Immune reconstitution inflammatory syndrome in Mycobacterium chimaera mediastinitis: When clinical judgment trumps imaging.

Mycobacterium chimaera has been described in postoperative cardiovascular procedures in patients after an outbreak of contaminated 3T heater-cooler units. Immune reconstitution inflammatory syndrome (IRIS) has been mostly reported in immunocompromised patients, especially HIV after starting therapy. Our case is a 52-year-old immunocompetent male who was diagnosed with M. chimaera mediastinitis a year after Type A dissection repair and was started on quadruple antimicrobial therapy. He clinically improved but 8 months into therapy he presented with a declining kidney function, pancytopenia, and hypercalcemia which after bone marrow and kidney biopsies were attributed to IRIS. Our patient's diagnosis spared him subsequent surgery. IRIS during the treatment of nontuberculous mycobacteria must be suspected even in immunocompetent patients as reaching the diagnosis is very helpful in preventing additional diagnostic and therapeutic measures.

Listeria monocytogenes cholecystitis: a possible new syndrome.

The U.S. Food and Drug Administration recently added potentially fatal Listeria monocytogenes infection to the list of opportunistic infections that can occur in patients who receive tumor necrosis factor inhibitor therapy. In this study, the first reported case of L monocytogenes cholecystitis associated with etanercept use is described. It also appears that tumor necrosis factor inhibitor therapy likely increases the risk for Listeria cholecystitis. Clinicians need to be aware of this association when selecting antimicrobial therapy for these patients.

Clostridium septicum growth from a total knee arthroplasty associated with intestinal malignancy: a case report.

BACKGROUND: Previous reports of infection with Clostridium septicum have identified an unexpected association with concurrent malignancy. The reported rate of associated malignancy has been found to be as high as 81 percent. The purpose of this case report was to present a case of a total knee arthroplasty infected with C. septicum and the subsequent finding of an occult colonic malignancy. CASE PRESENTATION: A 74 year-old man underwent uneventful bilateral total knee arthroplasties. Two weeks post-operatively, he presented with acute swelling, redness and pain of the left knee. Aspiration of the knee was sent for cell count and culture. The cell count demonstrated 39,000 white blood cells per cubic millimeter with 71% of white blood cells identified as neutrophils. Synovial fluid cultures identified the presence of C. septicum, Enterobacter and coagulase negative Staphylococcus. After urgent irrigation and debridement and polyethylene exchange of the affected knee, the patient was placed on intravenous Penicillin G for a period of six weeks. Two weeks into his course of antibiotics, the patient developed hematochezia and was found to have an obstructive colonic malignancy. The patient underwent hemi-colectomy and has since made a complete recovery of both his malignancy and total knee arthroplasty infection. CONCLUSION: Recognition of the association between C. septicum and malignancy is especially important considering the large predicted increase in total joint arthroplasty procedures over the coming decades. In addition to the standard treatment for infection after total joint arthroplasty, identification of Clostridium septicum should initiate a search for associated occult malignancy.

Ritonavir and epidural triamcinolone as a cause of iatrogenic Cushing's syndrome.

Ritonavir is a protease inhibitor (PI) frequently prescribed with highly active antiretroviral therapy. It functions to boost the effectiveness of other PIs as a result of blocking their breakdown by the cytochrome P450 (3A4) pathway. Through this same mechanism, ritonavir has been shown to cause iatrogenic Cushing's syndrome (ICS) in patients using inhaled fluticasone. In addition, a small number of recent cases suggest that ritonavir may also cause this disorder by prolonging the duration of injected corticosteroids, such as triamcinolone. This case report presents a human immunodeficiency virus (HIV) patient taking ritonavir with ICS and secondary adrenal insufficiency, presumably due to systemic absorption and decreased metabolism of an epidural triamcinolone injection. To the authors knowledge, there have only been 4 previously reported cases describing ritonavir-potentiating ICS after receiving a corticosteroid epidural. This provides further proof that caution should be taken with nonparenteral use of triamcinolone in HIV patients on PIs.

Biopsy-proven vancomycin-associated interstitial nephritis and acute tubular necrosis.

Fewer than ten biopsy-proven case reports exist on vancomycin-associated interstitial nephritis (VAIN) and vancomycin-associated acute tubular necrosis (VAATN). Among these, several are confounded by the use of other potentially offending drugs. We report a case of isolated VAIN/VAATN in a patient on no other potentially nephrotoxic agents other than vancomycin. The patient received intravenous vancomycin for coagulase-negative staphylococcus bacteremia. Her baseline serum creatinine of 0.9 mg/dL increased to 9.6 mg/dL after 1 week of therapy during which vancomycin levels peaked at 141 µg/mL. Renal biopsy revealed acute interstitial nephritis with lymphocytic and eosinophilic infiltrate and acute tubular necrosis. Upon discontinuation of vancomycin and administration of prednisone complete renal recovery ensued over a period of 4 weeks.

Patients Hospitalized with pH1N1 Influenza in an Academic Community Medical Center.

BACKGROUND: The emergence of a novel strain of pandemic influenza (pH1N1) in 2009 presented significant challenges to health care facilities worldwide. In our academic community medical center in suburban Philadelphia, we noted our first pH1N1 diagnosis in September 2009. We sought to assess the impact of pH1N1 disease on our hospitalized patient population. METHODS: We prospectively collected clinical and epidemiological data on 29 consecutive patients that were admitted to our hospital with a primary or secondary diagnosis of influenza from October 1-November 30, 2009. Data were obtained through care of the patients and chart review. RESULTS: Prominent symptoms on admission included fever, hypoxia, cough, myalgias, and diarrhea, with leukocytosis and neutrophilia. Pre-existing medical conditions included asthma, pregnancy, immunosuppressive therapy, and sickle cell disease. All but 5 of the patients were under 60 years of age. Three patients had culture-documented bacterial or mycoplasma infections. All but two of the patients received oseltamivir. Six required admission to the intensive care unit but only one patient died. CONCLUSIONS: Our population of hospitalized patients with novel pH1N1 influenza demonstrated many of the features that have been associated with pH1N1 disease in other populations. Most of the patients were women and none of the patients died directly as a complication of influenza. We observed a cluster of patients with a tetrad of features comprising a history of asthma, obesity, female gender, and African-American race. Individuals with this constellation of factors should be specifically targeted for pH1N1 vaccination.

Mycobacterium avium-avium-associated typhlitis mimicking appendicitis in an immunocompetent host.

Mycobacterium avium-intracellulare complex (MAC) primarily causes respiratory infection in patients with underlying lung disease or disseminated disease in immunocompromised patients. We report a unique case of MAC disease in the terminal ileum of a healthy patient, mimicking appendicitis. This case emphasizes the need to further explore MAC pathogenesis in immunocompetent hosts.

Disseminated Nocardia otitidiscaviarum infection in a woman with sickle cell anemia and end-stage renal disease.

Nocardia otitidiscaviarum is an uncommon human pathogen and a rare cause of pulmonary infection and bacteremia. We report a case of N. otitidiscaviarum bacteremia and pulmonary infection in a patient with end-stage renal disease (chronic kidney disease, stage 5) and sickle cell anemia. The epidemiology, pathogenesis, and treatment of Nocardia infections are discussed.

Use of antibacterial agents in renal failure.

This article provides background information on the pharmacokinetics of antibacterial agents in patients with normal and impaired renal function. Tables are provided to allow quick determination of appropriate dosages for varying degrees of renal failure. The use of serum levels, newer strategies for cefazolin, vancomycin, and aminoglycoside dosing, methods of dialysis and associated antibiotics dosage adjustments, and antibiotic toxicity in renal failure are reviewed.