Disseminated coccidioidomycosis

Evaluation of Host Constitutive and Ex Vivo Coccidioidal Antigen-Stimulated Immune Response in Dogs with Naturally Acquired Coccidioidomycosis

The early innate immune response to coccidioidomycosis has proven to be pivotal in directing the adaptive immune response and disease outcome in mice and humans but is unexplored in dogs. The objectives of this study were to evaluate the innate immune profile of dogs with coccidioidomycosis and determine if differences exist based on the extent of infection (i.e., pulmonary or disseminated). A total of 28 dogs with coccidioidomycosis (pulmonary, n = 16; disseminated, n = 12) and 10 seronegative healthy controls were enrolled. Immunologic testing was performed immediately, without ex vivo incubation (i.e., constitutive), and after coccidioidal antigen stimulation of whole blood cultures. Whole blood cultures were incubated with a phosphate-buffered solution (PBS) (negative control) or a coccidioidal antigen (rCTS1 (105-310); 10 µg/mL) for 24 h. A validated canine-specific multiplex bead-based assay was used to measure 12 cytokines in plasma and cell culture supernatant. Serum C-reactive protein (CRP) was measured with an ELISA assay. Leukocyte expression of toll-like receptors (TLRs)2 and TLR4 was measured using flow cytometry. Dogs with coccidioidomycosis had higher constitutive plasma keratinocyte chemotactic (KC)-like concentrations (p = 0.02) and serum CRP concentrations compared to controls (p < 0.001). Moreover, dogs with pulmonary coccidioidomycosis had higher serum CRP concentrations than those with dissemination (p = 0.001). Peripheral blood leukocytes from dogs with coccidioidomycosis produced higher concentrations of tumor necrosis factor (TNF)-α (p = 0.0003), interleukin (IL)-6 (p = 0.04), interferon (IFN)-γ (p = 0.03), monocyte chemoattractant protein (MCP)-1 (p = 0.02), IL-10 (p = 0.02), and lower IL-8 (p = 0.003) in supernatants following coccidioidal antigen stimulation when compared to those from control dogs. There was no detectable difference between dogs with pulmonary and disseminated disease. No differences in constitutive or stimulated leukocyte TLR2 and TLR4 expression were found. These results provide information about the constitutive and coccidioidal antigen-specific stimulated immune profile in dogs with naturally acquired coccidioidomycosis.

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.

(Ig)Easy diagnosis of disseminated coccidioidomycosis

An immunocompetent man in his 20s came to the hospital for shortness of breath, fevers and lower back pain with unintentional 20 lbs. weight loss. Relevant history included a recent trip to Arizona 3 months prior to presentation. On arrival, he was noted to have decreased breath sounds bilaterally, and paraspinal tenderness in the lumbar area. CT scan revealed diffuse pneumonitis and an abscess with osteomyelitis in the sacrum and right iliac bone. Continued respiratory decompensation led him to the intensive care unit where he had a bronchoscopy and later sacroiliac joint fluid collection was performed. Based on his travel history, and elevated serum IgE, liposomal amphotericin B was initiated. Later his antibodies against Coccidiodes resulted elevated and fungal cultures from the bronchoalveolar lavage and abscess from the sacral vertebrae grew mould, morphologically consistent with Coccidiodes posadasii He was transitioned to oral fluconazole and will have a close follow-up outpatient.

Travel-related risk factors for coccidioidomycosis

BACKGROUND

Coccidioidomycosis is a regionally endemic systemic mycosis with unique risk factors. Since people travel for business or pleasure, and often in conjunction with their avocations or hobbies, the objectives of this review were to describe these and other risk factors for coccidioidomycosis; to alert travel medicine clinicians to the different presenting manifestations of coccidioidomycosis; and to recommend effective treatment, disease control and prevention strategies.

METHODS

To meet the objectives of this review, Internet search engines were queried with the keywords as medical subject headings over the study period, 1970-2017.

RESULTS

The principle transmission mechanism of coccidioidomycosis is by deep inhalation of aerosolized arthroconidia with resulting symptomatic pulmonary infections ranging from febrile influenza-like illnesses to fatal disseminated mycoses. In addition to residency or travel in endemic areas, persons immunocompromised by advancing age, pregnancy, cancer, corticosteroid therapy, diabetes, organ transplantation and human immunodeficiency virus infection are at significantly increased risks of contracting coccidioidomycosis. Persons of African, Asian, Filipino and Hispanic descent are also at increased risks of contracting coccidioidomycosis. Hobbies associated with coccidioidomycosis have included armadillo hunting, model airplane flying and archaeological digging. Occupational risk factors for coccidioidomycosis include endemic exposures during military maneuvers, outdoor track and field events, road construction, solar-power and wind-power farm construction, archaeological excavation and prison work.

CONCLUSIONS

Coccidioidomycosis is more common in endemic and non-endemic areas than previously recognized and can result in considerable morbidity and mortality. Coccidioidomycosis is increasingly imported from endemic areas in the Western Hemisphere to non-endemic areas worldwide. Increased awareness of disease risk factors among the public and the international healthcare community will improve the timely diagnosis and treatment of coccidioidomycosis and prevent disease progression, dissemination and deaths in residents in and in travellers returning from endemic regions. A vaccine for the primary prevention of coccidioidomycosis would be cost-effective.

Antifungal therapeutics for dimorphic fungal pathogens

Dimorphic fungi cause several endemic mycoses which range from subclinical respiratory infections to life-threatening systemic disease. Pathogenic-phase cells of Histoplasma, Blastomyces, Paracoccidioides and Coccidioides escape elimination by the innate immune response with control ultimately requiring activation of cell-mediated immunity. Clinical management of disease relies primarily on antifungal compounds; however, dimorphic fungal pathogens create a number of challenges for antifungal drug therapy. In addition to the drug toxicity issues known for current antifungals, barriers to efficient drug treatment of dimorphic fungal infections include natural resistance to the echinocandins, residence of fungal cells within immune cells, the requirement for systemic delivery of drugs, prolonged treatment times, potential for latent infections, and lack of optimized standardized methodology for in vitro testing of drug susceptibilities. This review will highlight recent advances, current therapeutic options, and new compounds on the horizon for treating infections by dimorphic fungal pathogens.

Patient outcomes and surgical complications in coccidioidomycosis-related hydrocephalus: an institutional review

Object

Coccidioidomycosis is a common fungal infection in the southwestern US. Hydrocephalus is a serious complication of cranial coccidioidomycosis, and the surgical management of coccidioidomycosis-related hydrocephalus has unique challenges. The authors reviewed their institutional experience with hydrocephalus in the setting of coccidioidomycosis.

Methods

The authors retrospectively identified 44 patients diagnosed with coccidioidomycosis-related hydrocephalus at their institution since 1990, who underwent a total of 99 shunting procedures. The authors examined patient demographics, type of shunt and valve used, pressure settings, failure rates, medical treatment, ventricular response to shunting, and other variables.

Results

The majority of patients were young (average age 37 years) men (male/female ratio 28:16) with a mean follow-up of 63 months. Patients of Asian and African descent were overrepresented in the cohort compared with regional demographic data. The overall shunt failure rate during follow-up was 50%, and the average number of revisions required if the shunt failed was 2.5 (range 1–8). Low to moderate draining pressures (mean 88 mm H2O) were used in this cohort. Fourteen patients received intrathecal antifungals, and a trend of initiating intrathecal therapy after need for a shunt revision was observed (p = 0.051). The majority of shunt failures (81%) were due to mechanical blockages in the drainage system. Most patients (59%) had at least partial persistent postoperative ventriculomegaly despite successful CSF diversion. Four patients (9%) died due to coccidioidomycosis during the follow-up period.

Conclusions

Coccidioidomycosis-related hydrocephalus more often affected young males in the study's cohort, especially those of African and Asian descent. Despite the best medical therapy, there was a high rate of shunt failure due to clogged catheters or valves due to the underlying disease process. Many patients continued to have ventriculomegaly even with adequate CSF diversion. The morbidity and mortality of this chronic disease process must be recognized by the treatment team, and patients should be appropriately counseled.