Comparison of the clinical course of Clostridium difficile infection in glutamate dehydrogenase-positive toxin-negative patients diagnosed by PCR to those with a positive toxin test.

OBJECTIVES: To evaluate the potential role of PCR-based assays in the over-diagnosis of Clostridium difficile infection (CDI) by using a validated diagnostic algorithm in daily clinical practice. METHODS: We performed a retrospective cohort study evaluating all C. difficile-positive stool samples identified at our institution during a 12-month period, to compare outcomes and recurrence rates between patients with a positive enzyme immunoassay (EIA) for both glutamate dehydrogenase (GDH) and toxin A/B ('toxin-positive group'), with those with GDH-positive, toxin-negative samples in whom the diagnosis was made by a positive PCR-based assay ('toxin-/PCR+ group'). Medical records were reviewed by two independent investigators blinded to the mode of diagnosis. RESULTS: We analysed 231 first CDI episodes (106 (45.8 %) in the 'toxin-positive group' and 125 (54.1%) in the 'toxin-/PCR+ group'). Both groups had similar baseline characteristics. Patients in the 'toxin-positive group' presented more frequently with a severe/severe complicated form than those in the 'toxin-/PCR+ group' (36 (33.9%) versus 24 (19.2%); p 0.011) and had more recurrences (27 (25.5%) versus 9 (7.2%); p 0.001). Diagnosis of CDI based on a GDH/toxin-positive EIA independently predicted severe/severe-complicated course (adjusted OR 2.11; 95% CI 1.06-4.22; p 0.033) and recurrence (adjusted OR 3.79; 95% CI 1.65-8.69; p 0.002). There were no differences in all-cause mortality (12.3% versus 12.0%; p 0.95) or CDI-attributable mortality (4.7% versus 4.8%; p 0.93). CONCLUSIONS: Toxin-positive patients were more likely to have severe-complicated forms of CDI and recurrences. Nevertheless, CDI-related complications may still occasionally occur among toxin-negative patients diagnosed by PCR, which stresses the need for individualized clinical evaluation.

Delphi-based study and analysis of key risk factors for invasive fungal infection in haematological patients.

OBJECTIVE: Mortality caused by invasive fungal infections due to filamentous fungi (IFI-FF) is high. Predisposing factors to IFI-FF are multiple and should be stratified. The objective of this study was to identify key risk factors for IFI-FF in onco-haematological patients in different clinical settings. METHODS: Prospective national Delphi study. Risk factors for IFI-FF in patients with onco-haematological diseases were identified by a systematic review of the literature. An anonymous survey was sent by e-mail to a panel of experts. A key risk factor was defined when at least 70% of the surveyed participants assigned a "maximal" or "high" risk. RESULTS: In allogenic stem cell transplantation, 18 of the 42 risk factors analyzed were classified as key risk factors, including neutropenia, previous IFI-FF, grade III/IV acute or extensive chronic graft-versus-host disease (GVHD), umbilical cord blood transplantation, HLA mismatching transplantation, graft failure, absence of HEPA filters, absence of laminar air flow, diagnosis of acute myeloid leukaemia, haploidentical transplantation, anti-TNF-α drugs, alemtuzumab, anti-thymocyte globulin, immunosuppressive prophylaxis for GVHD, lymphocytopenia, cytomegalovirus infection, and proximity to construction areas. In acute leukaemia/myelodysplastic syndrome (AL/MDS), 7 of 25 risk factors were defined as key risk factors, including neutropenia, consolidation therapy without response, induction therapy, antifungal prophylaxis with azoles, proximity to construction areas, and absence of HEPA filters. In lymphoma/multiple myeloma (MM), the five key risk factors among 21 analyzed were use of steroids, neutropenia, progressive disease, anti-CD52 therapies, and proximity to construction areas. CONCLUSIONS: The Delphi method was useful for the classification and stratification of risk factors for IFI-FF in patients with onco-haematological diseases. Identifying key risk factors will contribute to a better management of IFI-FF in this group of patients at high or changing risk.

Management of infection and febrile neutropenia in patients with solid cancer.

An expert group from the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC, for its acronym in Spanish) and the Spanish Society of Medical Oncology (SEOM, for its acronym in Spanish) have reviewed the main aspects to be considered when evaluating patients with solid cancer and infectious complications contained in this article. Recommendations have, therefore, been put forth regarding the prophylaxis of the most prevalent infections in these patients, the use of vaccines, measures to control infection through vascular catheters, and preventing infection in light of certain surgical maneuvers. The following is a revision of the criteria for febrile neutropenia management and the use of colony-stimulating factors and closes with several guidelines for treating the cancer patient with serious infection. The document concludes with a series of measures to control hospital infection.

Influence of antiviral therapy in the long-term outcome of recurrent hepatitis C virus infection following liver transplantation.

INTRODUCTION: Severity of recurrent hepatitis C virus (HCV) infection in liver transplant recipients (LTR) is variable and the influence of different factors, including the administration of antiviral therapy in the long-term outcome is controversial. METHODS: We analyzed the outcome of a cohort of HCV-infected LTR who were transplanted in our institution. Patients were divided into 2 groups (severe and non-severe HCV disease) depending on the presence of a fibrosis score of F ≥ 2 in the Scheuer index and/or fibrosing cholestasic hepatitis (FCH) in a graft biopsy. Risk factors were studied using logistic regression analysis. Survival of patients was estimated using Kaplan-Meier plots. A total of 146 patients were followed for a mean of 58 months. RESULTS: Fifty-six (34%) patients developed severe HCV disease and showed shorter survival (P < 0.024). Donor age (odds ratio [OR]: 1.04; 95% confidence interval [CI]: 1.02-1.06) and pre-transplant viral load (VL) >10(6) UI/mL (OR: 3.5; 95% CI: 1.42-10.61) were the only factors associated with severe HCV infection. Over-immunosuppression (OR: 2.3; 95% CI: 1.2-4.41) was specifically associated with the development of FCH. Overall, patient survival in recipients who received a full course of anti-HCV therapy was higher than in patients who did not complete antiviral therapy (P = 0.004) or received no treatment (P = 0.007). Patients with non-severe HCV infection have a higher probability of receiving a full course of antiviral therapy (P = 0.033). CONCLUSION: In conclusion, donor age, pre-transplant VL, and over-immunosuppression were associated with the long-term development of severe HCV recurrence in liver grafts. Administration of a full course of antiviral therapy was associated with better survival.

Epidemiology, risk factors and impact on long-term pancreatic function of infection following pancreas-kidney transplantation.

Limited information exists about epidemiology and risk factors of infection following pancreas-kidney transplantation and its impact on long-term pancreatic graft function. A retrospective chart review of episodes of severe infection in consecutive pancreas-kidney transplantations in a single institution was performed to assess the epidemiology, risk factors for infection and their impact on the development of pancreatic graft dysfunction. Ninety-four (81%) of 116 recipients (median follow-up of 1492 days; mean 1594) developed 248 episodes of severe infection. Bacterial infections were present in 208 episodes, with 12% of the isolates resistant to antibiotics used in prophylaxis. There were 40 episodes of fungal infection in 32 patients (28%) (mostly Candida spp), and CMV disease appeared in 20 patients (17%), of which 50% appeared after the third month following surgery. The multivariate analysis identified that surgical re-intervention and the use of steroid pulses were independently associated with the development of any infection. Additionally, pre-transplant evidence of peripheral artery disease, a longer cold ischaemia time and high transfusional requirements were associated with fungal infections. Cytomegalovirus (CMV) mismatch was independently related to CMV disease and female sex, and bladder drainage of the exocrine pancreas was associated with urinary tract infection. At the end of follow-up, 29 patients (25%) had developed severe pancreatic graft dysfunction, and fungal infection was independently associated with it. Our study identifies a subset of pancreas-kidney transplant recipients at a higher risk of developing severe infection. Fungal infection is an independent risk factor for the development of severe pancreatic graft dysfunction.

A non-compulsory stewardship programme for the management of antifungals in a university-affiliated hospital.

Antimicrobial stewardship programmes promote excellence in the use of antimicrobials by selecting the appropriate antimicrobial agent and the correct dose, route of administration and duration of treatment. However, there is limited experience with such programmes targeting antifungal treatments. We present the results of a non-compulsory programme for the control of antifungals. For 12 months, prescriptions of oral voriconazole or intravenous voriconazole, caspofungin and liposomal amphotericin B were reviewed, and non-compulsory recommendations were made. The incidence and outcome of fungal infections were examined. The results for the dispensed defined daily doses (DDDs) and expenditure on antifungals were compared with those for the previous 12 months. The number of antifungal treatments reviewed was 662. A recommendation to change treatment was made in 29% of the cases, including a change from intravenous to oral treatment (15%), cessation of antifungal treatment (8%), and a change to fluconazole (6%). The DDDs of intravenous voriconazole and caspofungin were reduced by 31.4% and 20.2%, respectively. The DDDs of oral voriconazole and dispensed vials of liposomal amphotericin B were increased by 8.2% and 13.9%, respectively. Expenditure on antifungals was reduced by US$370681.78 (11.8% reduction). The programme was not related to significant increases in the incidence of candidaemia, percentage of persistent/relapsing candidaemia cases, percentage of fluconazole-resistant Candida species, incidence of infections by filamentous fungi, or 12-month mortality in patients with filamentous fungal infections. In conclusion, a stewardship programme targeting antifungals achieved a reduction in antifungal expenditure without reducing the quality of care provided.

Primary hepatic actinomycosis presenting as purulent pericarditis with cardiac tamponade.

Cardiac tamponade constitutes an exceptional form of actinomycosis. We describe a case of primary hepatic actinomycosis presenting as purulent pericarditis with cardiac tamponade in a 20-year-old patient with previous esophagectomy and colonic interposition, successfully managed by computed tomography-guided percutaneous drainage and a prolonged course of antibiotic treatment. Actinomyces israelii was identified in the pericardial fluid by 16S rRNA gene sequencing. The literature on the simultaneous presentation of cardiac and hepatic actinomycosis is reviewed.

A new strategy of delayed long-term prophylaxis could prevent cytomegalovirus disease in (D+/R-) solid organ transplant recipients.

Long-term prophylaxis against cytomegalovirus (CMV) started immediately after transplantation in (D+/R-) poses a higher risk of late-onset CMV disease. Delayed CMV prophylaxis could allow a transitory exposure of the immune system to CMV, which would let the immune system mount an adequate CMV-specific cytotoxic response in (D+/R-) patients and confer protection against CMV disease. We included all (D+/R-) solid organ transplant recipients (SOT) performed at our institution (January 3/October 6) who received CMV prophylaxis (mainly with oral valganciclovir) during 100 d. In the first period (until December 4), prophylaxis was initiated immediately after transplantation (conventional prophylaxis: CP). Since January 5, it was initiated after 14 d (delayed prophylaxis: DP). Incidence and severity of CMV disease was compared between both groups. A total of 44 SOT recipients were included (CP: 26 and DP: 18). CMV disease was diagnosed in eight patients (18%), seven of 26 (27%) in the CP group, and one of 18 (5.5%) in the DP group (p = 0.07). CMV colitis was reported in five of 26 patients in the CP group (19%), whereas there were no cases of visceral CMV disease in the DP group (p = 0.048). A 14-d delay in the beginning of long-term prophylaxis against CMV in (D+/R-) is safe and could prevent the onset of late-CMV disease.

Preemptive therapy is not adequate for prevention of cytomegalovirus disease in pancreas-kidney transplant recipients.

BACKGROUND: Cytomegalovirus (CMV) remains the most common viral infection after pancreas-kidney transplantation (PKT). Comparative studies about CMV prophylaxis in PKT have not been developed. METHODS: We analyzed CMV disease in a cohort of 84 PKT recipients. All received intravenous ganciclovir during treatment with anti-thymocyte globulin and later one of the following options for pre-transplant CMV-seropositive recipients: (a) no prophylaxis (n=10 patients), (b) preemptive therapy (PT) (n=13), or (c) continuous prophylaxis (CP) for 12 weeks (n=29). Pre-transplant CMV-seronegative recipients received CP (n=21). RESULTS: Eleven patients were excluded because of organ explantation in the first 15 days. Incidence of CMV disease in seropositive recipients was 30% under no prophylaxis, 23% under PT, and 6.9% under CP. Incidence of CMV disease under CP was 33.3% in seronegative recipients. Six of 9 episodes of CMV disease under CP occurred after finishing prophylaxis. Under CP, the incidence of CMV disease was significantly higher in seronegative than in seropositive recipients (P<0.05). CONCLUSION: According to the results of our study, for CMV-seropositive PKT recipients, CP is a better strategy than PT. For CMV-seronegative recipients, 3 months of CP is an inadequate strategy.

Urinary tract infection due to Corynebacterium urealyticum in kidney transplant recipients: an underdiagnosed etiology for obstructive uropathy and graft dysfunction-results of a prospective cohort study.

BACKGROUND: Corynebacterium urealyticum is a cause of urinary tract infection and encrusting cystitis or pyelitis. Information about this infection in renal transplant recipients is based on case reports. We communicate the first prospective epidemiological study for this population. METHODS: We selected a cohort of 163 renal transplant recipients who were screened for urinary tract infection due to C. urealyticum. Long-term incubation and special media were used for culture of C. urealyticum. The cohort was observed for a mean of 26.2 months (standard deviation, 8.7; range, 1-36 months). Risk factors and outcomes were assessed. RESULTS: At baseline, 16 (9.8%) of 163 patients had C. urealyticum bacteriuria (6 were asymptomatic, 9 had acute cystitis, and 1 had encrusting pyelitis). Independent risk factors (assessed by multivariate analysis) for urinary tract C. urealyticum infection were: antibiotic administration during the previous month (odds ratio, 8.04; 95% confidence interval, 1.57-41.06; P = .012), history of nephrostomy (odds ratio, 51.59; 95% confidence interval, 3.62-736.06; P = .004), and skin colonization (odds ratio, 208.35; 95% confidence interval, 21.54-2015.22; P< .001). Presence of urinary tract infection symptoms for >1 month (odds ratio, 27.7; 95% confidence interval, 2.55-300.5; P = .006) and obstructive uropathy (odds ratio 25.9; 95% confidence interval, 4.43-152.31; P < .001) were more frequent during follow-up in patients with C. urealyticum bacteriuria. CONCLUSIONS: When specifically tested for, C. urealyticum bacteriuria is more prevalent than previously thought in renal transplant recipients, and it is closely related to obstructive uropathy. Future studies are necessary to establish the relevance of treating the infection during follow-up after renal transplantation.

Incidence, clinical characteristics and risk factors of late infection in solid organ transplant recipients: data from the RESITRA study group.

Information describing the incidence and clinical characteristics of late infection (LI) in solid organ transplantation (SOT) is scarce. The aim of this study was to define the incidence, clinical characteristics and risk factors for LI (>6 months) as compared with infection in the early period (<6 months) after SOT. By the online database of the Spanish Network of Infection in Transplantation (RESITRA) we prospectively analyzed 2702 SOT recipients from September 2003 to February 2005. Univariate and multivariate analysis using logistic regression were performed to calculate the risk factors associated with the development of LI. A total of 131 patients developed 176 LI episodes (8%). Global incidence of LI was 0.4 per 1000 transplant-days, ranging from 0.3/1000 in kidney transplants to 1.4 in lung transplants. Independent risk factors for LI in were: acute rejection in the early period (OR 1.5; CI 95%: 1.1-2.3), chronic graft malfunction (OR 2; CI 95%: 1.4-3), re-operation (OR 1.9; CI 95%: 1.3-2.8) relapsing viral infection apart from CMV (OR 1.9; CI 95%: 1.1-3.5), previous bacterial infection (OR 1.8; CI 95%: 1.2-2.6) and lung transplantation (OR 4.5; CI 95%: 2.6-7.8). Severe LI occurs in a subgroup of high-risk SOT recipients who deserve a more careful follow-up and could benefit from prolonged prophylactic measures similar to that performed in the early period after transplantation.

[Individualized evaluation of the risk of infections in the oncohematologic patient]. / Evaluación individualizada del riesgo de infecciones en el paciente oncohematológico.

In order to take the best approach to infection in the oncohematologic patient with fever, it is important to know not only how profound the neutropenia is and how long the patient has had it, but also the characteristics of the underlying disease, the immunosuppressive therapy received and the type of hematopoietic stem/progenitor cell transplantation performed. Moreover, is important to consider if these patients have any personal or familial history of infectious diseases. All these aspects let us calculate the net state of immunosuppression and the risk of infection, and provide us with information about the most probable etiology in each case and the best prophylaxis and treatment. In this study we review the more important advances in chemotherapy in recent years that will make it necessary in the future to change our prophylactic guidelines for more effective prevention of infection in the oncohematologic patient.

Accuracy of blood culture for early diagnosis of mediastinitis in febrile patients after cardiac surgery.

Postsurgical mediastinitis (PSM) remains a major cause of morbidity and mortality in patients undergoing cardiac surgery procedures. Although prompt diagnosis is crucial in these patients, neither clinical data nor imaging techniques have shown enough sensitivity or specificity for early diagnosis of PSM. The aim of the present study was to assess the validity of blood cultures as a diagnostic test for the early detection of PSM in patients who become febrile after cardiac surgery procedures. During a 4-year period (1999-2002), patients who developed fever (>37.8 degrees C) in the first 60 days after a cardiac surgery procedure were evaluated. Blood cultures were drawn from these patients. PSM was defined as deep infection involving retrosternal tissue and/or the sternal bone directly observed by the surgeon and confirmed microbiologically. Three criteria for positivity of blood cultures were applied: bacteremia, staphylococcal bacteremia, or Staphylococcus aureus bacteremia. For purposes of the analysis, a positive blood culture in patients with PSM was considered a true-positive test and a negative blood culture a false-negative test. Otherwise, in febrile patients without PSM in the postsurgery period, a positive blood culture was considered a false-positive test and a negative blood culture a true-negative test. Blood cultures were drawn from 266 febrile patients in the postsurgery period. PSM occurred in 38 patients (26 cases due to S. aureus, 8 to Staphylococcus epidermidis, 3 to gram-negative enteric bacteria, and one to Pseudomonas aeruginosa). Within the 60-day postsurgical period, blood culture as a diagnostic test was most accurate in patients with S. aureus bacteremia, providing 68% sensitivity, 98% specificity, a positive predictive value of 87%, and a negative predictive value of 95%. If the analysis was limited to the period during which patients are at maximum risk for PSM (day 7-20), the values in patients with S. aureus bacteremia were as follows: 73% sensitivity, 98% specificity, 90% positive predictive value, and 93% negative predictive value. Blood culture is an accurate test for the early diagnosis of PSM in febrile patients after cardiac surgery, particularly in institutions where S. aureus is prevalent in this context. A negative blood culture practically excludes PSM and, during the period of maximum risk for PSM, the presence of S. aureus bacteremia should compel early surgical management.

Clinical significance of donor-unrecognized bacteremia in the outcome of solid-organ transplant recipients.

We evaluated the clinical significance of unrecognized bacteremia in the organ donor (i.e., blood culture results that were reported to be positive after transplantation) on the outcome of transplant recipients. Twenty-nine of 569 liver and heart donors (5%) had bacteremia at the time of organ procurement, but there were no documented instances of transmission of the isolated bacteria from the donor to the recipient. Unrecognized bacteremia in the donor does not have a negative clinical impact on the outcome of organ transplant recipients.