever, and cases with a travel history to, or living in, a region considered endemic for coccidioidomycosis. Coccidioides spp. infection should also be considered when pyogranulomatous inflammation is found within lung, spleen, nasal mucosa, and lymph nodes of horses.

Current Landscape of Coccidioidomycosis

Coccidioidomycosis, also known as Valley fever, is an endemic fungal infection commonly found in the southwestern parts of the United States. However, the disease has seen an increase in both in its area of residency and its prevalence. This review compiles some of the latest information on the epidemiology, current and in-development pharmaceutical approaches to treat the disease, trends and projections, diagnostic concerns, and the overlapping dynamics of coccidioidomycosis and COVID-19, including in special populations. This review provides an overview of the current diagnostic and therapeutic strategies and identifies areas of future development.

Coccidioidomycosis Cases at a Regional Referral Center, West Texas, USA, 2013–2019

We describe 73 patients with coccidioidomycosis diagnosed or treated at a regional referral center in West Texas, USA. Patients most at risk worked in oil production or agriculture; the most-associated health factors were smoking and diabetes. Patient demographics suggest that access to care may affect coccidioidomycosis diagnosis in this region.

Skeletal Infections Caused by Coccidioides Species

Background: Coccidioidomycosis represents an endemic and challenging disease, with rare extrapulmonary manifestations. The present review of all published cases of core and extremities osseous coccidioidomycosis aims to describe epidemiology, patients’ characteristics, symptoms as well as medical and surgical treatment options and their effectiveness. Methods: A thorough review of all published skeletal core and extremity infections due to Coccidioides species was conducted. Information regarding demographics, causative fungus, antifungal treatment (AFT), surgical management as well as the infection outcome was recorded. Results: A total of 92 cases of Coccidioides spp. skeletal infections were recorded in 87 patients. The patients’ mean age was 35.3 years. The most common site of infection was the spine (82.6%), followed by the foot (6.5%), while the predominant symptom upon presentation was pain (29.9%). Immunosuppressive conditions and/or medications were observed in 21 patients (24.1%). Regarding imaging methods, indicating diagnosis, plain X-rays or CT scans were performed in most patients (50.6%), followed by magnetic resonance imaging (MRI) (47.1%). Most cases were diagnosed through histopathology (62; 71.3%), followed by serology testing (36; 42.4%) and by cultures (35; 40.2%). In 32 cases (36.8%), Coccidioides immitis was cultured, while in the remaining 55 cases (63.2%) the fungus was not further characterized. Regarding AFT, amphotericin B was the preferred agent (52.9%), followed by fluconazole (43.3%). In most cases (78.2%) surgical treatment was also performed. Treatment was successful in 80.5% of cases. Conclusions: Skeletal core and extremity infections due to Coccidioides spp. represent a severe disease. With the available data, the combination of prolonged proper AFT with surgical intervention seems to be the optimal current therapeutic approach.

The clinical laboratory evolution in coccidioidomycosis detection: Future perspectives

Coccidioidomycosis is a systemic disease caused by the fungi Coccidioides immitis and C. posadasii. It is a prevalent disease in arid regions with high temperatures and low precipitations in America. Coccidioidomycosis is a highly endemic disease of US-Mexico border states but commonly underdiagnosed. The diagnosis of coccidiomycosis is not easy due to the lack of specific symptoms; it is usually an integral approach, including clinical laboratory tests as an essential part of the diagnosis. Nevertheless, despite various laboratory tests available, affordability can be a limitation, mainly in developing countries. This review's objectives are 1) to learn the different laboratory approaches that arose and their application for clinical diagnosis; 2) to discuss their advantages and weaknesses, and finally, 3) propose what is on the horizon for future advances in clinical laboratory diagnosis of coccidioidomycosis. It has been a long way in laboratory tests evolution to detect coccidioidomycosis from tissue microscopy to Real-Time PCR. However, there is a delay in technology adoption for Coccidioides spp. detection in the clinical laboratory. The molecular Point of Care Testing (POCT) technology has reached us in our trench while research in PCR variants stills on-going. None of the currently existing scientific literature in coccidioidomycosis research has mentioned it. However, this trend in infectious and non-infectious disease diagnosis will continue in that way in order to offer better options for an easy and fast diagnosis. Undoubtedly, the implementation of molecular POCT for Coccidioides spp. would save resources in health care attention and improve access to diagnostic tools.