Coccidioides Fungemia in Six Patients, with a Review of the Literature

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

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

Fungal Endocarditis: Pathophysiology, Epidemiology, Clinical Presentation, Diagnosis, and Management

Fungal endocarditis accounts for 1% to 3% of all infective endocarditis cases, is associated with high morbidity and mortality (>70%), and presents numerous challenges during clinical care. Candida spp. are the most common causes of fungal endocarditis, implicated in over 50% of cases, followed by Aspergillus and Histoplasma spp. Important risk factors for fungal endocarditis include prosthetic valves, prior heart surgery, and injection drug use. The signs and symptoms of fungal endocarditis are nonspecific, and a high degree of clinical suspicion coupled with the judicious use of diagnostic tests is required for diagnosis. In addition to microbiological diagnostics (e.g., blood culture for Candida spp. or galactomannan testing and PCR for Aspergillus spp.), echocardiography remains critical for evaluation of potential infective endocarditis, although radionuclide imaging modalities such as 18F-fluorodeoxyglucose positron emission tomography/computed tomography are increasingly being used. A multimodal treatment approach is necessary: surgery is usually required and should be accompanied by long-term systemic antifungal therapy, such as echinocandin therapy for Candida endocarditis or voriconazole therapy for Aspergillus endocarditis.

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

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

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%).

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.

Endemic fungal infections in solid organ transplant recipients-Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

These updated guidelines from the Infectious Diseases Community of Practice of the American Society of Transplantation review the diagnosis, prevention and management of blastomycosis, histoplasmosis, and coccidioidomycosis in the pre- and post-transplant period. Though each of these endemic fungal infections has unique epidemiology and clinical manifestations, they all share a predilection for primary pulmonary infection and may cause disseminated infection, particularly in immunocompromised hosts. Culture remains the gold standard for definitive diagnosis, but more rapid diagnosis may be achieved with direct visualization of organisms from clinical specimens and antigen-based enzyme immunoassay assays. Serology is of limited utility in transplant recipients. The mainstay of treatment for severe infections remains liposomal amphotericin followed by a step-down azole therapy. Cases of mild to moderate severity with no CNS involvement may be treated with azole therapy alone. The newer generation azoles provide additional treatment options, but supported currently with limited clinical efficacy data. Azole therapy in transplant recipients presents a unique challenge owing to the drug-drug interactions with immunosuppressant agents. Therapeutic drug monitoring of azole levels is an essential component of effective and safe therapy. Infection prevention centers around minimizing epidemiological exposures, early clinical recognition, and azole prophylaxis in selected individuals.

Coccidioidomycosis in Patients with Selected Solid Organ Cancers: A Case Series and Review of Medical Literature

Coccidioidomycosis is a common infection in the desert southwestern USA; approximately 3 % of healthy persons in Arizona alone become infected annually. Coccidioidomycosis may be severe in immunocompromised persons, but experience among patients with solid organ cancer has not been fully described. Therefore, we aimed to describe the clinical courses of patients whose cancers were complicated by coccidioidomycosis at our institution, which is located in an area with endemic Coccidioides. To do so, we conducted a retrospective review from January 1, 2000, through December 31, 2014, of all patients with breast, colorectal, or ovarian cancer whose cancer courses were complicated by coccidioidomycosis. We identified 17,576 cancer patients; 14 (0.08 %) of these patients met criteria for proven or probable coccidioidomycosis diagnosed within the first 2 years after the cancer diagnosis. All of these patients had primary pulmonary coccidioidomycosis, none had relapsed prior infection, and 1 had possible extrapulmonary dissemination. Five had active coccidioidal infection during chemotherapy, 1 of whom was hospitalized for coccidioidal pneumonia. All were treated with fluconazole, and all improved clinically. Eleven did not require prolonged courses of fluconazole. There were no clearly demonstrated episodes of relapsed infection. In conclusion, coccidioidomycosis was not a common complication of breast, colorectal, or ovarian cancers in patients treated at our institution, and it was not commonly complicated by severe or disseminated infection.

Donor-Derived Coccidioides immitis Endocarditis and Disseminated Infection in the Setting of Solid Organ Transplantation

Background.  Endocarditis is a rare manifestation of infection with Coccidioides. This is the first reported case of donor-derived Coccidioides endocarditis obtained from a heart transplant. Methods.  We present a unique case of donor-derived Coccidioides immitis endocarditis and disseminated infection in a heart transplant patient. We also conducted a review of the literature to identify other cases of donor-derived coccidioidomycosis in solid organ transplant recipients and reviewed their clinical characteristics. Results.  Fifteen prior cases of donor-derived coccidioidomycosis were identified. A majority of these cases were diagnosed by positive culture (83%). Mortality was high at 58%. Conclusions.  Clinicians should maintain a high index of suspicion for disseminated coccidioidomycosis in patients who received transplants with organs from donors with a history of residing in endemic regions.

Endocarditis due to Coccidioides spp: The Seventh Case

Coccidioides, a dimorphic fungus endemic within the Americas, primarily causes pulmonary disease but may disseminate. We describe a case of confirmed Coccidioides endocarditis, the seventh reported in literature. Coccidioides endocarditis often requires tissue diagnosis and combined surgical and medical treatment.

Beyond the superficial: Coccidioides immitis fungaemia in a man with fever, fatigue and skin nodules: a case of an emerging and evolving pathogen

Coccidioidomycosis is an insidious fungal disease, endemic to arid regions of the Americas, which is becoming more frequently recognised worldwide. While most infections resemble a mild respiratory illness, a subset of cases progress to severe pneumonia or systemic dissemination. Here, we describe a case of disseminated coccidioidomycosis in a 54-year-old immunocompetent African-American man with geographic and demographic risk factors for Coccidiodes acquisition who presented with 2 months of fevers, fatigue, weight loss and painful skin lesions. Blood count and serum chemistry studies initially demonstrated leukocytosis, anaemia, hyponatraemia and acute renal failure. Chest imaging revealed numerous small pulmonary nodules and skin biopsy, serological studies and blood cultures eventually confirmed disseminated infection with Coccidioides immitis. This case highlights important features regarding the risk factors, spectrum of clinical findings, evaluation and treatment of coccidioidomycosis relevant to providers in endemic areas and throughout the world.

Recent advances in our understanding of the environmental, epidemiological, immunological, and clinical dimensions of coccidioidomycosis

Coccidioidomycosis is the endemic mycosis caused by the fungal pathogens Coccidioides immitis and C. posadasii. This review is a summary of the recent advances that have been made in the understanding of this pathogen, including its mycology, genetics, and niche in the environment. Updates on the epidemiology of the organism emphasize that it is a continuing, significant problem in areas of endemicity. For a variety of reasons, the number of reported coccidioidal infections has increased dramatically over the past decade. While continual improvements in the fields of organ transplantation and management of autoimmune disorders and patients with HIV have led to dilemmas with concurrent infection with coccidioidomycosis, they have also led to advances in the understanding of the human immune response to infection. There have been some advances in therapeutics with the increased use of newer azoles. Lastly, there is an overview of the ongoing search for a preventative vaccine.

Donor-derived Coccidioides immitis fungemia in solid organ transplant recipients

We report disseminated coccidioidomycosis in 3 transplant recipients from a donor in an endemic area found to have unrecognized meningeal coccidioidomycosis. All 3 transplant recipients presented within 3 weeks of receipt of their organ. Only 1 organ recipient survived the acute presentation of coccidioidomycosis. Serologic testing for Coccidioides immitis infection should be considered for organ donors residing in endemic areas.

Next-generation sequencing of Coccidioides immitis isolated during cluster investigation

Next-generation sequencing enables use of whole-genome sequence typing (WGST) as a viable and discriminatory tool for genotyping and molecular epidemiologic analysis. We used WGST to confirm the linkage of a cluster of Coccidioides immitis isolates from 3 patients who received organ transplants from a single donor who later had positive test results for coccidioidomycosis. Isolates from the 3 patients were nearly genetically identical (a total of 3 single-nucleotide polymorphisms identified among them), thereby demonstrating direct descent of the 3 isolates from an original isolate. We used WGST to demonstrate the genotypic relatedness of C. immitis isolates that were also epidemiologically linked. Thus, WGST offers unique benefits to public health for investigation of clusters considered to be linked to a single source.