Hugo Bonatti

Epidemiology and outcome of infections due to Aspergillus terreus: 10-year single centre experience.

Aspergillus terreus, a less common pathogen, appears to be an emerging cause of infection at our institution, the Medical University Hospital of Innsbruck. Thus the epidemiology and outcome of A. terreus infections over the past 10 years was assessed. We analysed 67 cases of proven invasive aspergillosis (IA) according to the European Organisation for Research and Treatment of Cancer/Mycoses Study Group criteria, investigated antifungal susceptibility of amphotericin B (AMB), voriconazole and caspofungin and performed molecular typing of A. terreus. Patients with proven IA caused by A. terreus (n = 32) and non‐A. terreus (n = 35) were evaluated. The two groups were comparable in terms of age, gender, underlying disease, antifungal prophylaxis and duration of neutropenia (P > 0·05). Leukaemia was the most common underlying malignancy. Fungal dissemination occurred in 63% of the patients. Aspergillus terreus infections were associated with a lower response rate to AMB therapy (20%), compared with 47% for patients with non‐A. terreus infections (P < 0·05). In vitro, A. terreus was found to be resistant to AMB and molecular typing discriminated between patients isolates, showing a high strain diversity with 26 distinct types (I‐XXVI) identified by combination of three primers. Aspergillus terreus infections displayed evidence of AMB resistance in vitro and in vivo and were associated with a high rate of dissemination and poor outcome; A. terreus causes systemic infections of endemic character in Tyrol, Austria. The onset of A. terreus infection depends not on the degree of immunosuppression but on environmental Aspergillus spp. exposure.

Effects of Preoperative Skin Preparation on Postoperative Wound Infection Rates: A Prospective Study of 3 Skin Preparation Protocols

OBJECTIVE To compare the effects of different skin preparation solutions on surgical-site infection rates. DESIGN Three skin preparations were compared by means of a sequential implementation design. Each agent was adopted as the preferred modality for a 6-month period for all general surgery cases. Period 1 used a povidone-iodine scrub-paint combination (Betadine) with an isopropyl alcohol application between these steps, period 2 used 2% chlorhexidine and 70% isopropyl alcohol (ChloraPrep), and period 3 used iodine povacrylex in isopropyl alcohol (DuraPrep). Surgical-site infections were tracked for 30 days as part of ongoing data collection for the National Surgical Quality Improvement Project initiative. The primary outcome was the overall rate of surgical-site infection by 6-month period performed in an intent-to-treat manner. SETTING Single large academic medical center. PATIENTS All adult general surgery patients. RESULTS The study comprised 3,209 operations. The lowest infection rate was seen in period 3, with iodine povacrylex in isopropyl alcohol as the preferred preparation method (3.9%, compared with 6.4% for period 1 and 7.1% for period 2; P = .002). In subgroup analysis, no difference in outcomes was seen between patients prepared with povidone-iodine scrub-paint and those prepared with iodine povacrylex in isopropyl alcohol, but patients in both these groups had significantly lower surgical-site infection rates, compared with rates for patients prepared with 2% chlorhexidine and 70% isopropyl alcohol (4.8% vs 8.2%; P = .001). CONCLUSIONS Skin preparation solution is an important factor in the prevention of surgical-site infections. Iodophor-based compounds may be superior to chlorhexidine for this purpose in general surgery patients.

Donor age affects fibrosis progression and graft survival after liver transplantation for hepatitis C

Background. The use of liver allografts from an older donor (OD) (age >50 years) is a widespread strategy to manage the disparity between supply and demand of organs for liver transplantation. This study determines the effect of OD allografts on fibrosis progression and graft survival after liver transplantation in patients with and without infection caused by hepatitis C virus (HCV). Methods. All patients undergoing liver transplantation at our center from March 1998 to December 2001 were analyzed. Protocol liver biopsies were performed at 1, 16, and 52 weeks after transplantation and yearly thereafter. One liver pathologist scored all biopsy specimens for modified hepatic activity index (0–18) and fibrosis (0–6). Results. A total of 402 patients (167 with HCV and 235 without HCV) underwent liver transplantation during the study period. Among patients with HCV, baseline characteristics of OD recipients were similar to younger donor (YD) (age <50 years) recipients. In patients with HCV, graft survival was shorter in OD graft recipients than in YD recipients (P <0.001). In patients without HCV, graft survival was independent of donor age. In patients with HCV, a fibrosis score of 3 or greater was present in 17% of OD recipients at 4 months and in 26% at 12 months after transplantation, compared with 8% of YD recipients at 4 months and 13% at 12 months (P <0.001). Conclusions. Liver transplantation with OD grafts is associated with rapid progression of fibrosis and decreased graft survival in patients with HCV, but not in patients without HCV. OD grafts should be considered preferentially for patients without HCV.

Zygomycosis in Solid Organ Transplant Recipients: A Prospective, Matched Case-Control Study to Assess Risks for Disease and Outcome

BACKGROUND Clinical characteristics, risks, and outcomes in solid organ transplant (SOT) recipients with zygomycosis in the era of modern immunosuppressive and newer antifungal agent use have not been defined. METHODS In a matched case-controlled study, SOT recipients with zygomycosis were prospectively studied. The primary outcome measure was success (complete or partial response) at 90 days. RESULTS Renal failure (odds ratio [OR], 3.17; P = .010), diabetes mellitus (OR, 8.11; P < .001), and prior voriconazole and/or caspofungin use (OR, 4.41; P = .033) were associated with a higher risk of zygomycosis, whereas tacrolimus (OR, 0.23; P = .002) was associated with a lower risk of zygomycosis. Liver transplant recipients were more likely to have disseminated disease (OR, 5.48; P = .021) and developed zygomycosis earlier after transplantation than did other SOT recipients (median, 0.8 vs 5.7 months; P < .001). Overall the treatment success rate was 60%. Renal failure (OR, 11.3; P = .023) and disseminated disease (OR, 14.6; P = .027) were independently predictive of treatment failure, whereas surgical resection was associated with treatment success (OR, 33.3; P = .003). The success rate with liposomal amphotericin B was 4-fold higher even when controlling for the aforementioned variables. CONCLUSIONS The risks identified for zygomycosis and for disseminated disease, including those that were previously unrecognized, have implications for further elucidating the biologic basis and for optimizing outcomes in SOT recipients with zygomycosis.

MR imaging of soft-tissue vascular malformations: diagnosis, classification, and therapy follow-up.

Vascular malformations and tumors comprise a wide, heterogeneous spectrum of lesions that often represent a diagnostic and therapeutic challenge. Frequent use of an inaccurate nomenclature has led to considerable confusion. Since the treatment strategy depends on the type of vascular anomaly, correct diagnosis and classification are crucial. Magnetic resonance (MR) imaging is the most valuable modality for classification of vascular anomalies because it accurately demonstrates their extension and their anatomic relationship to adjacent structures. A comprehensive assessment of vascular anomalies requires functional analysis of the involved vessels. Dynamic time-resolved contrast material-enhanced MR angiography provides information about the hemodynamics of vascular anomalies and allows differentiation of high-flow and low-flow vascular malformations. Furthermore, MR imaging is useful in assessment of treatment success and establishment of a long-term management strategy. Radiologists should be familiar with the clinical and MR imaging features that aid in diagnosis of vascular anomalies and their proper classification. Furthermore, they should be familiar with MR imaging protocols optimized for evaluation of vascular anomalies and with their posttreatment appearances. Supplemental material available at http://radiographics.rsna.org/lookup/suppl/doi:10.1148/rg.315105213/-/DC1.

Molecular Dissection of an Outbreak of Carbapenem-Resistant Enterobacteriaceae Reveals Intergenus KPC Carbapenemase Transmission through a Promiscuous Plasmid

ABSTRACT Carbapenem-resistant Enterobacteriaceae (CRE) have emerged as major causes of health care-associated infections worldwide. This diverse collection of organisms with various resistance mechanisms is associated with increased lengths of hospitalization, costs of care, morbidity, and mortality. The global spread of CRE has largely been attributed to dissemination of a dominant strain of Klebsiella pneumoniae producing a serine β-lactamase, termed K. pneumoniae carbapenemase (KPC). Here we report an outbreak of KPC-producing CRE infections in which the degree of horizontal transmission between strains and species of a promiscuous plasmid is unprecedented. Sixteen isolates, comprising 11 unique strains, 6 species, and 4 genera of bacteria, were obtained from 14 patients over the first 8 months of the outbreak. Of the 11 unique strains, 9 harbored the same highly promiscuous plasmid carrying the KPC gene blaKPC. The remaining strains harbored distinct blaKPC plasmids, one of which was carried in a strain of Klebsiella oxytoca coisolated from the index patient and the other generated from transposition of the blaKPC element Tn4401. All isolates could be genetically traced to the index patient. Molecular epidemiological investigation of the outbreak was aided by the adaptation of nested arbitrary PCR (ARB-PCR) for rapid plasmid identification. This detailed molecular genetic analysis, combined with traditional epidemiological investigation, provides insights into the highly fluid dynamics of drug resistance transmission during the outbreak. IMPORTANCE The ease of horizontal transmission of carbapenemase resistance plasmids across strains, species, and genera of bacteria observed in this study has several important public health and epidemiological implications. First, it has the potential to promote dissemination of carbapenem resistance to new populations of Enterobacteriaceae, including organisms of low virulence, leading to the establishment of reservoirs of carbapenem resistance genes in patients and/or the environment and of high virulence, raising the specter of untreatable community-associated infections. Second, recognition of plasmid-mediated outbreaks, such as those described here, is problematic because analysis of resistance plasmids from clinical isolates is laborious and technically challenging. Adaptation of nested arbitrary PCR (ARB-PCR) to investigate the plasmid outbreak facilitated our investigation, and the method may be broadly applicable to other outbreaks due to other conserved mobile genetic elements. Whether infection control measures that focus on preventing transmission of drug-resistant clones are effective in controlling dissemination of these elements is unknown. The ease of horizontal transmission of carbapenemase resistance plasmids across strains, species, and genera of bacteria observed in this study has several important public health and epidemiological implications. First, it has the potential to promote dissemination of carbapenem resistance to new populations of Enterobacteriaceae, including organisms of low virulence, leading to the establishment of reservoirs of carbapenem resistance genes in patients and/or the environment and of high virulence, raising the specter of untreatable community-associated infections. Second, recognition of plasmid-mediated outbreaks, such as those described here, is problematic because analysis of resistance plasmids from clinical isolates is laborious and technically challenging. Adaptation of nested arbitrary PCR (ARB-PCR) to investigate the plasmid outbreak facilitated our investigation, and the method may be broadly applicable to other outbreaks due to other conserved mobile genetic elements. Whether infection control measures that focus on preventing transmission of drug-resistant clones are effective in controlling dissemination of these elements is unknown.

Diagnosing Invasive Aspergillosis during Antifungal Therapy by PCR Analysis of Blood Samples

ABSTRACT We evaluated the value of Aspergillus PCR as a tool for diagnosing invasive aspergillosis from whole-blood samples during antifungal therapy. In a 3-year study, 36 patients receiving antifungal therapy due to chest radiographic findings highly suggestive of fungal pneumonia were evaluated. The PCR results from whole-blood samples were compared to those obtained from bronchoalveolar lavage fluids and/or tissue specimens. A total of 205 whole-blood samples, 15 fine-needle aspirations or tissue biopsy specimens, and 21 bronchoalveolar lavage fluids and tracheal secretions were analyzed using PCR. Of the 36 patients, 15 had proven, 9 had probable, and 12 had possible invasive Aspergillus infection according to European Organization for Research and Treatment of Cancer/Mycosis Study Group definitions. For patients with proven infection the sensitivity values of PCR in lung and blood samples were 100 and 40%, respectively. The negative predictive value of blood monitoring under conditions of antifungal treatment was 44%. Clearance of fungal DNA from blood was associated with resolution of clinical symptoms in six of nine patients with proven infection. Repeated positive PCR results for Aspergillus were associated with fatal outcome, as three of six patients died. For patients with probable infection the sensitivity values of PCR in lung fluid and blood were 66 and 44%, respectively. The benefit of PCR diagnosis using whole-blood samples is limited when sampling takes place after treatment has been started. Performance of Aspergillus PCR using tissue samples is recommended in addition to microscopic examination and culture technique for sensitive detection of fungal infection.

The Vascular Nature of Hemorrhoids

The arterial blood supply of the internal hemorrhoidal plexus is commonly believed to be associated with the pathogenesis of hemorrhoids. Ultrasound-supported proctoscopic techniques with Doppler-guided ligature of submucosal rectal arteries have been introduced for the therapy of hemorrhoids. The present investigation focuses on caliber and flow changes of the terminal branches of the superior rectal artery (SRA) supplying the corpus cavernosum recti (CCR) in patients with hemorrhoids. Forty-one outpatients (17 female, 24 male; mean age 48 years) with hemorrhoids of Goligher grades I-IV were compared with 17 healthy volunteers (nine female, eight male; mean age 29 years) by means of transperineal color Doppler ultrasound. The mean caliber of the arterial branches in the study group with hemorrhoids was 1.87±0.68 mm (range, 0.6 to 3.60 mm) and 0.92±0.15 mm (range, 0.6 to 1.2 mm) in the control group (P<0.001). The arterial blood flow was significantly higher in patients with hemorrhoids than in the control group (mean 33.9 vs. 11.9 cm/second, P<0.01). Our findings demonstrate that increased caliber and arterial blood flow of the terminal branches of the SRA are correlated with the appearance of hemorrhoids. We suggest that the hypervascularization of the anorectum contributes to the growth of hemorrhoids rather than being a consequence of hemorrhoids. Transperineal color Doppler ultrasound (CDUS) is an appropriate method to assess these findings in patients with hemorrhoids.

Obesity and Site-Specific Nosocomial Infection Risk in the Intensive Care Unit

BACKGROUND Obese patients are at higher than normal risk for postoperative infections such as pneumonia and surgical site infections, but the relation between obesity and infections acquired in the intensive care unit (ICU) is unclear. Our objective was to describe the relation between body mass index (BMI) and site-specific ICU-acquired infection risk in adults. METHODS Secondary analysis of a large, dual-institutional, prospective observational study of critically ill and injured surgical patients remaining in the ICU for at least 48 h. Patients were classified into BMI groups according to the National Heart, Lung and Blood Institute guidelines: <or= 18.5 kg/m(2) (underweight), 18.5-24.9 kg/m(2) (normal), 25-29.9 kg/m(2) (overweight), 30.0-39.9 kg/m(2) (obese), and >or= 40.0 kg/m(2) (severely obese). The primary outcomes were the number and site of ICU-acquired U.S. Centers for Disease Control and Prevention-defined infections. Multivariable logistic and Poisson regression were used to determine age-, sex-, and severity-adjusted odds ratios (ORs) and incidence rate ratios associated with differences in BMI. RESULTS A total of 2,037 patients had 1,436 infection episodes involving 1,538 sites in a median ICU length of stay of 9 days. After adjusting for age, sex, and illness severity, severe obesity was an independent risk factor for catheter-related (OR 2.2; 95% confidence interval [CI] 1.5, 3.4) and other blood stream infections (OR 3.2; 95% CI 1.9, 5.3). Cultured organisms did not differ by BMI group. CONCLUSION Obesity is an independent risk factor for ICU-acquired catheter and blood stream infections. This observation may be explained by the relative difficulty in obtaining venous access in these patients and the reluctance of providers to discontinue established venous catheters in the setting of infection signs or symptoms.

Status 5 Years after Bilateral Hand Transplantation

Graft survival and function early after hand transplantation is good. It remains unknown, however, whether long‐term survival is limited by chronic rejection. We here describe the clinical course and the status 5 years after bilateral hand transplantation with emphasis on immunosuppression (IS), function, morphology and graft vascular changes.