False-positive Aspergillus galactomannan assay in solid organ transplant recipients with histoplasmosis.

Post-transplantation histoplasmosis may be acquired via inhalation, may result from endogenous reactivation, or may be derived from the allograft. The Histoplasma and Aspergillus enzyme-linked immunoassays are increasingly being relied upon for rapid diagnosis of fungal infections, especially in immunocompromised patients. We describe 4 cases of solid organ transplant recipients who had histoplasmosis and a falsely positive Aspergillus galactomannan (GM) obtained from the serum or bronchoalveolar lavage (BAL) fluid. We also report our experience, testing for Histoplasma antigen (Ag) in specimens positive for Aspergillus GM. From January 2007 through December 2010, of 2432 unique patients who had positive Aspergillus GM tests, 514 (21%) were tested for Histoplasma Ag, and 27 were found to be positive. Most specimens that tested positive for both Aspergillus and Histoplasma were obtained by BAL. False-positive tests for Aspergillus GM can occur in immunosuppressed patients who have histoplasmosis, and may obscure the correct diagnosis.

Unusual case of central vein thrombosis and sepsis.

A patient with Crohn's disease who required placement of a right external jugular vein central catheter for total hyperalimentation is presented. Catheter-induced thrombosis and catheter-associated bacteremia and sepsis subsequently developed. Following the description of the case is a brief discussion of the complications inherent in central line placement, the mechanisms by which thrombosis and sepsis occur, and the measures that can be taken to decrease the incidence of thrombosis and sepsis in central line placement. The management of central venous thrombosis and sepsis is medical and not surgical in nature, and consists of catheter removal, antibiotics, and anticoagulation.

The epidemiology of sharps injuries and splash exposures at a military medical center.

Health care workers (HCWs) are subject to sharps injuries and splash exposures on a daily basis, and are therefore at risk for infection with a number of bloodborne pathogens. We conducted a review of sharps injuries and splash exposures at our institution. Although nursing personnel most often sustained sharps injuries, many HCWs from different patient care occupations are involved, and underreporting obscures the magnitude of the problem. Sharps injuries are most commonly caused by hollow-bore needles, although many devices in the hospital environment are capable of causing injury. Most sharps injuries occur after the device is used, but before disposal. Reducing the number of sharps injuries will require a multifaceted approach including reducing the need for using sharps, better HCW instruction in preventing injuries, and improved instrument design.

Induction of tumor necrosis factor alpha by spherules of Coccidioides immitis.

The cytokine tumor necrosis factor alpha (TNF-alpha) functions as an immunomodulatory protein and as a mediator of cachexia. We report that viable or Formalin-killed spherules of Coccidioides immitis induced the secretion of TNF-alpha by peritoneal-exudate cells from BALB/c mice. The identification of the cytokine as TNF-alpha was based on its lytic activity against the TNF-alpha-sensitive LS murine fibrosarcoma cell line but not the TNF-alpha-resistant LR cell line, its neutralization by rabbit anti-TNF-alpha, and its secretion by peritoneal cells having characteristics of macrophages. The induction of TNF-alpha was to spherules and not to contaminating lipopolysaccharide (endotoxin), as evidenced by the finding that polymyxin B, a reagent that blocks the TNF-alpha-inducing component of lipopolysaccharide, did not negate the production of TNF-alpha in response to spherules, whereas pretreatment of spherules with hyperimmune goat antiserum to spherulin neutralized the induction of TNF-alpha by these cells. The demonstration that C. immitis activates macrophages to secrete TNF-alpha in vitro is a new finding and warrants studies to determine whether this cytokine is produced during active coccidioidomycosis.