Headaches in a Horseback Rider.

An immunocompetent woman presented with headaches. She previouslyworked at a farm in upstate New York. Brain MRI noted pituitary enlargement and neurosurgerypursued trans-sphenoidal pituitary biopsy. Histopathology revealed ill-defined granulomaswith clusters of yeast, consistent with Histoplasma.

Make Sure You Have a Safety Net: Updates in the Prevention and Management of Infectious Complications in Stem Cell Transplant Recipients.

Hematopoietic stem cell transplant recipients are at increased risk of infection and immune dysregulation due to reception of cytotoxic chemotherapy; development of graft versus host disease, which necessitates treatment with immunosuppressive medications; and placement of invasive catheters. The prevention and management of infections in these vulnerable hosts is of utmost importance and a key "safety net" in stem cell transplantation. In this review, we provide updates on the prevention and management of CMV infection; invasive fungal infections; bacterial infections; Clostridium difficile infection; and EBV, HHV-6, adenovirus and BK infections. We discuss novel drugs, such as letermovir, isavuconazole, meropenem-vaborbactam and bezlotoxumab; weigh the pros and cons of using fluoroquinolone prophylaxis during neutropenia after stem cell transplantation; and provide updates on important viral infections after hematopoietic stem cell transplant (HSCT). Optimizing the prevention and management of infectious diseases by using the best available evidence will contribute to better outcomes for stem cell transplant recipients, and provide the best possible "safety net" for these immunocompromised hosts.

Aspergillus calidoustus case series and review of the literature.

Aspergillus calidoustus, previously classified as Aspergillus ustus, is an emerging pathogen in immunocompromised persons. We describe four recent cases of A. calidoustus and review 37 additional cases of A. calidoustus (n = 8) or A. ustus (n = 29) published through June 2016. Twenty (49%) cases occurred in patients with hematologic malignancy and/or receipt of hematopoietic cell transplantation, and 13 (32%) occurred in solid organ transplant recipients. Antifungal susceptibility was reported in 49% of cases and in 42% treatment failed. Overall mortality was 66% and, where reported, attributable mortality was 30%. A. calidoustus infection is associated with a high mortality rate and frequently displays in vitro antifungal resistance.

AST to ALT Ratio is elevated in disseminated histoplasmosis as compared to localized pulmonary disease and other endemic mycoses.

Severe pulmonary or disseminated histoplasmosis often necessitates presumptive antifungal treatment while awaiting definitive diagnosis. Histoplasma antigen assays have improved sensitivity but results may lag up to 7 days. In order to increase diagnostic certainty, "soft clues" may be looked for in laboratory and radiologic data, such as elevated alkaline phosphatase or ferritin levels and findings of mediastinal adenopathy or hepatosplenomegaly. To determine if elevated aspartate aminotransferase (AST) to alanine aminotransferase (ALT) ratio is specific to histoplasmosis or a non-specific marker for disseminated fungal infection or sepsis in general, we retrospectively examined records of all patients diagnosed with an endemic fungal infection (EFI) at Rush University Medical Center from January of 1997 to October of 2012, and a cohort of septic patients with elevated liver enzymes. We identified 90 cases of EFIs during the study period that met all inclusion criteria (Histoplasma 21, Blastomyces 56, Coccidioides 12, Paracoccidioides 1). We also evaluated 10 control patients with bacterial sepsis. The mean ratio of AST to ALT in patients with disseminated histoplasmosis was 2.69 (95% CI:1.22, 4.16) while for other EFIs, the mean ratio ranged from 0.38 to 1.14 with disseminated coccidioidomycosis and blastomycosis respectively (P < 0.0001). The ratio in patients with bacterial sepsis was 0.84. We propose the use of the AST/ALT ratio as a clinical "soft clue" suggestive of disseminated histoplasmosis in the appropriate host, and to possibly distinguish cross reactivity of the Histoplasma antigen assay with other EFIs.

Disseminated Cryptococcal Disease in a Patient with Chronic Lymphocytic Leukemia on Ibrutinib.

Cryptococcus is a unique environmental fungus that can cause disease most often in immunocompromised individuals with defective cell-mediated immunity. Chronic lymphocytic leukemia (CLL) is not known to be a risk factor for cryptococcal disease although cases have been described mainly in patients treated with agents that suppress cell-mediated immunity. Ibrutinib is a new biologic agent used for treatment of CLL, mantle cell lymphoma, and Waldenstrom's macroglobulinemia. It acts by inhibiting Bruton's tyrosine kinase, a kinase downstream of the B-cell receptor critical for B-cell survival and proliferation. Ibrutinib use has not been associated previously with cryptococcal disease. However, recent evidence suggested that treatments aimed at blocking the function of Bruton's tyrosine kinase could pose a higher risk for cryptococcal infection in a mice model. Here, we report the first case of disseminated cryptococcal disease in a patient with CLL treated with ibrutinib. When evaluating possible infection in CLL patients receiving ibrutinib, cryptococcal disease, which could be life threatening if overlooked, could be considered.

An unusual case of Aspergillus fibrosing mediastinitis.

Fibrosing mediastinitis due to Aspergillus is rare, particularly in the immunocompetent host. Fibrosing mediastinitis due to Aspergillus species in the immunocompetent patient can be indolent and may be treated with antifungal therapy rather than surgery. We present a 78-year-old nonsmoking, nondiabetic woman with chronic fibrosing mediastinitis due to Aspergillus. Multiple attempts at securing a tissue diagnosis were inconclusive. Ultimately, Aspergillus infection was diagnosed by a video-assisted thoracoscopic surgical biopsy. The patient was started on oral voriconazole, and she remains clinically stable with radiographic improvement. A prolonged, perhaps lifelong, course of antifungal therapy is planned.

Interlaboratory comparison of results of susceptibility testing with caspofungin against Candida and Aspergillus species.

Seventeen laboratories participated in a study of interlaboratory reproducibility with caspofungin microdilution susceptibility testing against panels comprising 30 isolates of Candida spp. and 20 isolates of Aspergillus spp. The laboratories used materials supplied from a single source to determine the influence of growth medium (RPMI 1640 with or without glucose additions and antibiotic medium 3 [AM3]), the same incubation times (24 h and 48 h), and the same end point definition (partial or complete inhibition of growth) for the MIC of caspofungin. All tests were run in duplicate, and end points were determined both spectrophotometrically and visually. The results from almost all of the laboratories for quality control and reference Candida and Aspergillus isolates tested with fluconazole and itraconazole matched the NCCLS published values. However, considerable interlaboratory variability was seen in the results of the caspofungin tests. For Candida spp. the most consistent MIC data were generated with visual "prominent growth reduction" (MIC(2)) end points measured at 24 h in RPMI 1640, where 73.3% of results for the 30 isolates tested fell within a mode +/- one dilution range across all 17 laboratories. MIC(2) at 24 h in RPMI 1640 or AM3 also gave the best interlaboratory separation of Candida isolates of known high and low susceptibility to caspofungin. Reproducibility of MIC data was problematic for caspofungin tests with Aspergillus spp. under all conditions, but the minimal effective concentration end point, defined as the lowest caspofungin concentration yielding conspicuously aberrant hyphal growth, gave excellent reproducibility for data from 14 of the 17 participating laboratories.

Trichosporon inkin peritonitis treated with caspofungin.

Trichosporon inkin is one of six pathogenic species of the genus Trichosporon and the etiologic agent of pubic white piedra. Trichosporon species have been reported as a cause of disseminated infections, particularly among immunosuppressed patients. We describe the third reported case of T. inkin peritonitis associated with peritoneal dialysis and the first to be treated with caspofungin.