Lack of association between genotypes and haematogenous seeding infections in a large cohort of patients with methicillin-resistant Staphylococcus aureus bacteraemia from 21 Spanish hospitals

There is increasing concern regarding the association between certain methicillin-resistant Staphylococcus aureus (MRSA) genotypes and poor clinical outcome. To assess this issue, a large cohort of 579 subjects with MRSA bacteraemia was prospectively followed from June 2008 to December 2009, in 21 hospitals in Spain. Epidemiology, clinical data, therapy, and outcome were recorded. All MRSA strains were analysed in a central laboratory. Presence of a haematogenous seeding infection was the dependent variable in an adjusted logistic regression model. Of the 579 patients included in the study, 84 (15%) had haematogenous seeding infections. Microdilution vancomycin median MIC (IQR) was 0.73 (0.38-3) mg/L. Most MRSA isolates (n = 371; 67%) belonged to Clonal Complex 5 (CC5) and carried an SCCmec element type IV and agr type 2. Isolates belonging to ST8-agr1-SCCmecIV, ST22-agr1-SCCmecIV and ST228-agr2-SCCmecI--a single locus variant of ST5--accounted for 8%, 9% and 9% of the isolates, respectively. After adjusting by clinical variables, any of the clones was associated with increased risk of haematogenous seeding infections. Higher vancomycin MIC was not identified as an independent risk factor, either. In contrast, persistent bacteraemia (OR 4.2; 2.3-7.8) and non-nosocomial acquisition (3.0; 1.7-5.6) were associated with increased risk.

Serum iron parameters in the early post-transplant period and infection risk in kidney transplant recipients

BACKGROUND

The impact of iron metabolism on the risk of infectious complications has been demonstrated in various immunosuppressed populations. However, no previous studies have assessed this potential association in kidney transplant (KT) recipients.

METHODS

We prospectively analyzed 228 patients undergoing KT at our institution from November 2008 to February 2011. Serum iron parameters (iron level, ferritin, total iron-binding capacity, unsaturated iron-binding capacity, transferrin, and transferrin saturation) were assessed within the first 2 weeks after transplantation (median interval, 3 days; interquartile [Q1 -Q3 ] range, 1-6 days), and before the occurrence of the first infectious episode (median interval, 26 days; Q1 -Q3 range, 11-76 days). Primary outcome was the occurrence of any episode of infection during the first year. Multivariate-adjusted hazard ratios (aHRs) were estimated by Cox regression models.

RESULTS

Patients with ferritin level ≥ 500 ng/mL had higher incidence rates (per 1000 transplant-days) of overall infection (P = 0.017), bacterial infection (P = 0.002), and bloodstream infection (P = 0.011) during the first post-transplant year. One-year infection-free survival rate was lower in these recipients (26% vs. 41%; P = 0.004). On multivariate analysis, after adjusting for potential confounders, ferritin emerged as an independent predictor of overall infection (aHR [per unitary increment], 1.001; P = 0.006), and bacterial infection (aHR [per unitary increment], 1.001; P = 0.020).

CONCLUSION

Monitoring of serum iron parameters in the early post-transplant period may be useful in predicting the occurrence of infection in KT recipients, although further studies should be carried out to confirm this preliminary finding.

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.

Hypocomplementemia in kidney transplant recipients: impact on the risk of infectious complications

The usefulness of monitoring of complement levels in predicting the occurrence of infection in kidney transplant (KT) recipients remains largely unknown. We prospectively assessed serum complement levels (C3 and C4) at baseline and at months 1 and 6 in 270 patients undergoing KT. Adjusted hazard ratios (aHRs) for infection in each posttransplant period were estimated by Cox regression. The prevalence of C3 hypocomplementemia progressively decreased from 21.5% at baseline to 11.6% at month 6 (p = 0.017), whereas the prevalence of C4 hypocomplementemia rose from 3.7% at baseline to 9.2% at month 1 (p = 0.004). Patients with C3 hypocomplementemia at month 1 had higher incidences of overall (p = 0.002), bacterial (p = 0.004) and fungal infection (p = 0.019) in the intermediate period (months 1-6). On multivariate analysis C3 hypocomplementemia at month 1 emerged as a risk factor for overall (aHR 1.911; p = 0.009) and bacterial infection (aHR 2.130; p = 0.014) during the intermediate period, whereas C3 hypocomplementemia at month 6 predicted the occurrence of bacterial infection (aHR 3.347; p = 0.039) in the late period (>6 month). A simple monitoring strategy of serum C3 levels predicts the risk of posttransplant infectious complications in KT recipients.

Limited impact of cytomegalovirus infection in the long-term outcome of renal and liver transplant

BACKGROUND

The strength of the assumed association of CMV and long term deleterious events in solid organ transplant recipients (SOT) is controversial.

OBJECTIVES

The aim of the present study was to evaluate whether viral replication dynamics during CMV infection or CMV disease may correlate not only with graft dysfunction and survival, but also with other potentially related late events in a long-term followed cohort of kidney (KT) and liver (LT) transplant recipients.

STUDY DESIGN

162 SOT (104 kidney, 58 liver) at our institution (2003-2005) with survival over 180 days and a median follow-up of 71 months (9-86) were analyzed. Using a Cox proportional hazard model, CMV infection (including area under the curve of DNAemia[AUC]) and CMV disease in the first 180 days were evaluated as potential predictors of the following late events (>180 days): mortality, graft dysfunction (GD), graft loss (GL), cardiovascular events (CVE), malignant tumors (MT).

RESULTS

CMV infection occurred in 59% and CMV disease in 8%. Late death occurred in 17%, GD in 45.6%, GL in 14.2%, CVE in 10.5% and MT in 9.9%. We found no significant association between the intensity or duration of CMV viremia (AUC, persistent viremia or untreated CMV viremia) or CMV disease and the development of evaluated late events. According multivariate analysis neither CMV infection (hazard ratio [HR] 2.18 95% CI 0.949-5 p = 0.066) nor CMV disease (HR: 1.72; 95% CI 0.59-5 p = 0.31) were significantly correlated with late mortality.

CONCLUSIONS

Our data do not support that CMV infection or CMV disease contribute significantly to long-term deleterious events in SOT.

Reduced incidence of pneumonia in influenza-vaccinated solid organ transplant recipients with influenza disease

Clin Microbiol Infect

Abstract

Whether influenza vaccination influences the severity of illness in cases of clinical failure in solid organ transplant (SOT) recipients receiving influenza vaccine has not been extensively studied. Our goal was to evaluate the frequency of influenza vaccination among SOT recipients with influenza disease and its impact on the illness severity during the 2010–2011 season. Adult SOT recipients with confirmed influenza infection were included from December 2010 to April 2011. Follow‐up data were recorded and antibody titres were determined using a microneutralization assay. Sixty‐four SOT recipients were included in the study, ten (15.6%) with severe disease, requiring admission to intensive care units, of whom four (6.3%) died. In all, 34 (53.1%) received the 2010–2011 seasonal influenza vaccine and 32 (50.0%) received the 2009‐H1N1 pandemic vaccine, and none had detectable antibodies against influenza at the time of diagnosis of influenza infection. Twenty‐three (67.6%) of the patients that received the vaccine required hospital admission and presented less dyspnoea (10, 29.4% versus 14 (50.0%), p 0.09) and pneumonia (8, 23.8% versus 15, 50.0%, p 0.03, relative risk 0.3, 95% CI 0.1–0.9) than unvaccinated patients, with relative risk reductions of 60% and 70%, respectively. Although influenza vaccination confers protection on SOT recipients against developing influenza pneumonia, the rate of clinical failure is still high. New strategies to improve influenza immunization are needed for this group of patients.

Monitoring of immunoglobulin levels identifies kidney transplant recipients at high risk of infection

We aimed to analyze the incidence, risk factors and impact of hypogammaglobulinemia (HGG) in 226 kidney transplant (KT) recipients in which serum immunoglobulin (Ig) levels were prospectively assessed at baseline, month 1 (T(1) ), and month 6 (T(6) ). The prevalence of IgG HGG increased from 6.6% (baseline) to 52.0% (T(1) ) and subsequently decreased to 31.4% (T(6) ) (p < 0.001). The presence of IgG HGG at baseline (odds ratio [OR] 26.9; p = 0.012) and a positive anti-HCV status (OR 0.17; p = 0.023) emerged as risk factors for the occurrence of posttransplant IgG HGG. Patients with HGG of any class at T(1) had higher incidences of overall (p = 0.018) and bacterial infection (p = 0.004), bacteremia (p = 0.054) and acute pyelonephritis (p = 0.003) in the intermediate period (months 1-6). Patients with HGG at T(6) had higher incidences of overall (p = 0.004) and bacterial infection (p < 0.001) in the late period (>6 month). A complementary log-log model identified posttransplant HGG as an independent risk factor for overall (hazard ratio [HR] 2.03; p < 0.001) and bacterial infection (HR 2.68; p < 0.0001). Monitoring of humoral immunity identifies KT recipients at high risk of infection, offering the opportunity for preemptive immunoglobulin replacement therapy.

Cutaneous infection by Phomopsis longicolla in a renal transplant recipient from Guinea: first report of human infection by this fungus

We report the case of a 72-year-old female renal transplant recipient with a nodular lesion in the distal phalange of the third left finger produced by a dematiaceous fungus that was identified as Phomopsis longicolla. She was treated with itraconazole and terbinafine and later with voriconazole, without response. The patient underwent a surgical resection with lesion-free edge and continued on voriconazole. One year later she was asymptomatic and had not developed new lesions.

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.

Bloodstream infections among transplant recipients: results of a nationwide surveillance in Spain

Bloodstream infections (BSIs) are a major cause of morbidity and mortality in transplant recipients. The aim of this study is to describe the incidence, microbiology and outcomes of BSIs in transplant recipients in Spain. The Spanish Network for Research on Infection in Transplantation (RESITRA) is formed by 16 centers with transplant program in Spain. The incidence and characteristics of BSIs in transplant patients were obtained prospectively from the cohort. We included 3926 transplant recipients (2935 solid organ and 991 hematopoietic stem cell transplants). Overall, 730 episodes of BSIs were recorded with an incidence rate ranging from 3 episodes per 10 000 transplant days in kidney recipients to 44 episodes per 10 000 transplant days in allogeneic hematopoietic stem cell transplantation (HSCT). The most frequent sources were intravascular catheters and the most frequent microorganisms isolated were coagulase-negative staphylococci. Crude mortality of BSIs was 7.8%, being highest in liver recipients (16%). Multidrug resistant nonfermentative gram-negative BSIs had significantly worse prognosis than those caused by their susceptible counterparts (p = 0.015), but no differences were found between resistant and susceptible gram-negative enteric bacilli, S. aureus or Candida spp. BSIs are still a major concern in transplant recipients. The increasing isolations of multiresistant microorganisms represent a challenge for the next years.