Increasing Proportion of High-risk Cytomegalovirus Donor-positive/Recipient-negative Serostatus in Solid Organ Transplant Recipients

BACKGROUND

Cytomegalovirus (CMV) donor-positive/recipient-negative (D+R-) serostatus is independently associated with worse allograft and patient survival across solid organ transplant (SOT) types. We characterized trends in CMV D+R- serostatus among adult SOT recipients performed in the United States.

METHODS

Donor (D) and recipient (R) CMV serostatus and demographic factors were obtained from the Scientific Registry of Transplant Recipients for persons ≥18 y undergoing a first SOT between January 1, 2000, and December 31, 2020. The proportions of D+R- SOTs over time were assessed using Chi square for trend and modeled through 2040. Factors associated with D/R seropositivity were assessed using logistic models.

RESULTS

Among 472 549 SOTs, the average proportion of D+R- SOTs increased significantly among kidney, liver, heart, and lung between 2000 to 2009 and 2010 to 2020: 18.0% to 18.3% ( P  = 0.034), 19.4% to 21.8% ( P  < 0.001), 22.2% to 25.5% ( P  < 0.001), and 23.6% to 27.0% ( P  < 0.001), respectively. The increased proportion over time resulted from a disproportionate increase in R- (34.9% to 37.0% for all organ types, P  < 0.001) and a smaller corresponding change in D+ (60.8% to 60.3%, P  < 0.001).

CONCLUSIONS

The proportion of high-risk CMV D+R- SOTs increased significantly across all organs and is projected to continue to increase. These findings inform population-level strategies to mitigate the negative impact of CMV D+R- in SOT.

Unexpected Cytomegalovirus (CMV) Replication Kinetics in CMV Donor-Seropositive, Recipient-Seronegative Liver Transplant Recipients Receiving Preemptive Antiviral Therapy

BACKGROUND

Detailed cytomegalovirus (CMV) kinetics in donor CMV-seropositive, recipient CMV-seronegative (D+/R-) transplant recipients receiving preemptive therapy (PET) have not been fully defined.

METHODS

The study population consisted of the PET arm of a randomized CMV prevention trial in D+/R- liver transplant recipients. CMV DNA polymerase chain reaction (PCR) assays were performed weekly for 100 days using a sensitive assay. Viral load and clinical parameters were compared for patients with or without high-level increase (defined as higher than the group median log10 increase in viral load from baseline after PET initiation).

RESULTS

Among 79 patients, 93.6% (74/79) developed an increase from baseline viral loads of median 120 IU/mL to 3350 IU/mL; 25.7% (19/74) of the patients had peak levels >10 000 IU/mL. None of the patients with rise in viral load underwent testing for CMV resistance, and viremia resolved with PET with valganciclovir. Patients with high-level increase in viral load had a significantly lower rate of recurrent viremia than those without such increase (16/40 [40%] vs 28/39 [71.8%], respectively; P = .004).

CONCLUSIONS

A majority of D+/R- recipients had a marked increase in viral load after initiation of PET before resolution of viremia. This phenomenon is associated with lower rates of subsequent recurrent viremia and does not necessarily imply antiviral resistance.

Cost-effectiveness of Preemptive Therapy Versus Prophylaxis in a Randomized Clinical Trial for the Prevention of Cytomegalovirus Disease in Seronegative Liver Transplant Recipients With Seropositive Donors

BACKGROUND

The relative costs of preemptive therapy (PET) or prophylaxis for the prevention of cytomegalovirus (CMV) disease in high-risk donor CMV-seropositive/recipient-seronegative (D+/R-) liver transplant recipients have not been assessed in the context of a randomized trial.

METHODS

A decision tree model was constructed based on the probability of outcomes in a randomized controlled trial that compared valganciclovir as PET or prophylaxis for 100 days in 205 D+/R- liver transplant recipients. Itemized costs for each site were obtained from a federal cost transparency database. Total costs included costs of implementation of the strategy and CMV disease treatment-related costs. Net cost per patient was estimated from the decision tree for each strategy.

RESULTS

PET was associated with a 10% lower absolute rate of CMV disease (9% vs 19%). The cost of treating a case of CMV disease in our patients was $88 190. Considering cost of implementation of strategy and treatment-related cost for CMV disease, the net cost-savings per patient associated with PET was $8707 compared to prophylaxis. PET remained cost-effective across a range of assumptions (varying costs of monitoring and treatment, and rates of disease).

CONCLUSIONS

PET is the dominant CMV prevention strategy in that it was associated with lower rates of CMV disease and lower overall costs compared to prophylaxis in D+/R- liver transplant recipients. Costs were driven primarily by more hospitalizations and higher CMV disease-associated costs due to delayed onset postprophylaxis disease in the prophylaxis group.

Trends in Outpatient Antibiotic Prescriptions in the United States During the COVID-19 Pandemic in 2020

This cross-sectional study examines the prescription fills of commonly prescribed outpatient antibiotics in the US through the end of 2020.

Cytomegalovirus Serostatus and Functional Impairment in Liver Transplant Recipients in the Current Era

BACKGROUND

Whether donor (D+) or recipient (R+) cytomegalovirus (CMV) seropositivity is associated with functional impairment in liver transplant recipients is not known.

METHODS

Patients included adult liver transplant recipients in the Organ Procurement and Transplantation Network database transplanted over a five-year period from 1 January 2014-31 December 2018. Functional status in the database was assessed using Karnofsky performance scale. A logistic regression model that controlled for potential confounders was used to examine the association of CMV serostatus and functional status. Variables significantly associated with functional status (p < 0.05) were then used to develop propensity score and propensity score matched analysis was conducted where each patient was compared with a matched-control with the same propensity score.

RESULTS

Among 30,267 adult liver transplant recipients, D+ or R+ patients had significantly lower functional status at last follow-up than the D-R- cohort (OR 0.88, 95% CI 0.80-0.96, p = 0.007). In propensity score matched model, D+ or R+ patients had significantly lower functional status than matched-controls (p = 0.009). D+ or R+ CMV serostatus (p = 0.018) and low functional level (p < 0.001) were also independently associated with infections as cause-of-death.

CONCLUSIONS

D+ or R+ liver transplant recipients had lower functional status and higher risk of deaths due to infections. Future studies are warranted to examine the mechanistic basis of these findings in the setting of transplantation.

Impact of Revised Infectious Diseases Society of America and Society for Healthcare Epidemiology of America Clinical Practice Guidelines on the Treatment of Clostridium difficile Infections in the United States

BACKGROUND

Our objective was to determine if oral vancomycin, fidaxomicin, and oral metronidazole use in the United States changed after publication of revised clinical practice guidelines for Clostridium difficile infection (CDI) in February 2018.

METHODS

We obtained US antibiotic prescription data (IQVIA) from 2006-August 2019 and used guideline-recommended dosing regimens to estimate monthly numbers of 10-day treatment courses of vancomycin, fidaxomicin and metronidazole. Interrupted time-series analyses were performed, adjusted by month. We compared linear trends for monthly numbers of treatment courses in different time periods.

RESULTS

Cumulative treatment courses of oral vancomycin and fidaxomicin increased by 54% (n = 226 166) and 48% (n = 18 518), respectively, in 18 months following guidelines compared with 18 months before; those of oral metronidazole decreased by 3% (n = 238 372). Monthly vancomycin and fidaxomicin use significantly increased throughout the period following revised guidelines (P < .0001 and P = .0002, respectively), whereas that of metronidazole decreased significantly (P < .0001). Monthly vancomycin use increased and metronidazole use decreased to a significantly greater extent after publication of revised guidelines than after publication of clinical trials establishing superiority of vancomycin over metronidazole (P < .0001).

CONCLUSIONS

Revised practice guidelines have had a significant impact on CDI treatment in the US. Clinical trial data used for the revised guidelines were available since 2007-2014 and 2011-2012 for oral vancomycin and fidaxomicin, respectively. Guidelines or guidance documents for treating CDI and other infections should be updated in more timely fashion.

Sustained Reductions in Overall and Unnecessary Antibiotic Prescribing at Primary Care Clinics in a Veterans Affairs Healthcare System Following a Multifaceted Stewardship Intervention

BACKGROUND

Most antibiotic prescribing is in outpatient settings. However, antibiotic stewardship has focused overwhelmingly on hospitalized patients. In a few studies, behavioral interventions decreased unnecessary outpatient prescribing against acute respiratory infections, but data are conflicting on sustained benefits after intervention discontinuation.

METHODS

We conducted a prospective, observational study in 7 primary care clinics, in which an intervention comprised of clinician education, peer comparisons, and computer decision support order sets was directed against all antibiotic prescribing. After 6 months, peer comparisons were discontinued. Antibiotic prescribing was compared in the baseline (January-June 2016), intervention (January-June 2017), and postintervention (January-June 2018) periods.

RESULTS

Mean antibiotic prescriptions significantly decreased from 76.9 (baseline) to 49.5 (intervention) and 56.3 (postintervention) per 1000 visits (35.6% and 26.8% reductions, respectively; P values < .001). The rate of unnecessary antibiotic prescribing (ie, antibiotic not indicated) decreased from 58.8% (baseline) to 37.8% (intervention) and 44.3% (postintervention) (35.7% and 24.7% decreases, respectively; P = .001 and P = .01). Overall, 19.9% (27/136), 36.6% (66/180), and 34.9% (67/192) of antibiotics were prescribed optimally (ie, antibiotics were indicated, and a guideline-concordant agent was prescribed for guideline-concordant duration) during the baseline, intervention, and postintervention periods, respectively (baseline vs intervention and postintervention, P = .001 and P = .003, respectively). Differences between intervention and postintervention periods in overall, unnecessary, or optimal antibiotic prescribing were not significant.

CONCLUSIONS

A multifaceted outpatient stewardship intervention achieved reductions in overall, unnecessary, and suboptimal antibiotic prescription rates, which were sustained for a year after components of the intervention were discontinued. There is opportunity for further improvement, as inappropriate and suboptimal prescribing remained common.

Impact of the Coronavirus Disease 2019 Pandemic on Outpatient Antibiotic Prescriptions in the United States

In April 2020, there were significant reductions in prescription fills of each of the 10 most prescribed outpatient antibiotics in the United States. Monthly azithromycin, amoxicillin-clavulanate, and levofloxacin fills did not rebound significantly from April through July 2020. Coronavirus disease 2019 had an immediate and sustained impact on US outpatient antibiotic prescribing.

Antibiotic Consumption and Stewardship at a Hospital outside of an Early Coronavirus Disease 2019 Epicenter

There are scant data on the impact of coronavirus disease 2019 (COVID-19) on hospital antibiotic consumption, and no data from outside epicenters. At our nonepicenter hospital, antibiotic days of therapy (DOT) and bed days of care (BDOC) were reduced by 151.5/month and 285/month, respectively, for March to June 2020 compared to 2018-2019 (P = 0.001 and P < 0.001). DOT per 1,000 BDOC was increased (8.1/month; P = 0.001). COVID-19 will impact antibiotic consumption, stewardship, and resistance in ways that will likely differ temporally and by region.

Risk Factors for Cytomegalovirus Viremia following Liver Transplantation With a Seropositive Donor and Seronegative Recipient Receiving Antiviral Therapy

BACKGROUND

The risk factors for development of viremia in high-risk donor cytomegalovirus (CMV)-seropositive and recipient CMV-seronegative (D+R-) transplant recipients are incompletely defined.

METHODS

The study population comprised patients in the preemptive therapy (PET) arm of a randomized, controlled trial of PET versus prophylaxis using valganciclovir in D+R- liver transplant recipients. Weekly surveillance monitoring for viremia for 100 days was performed using a sensitive CMV-DNA polymerase chain reaction assays. Risk factors for viremia and time to onset (≤4 vs >4 weeks) of viremia were examined using logistic regression models.

RESULTS

Viremia developed in 84% (79/94) of recipients and older donor age was the only independent factor associated with viremia (odds ratio, 2.20 for each quartile increase in donor age; 95% confidence interval [CI], 1.07-4.52; P = .031). Recipients who developed early-onset viremia (within 4 weeks) also had significantly older donors than those with later-onset viremia (difference in age 10.1 years; 95% CI, 2-19; P = .03).

CONCLUSIONS

Older donor age was an independent predictor of viremia and earlier-onset of viremia in D+R- liver transplant recipients. Future studies should assess the mechanistic links underlying this novel association.

CLINICAL TRIAL REGISTRATION

NCT01552369.

Effect of Preemptive Therapy vs Antiviral Prophylaxis on Cytomegalovirus Disease in Seronegative Liver Transplant Recipients With Seropositive Donors: A Randomized Clinical Trial

IMPORTANCE

Despite the use of a cytomegalovirus (CMV) prevention strategy of antiviral prophylaxis for high-risk CMV-seronegative liver transplant recipients with seropositive donors, high rates of delayed-onset postprophylaxis CMV disease occur. An alternate approach, preemptive therapy (initiation of antiviral therapy for early asymptomatic CMV viremia detected by surveillance testing), has not previously been directly compared with antiviral prophylaxis in these patients.

OBJECTIVE

To compare preemptive therapy with antiviral prophylaxis in CMV-seronegative liver transplant recipients with seropositive donors for the prevention of CMV disease.

DESIGN, SETTING, AND PARTICIPANTS

Randomized clinical trial of preemptive therapy vs antiviral prophylaxis in 205 CMV-seronegative liver transplant recipients with seropositive donors aged older than 18 years. The trial was conducted at 6 academic transplant centers in the United States between October 2012 and June 2017, with last follow-up in June 2018.

INTERVENTIONS

Patients were randomized 1:1 to receive either preemptive therapy (valganciclovir, 900 mg, twice daily until 2 consecutive negative tests a week apart) for viremia detected by weekly plasma CMV polymerase chain reaction for 100 days (n = 100) or valganciclovir, 900 mg, daily for 100 days as antiviral prophylaxis (n = 105).

MAIN OUTCOMES AND MEASURES

The primary outcome was incidence of CMV disease by 12 months, defined as CMV syndrome (CMV viremia and clinical or laboratory findings) or end-organ disease. Secondary outcomes included acute allograft rejection, opportunistic infections, graft and patient survival, and neutropenia.

RESULTS

Among 205 patients who were randomized (mean age, 55 years; 62 women [30%]), all 205 (100%) completed the trial. The incidence of CMV disease was significantly lower with preemptive therapy than antiviral prophylaxis (9% [9/100] vs 19% [20/105]; difference, 10% [95% CI, 0.5% to 19.6%]; P = .04]). The incidence of allograft rejection (28% vs 25%; difference, 3% [95% CI, -9% to 15%]), opportunistic infections (25% vs 27%; difference, 2% [95% CI, -14% to 10%]), graft loss (2% vs 2%; difference, <1% [95% CI, -4% to 4%]), and neutropenia (13% vs 10%; difference, 3% [95% CI, -5% to 12%]) did not differ significantly for the preemptive therapy vs antiviral prophylaxis group, respectively. All-cause mortality at last follow-up was 15% in the preemptive therapy vs 19% in the antiviral prophylaxis group (difference, 4% [95% CI, -14% to 6%]; P = .46).

CONCLUSIONS AND RELEVANCE

Among CMV-seronegative liver transplant recipients with seropositive donors, the use of preemptive therapy, compared with antiviral prophylaxis, resulted in a lower incidence of CMV disease over 12 months. Further research is needed to replicate these findings and assess long-term outcomes.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01552369.

Point-of-use filters for prevention of health care-acquired Legionnaires' disease: Field evaluation of a new filter product and literature review

BACKGROUND

The Centers for Medicare & Medicaid Services requires that health care facilities assess their building water systems and minimize the risk of growth and spread of Legionella and other waterborne pathogens. Increasingly, point-of-use (POU) filters are being used to prevent exposure to these pathogens. This study provides efficacy and performance specifications (membrane size, pore size, and use restrictions), which will aid in selecting POU filters.

METHODS

New faucet and shower filters rated for 62 days of use were evaluated at an acute care facility in Southwestern Ontario, Canada. Five faucets and 5 showers served as controls or were equipped with filters. Hot water samples were collected weekly for 12 weeks and cultured for Legionella, heterotrophic plate count, and Pseudomonas. Literature searches for articles on POU filters used in health care settings were performed using PubMed and Google Scholar. Filter specifications from 5 manufacturers were also compared.

RESULTS

The 62-day POU filters installed on both faucets and showers eliminated Legionella and reduced heterotrophic plate count concentrations for 12 weeks. No Pseudomonas was recovered during this study. Twenty peer-reviewed studies are summarized, and 21 features of 53 POU filters have been compiled.

CONCLUSIONS

The information provides infection preventionists and facility engineers with information to verify claims from manufacturers and compare differences among POU products, including validated efficacy, filter design, and operational specifications.

Improved Antibiotic Prescribing within a Veterans Affairs Primary Care System through a Multifaceted Intervention Centered on Peer Comparison of Overall Antibiotic Prescribing Rates

Reducing inappropriate outpatient antibiotic use is an important national goal. Limited data exist on targeted education and peer comparison of overall antibiotic prescribing rates as an antimicrobial stewardship strategy. Primary care professionals (PCPs) from all seven clinics within our health care system were offered an education session, followed by monthly e-mails with their antibiotic prescribing rate, peer prescribing rates, and a system target. A pre-post analysis was conducted to compare prescribing rates during the intervention period (January to June 2017) to a seasonal baseline (January to June 2016) using a regression model. A random sample of prescriptions was reviewed for adherence to consensus guidelines. Educational sessions were attended by 68.5% (50/73) of PCPs. From the baseline to the intervention period, the mean rate of monthly antibiotic prescriptions declined from 76.9 to 49.5 per 1,000 office visits (35.6% reduction [P < 0.001]). Among reviewed cases, unnecessary antibiotic prescribing declined (58.8% [80/136] versus 38.9% [70/180]; 33.9% reduction [P = 0.0006]), and the rate of optimally prescribed antibiotics increased (19.9% [27/136] versus 30% [54/180]; 50.8% increase [P = 0.05]). If an antibiotic was indicated, there were no significant differences in prescribing of guideline-discordant agents (21.4% [12/56] versus 19.1% [21/110] [P = 0.8]) or guideline-concordant agents for a guideline-discordant duration (38.6% [17/44] versus 39.3% [35/89] [P = 1]). There were significant reductions in azithromycin and fluoroquinolone prescriptions (50.9% and 59.4% [P values of <0.001], respectively), but most prescriptions for these agents in the intervention period remained inappropriate. Initial education followed by monthly peer comparison of overall antibiotic prescribing rates reduced total and unnecessary antibiotic prescribing in primary care clinics.

Unique characteristics of cryptococcosis identified after death in patients with liver cirrhosis: comparison with concurrent cohort diagnosed antemortem

Characteristics of cirrhosis-associated cryptococcosis first diagnosed after death are not fully known. In a multicenter study, data generated as standard of care was systematically collected in 113 consecutive patients with cirrhosis and cryptococcosis followed for 80 patient-years. The diagnosis of cryptococcosis was first established after death in 15.9% (18/113) of the patients. Compared to cases diagnosed while alive, these patients had higher MELD score (33 vs. 22, P = .029) and higher rate of cryptococcemia (75.0% vs. 41.9%, P = .027). Cases diagnosed after death, in comparison to those diagnosed during life were more likely to present with shock (OR 3.42, 95% CI 1.18-9.90, P = .023), require mechanical ventilation at admission (OR 8.5, 95% CI 2.74-26.38, P = .001), less likely to undergo testing for serum cryptococcal antigen (OR 0.07, 95% CI 0.02-0.21, P < .001) and have positive antigen when the test was performed (OR 0.07, 95% CI 0.01-0.60, P = .016). In a subset of cirrhotic patients with advanced liver disease cryptococcosis was first recognized after death. These patients had the characteristics of presenting with fulminant fungemia, were less likely to have positive serum cryptococcal antigen and posed a diagnostic challenge for care providers.

Inflammasome expression and cytomegalovirus viremia in critically ill patients with sepsis

BACKGROUND

CMV viremia is a contributor to poor outcomes in critically ill patients with sepsis.

OBJECTIVES

To assess the expression levels of genes encoding inflammasome-related proteins in the development of CMV viremia in critically ill patients with sepsis.

STUDY DESIGN

A cohort of CMV-seropositive critically ill patients with sepsis due to bloodstream infection underwent weekly testing for CMV viremia. Blood samples to evaluate mRNA levels of genes encoding CASP1, ASC, NLRP1, NLRP3, and NLRP12 were collected at the time of enrollment. Clinical outcomes were assessed at 30days or until death/discharge from ICU.

RESULTS

CMV viremia was documented in 27.5% (8/29) of the patients, a median of 7days after the onset of bacteremia. Patients with sepsis who developed CMV viremia had higher CASP1 although this was not statistically significant (relative mean 3.6 vs 1.8, p=0.13). Development of high grade CMV viremia however, was significantly associated with CASP1; septic patients who developed high grade CMV viremia had significantly higher CASP1than all other patients (relative mean 5.5 vs 1.8, p=0.016).

CONCLUSIONS

These data document possible involvement of inflammasome in the pathogenesis of CMV. Regulating the host immune response by agents that target these genes may have implications for improving CMV-related outcomes in these patients.

Alternative Therapy Use in Liver Transplant Recipients

Background

The extent of use of alternative therapies and the psychosocial variables predictive of their use have not been well defined in liver transplant recipients.

Objective

To determine types of alternative therapies used by liver transplant recipients and to assess psychosocial, behavioral, and quality of life variables associated with the use of alternative therapies in these patients.

Methods

Assessment of types of alternative therapies used, demographic characteristics, satisfaction with social support, coping styles, sense of personal control (mastery), quality of life, and health beliefs in 32 liver transplant recipients.

Results

Overall, 34.4% of the liver transplant recipients used a form of alternative therapy. Herbal products were used by 45% of the alternative therapy users and included milk thistle (silymarin), eclipta, and green beet leaf—all considered “hepatic tonics.” Alternative therapy users tended to have greater problem-focused coping skills than nonusers ( P = .08). Nineteen percent of the patients incurred annual out-of-pocket expense of at least $100 for alternative therapies. Patients incurring out-of-pocket expenses reported better overall health ( P = .02), were more likely to be employed ( P = .025), and had higher mastery scores ( P = .01).

Conclusions

Use of alternative therapies is common after liver transplantation. Herbal products used by liver transplant recipients are disease specific; that is, they claim to promote liver health.

Lack of correlation between Legionella colonization and microbial population quantification using heterotrophic plate count and adenosine triphosphate bioluminescence measurement

This investigation compared biological quantification of potable and non-potable (cooling) water samples using pour plate heterotrophic plate count (HPC) methods and adenosine triphosphate (ATP) concentration measurement using bioluminescence. The relationship between these measurements and the presence of Legionella spp. was also examined. HPC for potable and non-potable water were cultured on R2A and PCA, respectively. Results indicated a strong correlation between HPC and ATP measurements in potable water (R = 0.90, p < 0.001). In the make-up water and two cooling towers, the correlations between ATP and HPC were much weaker but statistically significant (make-up water: R = 0.37, p = 0.005; cooling tower 1: R = 0.52, p < 0.001; cooling tower 2: R = 0.54, p < 0.001). For potable and non-potable samples, HPC exhibited higher measurement variability than ATP. However, ATP measurements showed higher microbial concentrations than HPC measurements. Following chlorination of the cooling towers, ATP measurements indicated very low bacterial concentrations (<10 colony-forming units (CFU)/mL) despite high HPC concentrations (>1000 CFU/mL) which consisted primarily of non-tuberculous mycobacteria. HPC concentrations have been suggested to be predictive of Legionella presence, although this has not been proven. Our evaluation showed that HPC or ATP demonstrated a fair predictive capacity for Legionella positivity in potable water (HPC: receiver operating characteristic (ROC) = 0.70; ATP: ROC = 0.78; p = 0.003). However, HPC or ATP correctly classified sites as positive only 64 and 62% of the time, respectively. No correlation between HPC or ATP and Legionella colonization in non-potable water samples was found (HPC: ROC = 0.28; ATP: ROC = 0.44; p = 0.193).

Role of Environmental Surveillance in Determining the Risk of Hospital-Acquired Legionellosis: A National Surveillance Study With Clinical Correlations

Objective.

Hospital-acquired Legionella pneumonia has a fatality rate of 28%, and the source is the water distribution system. Two prevention strategies have been advocated. One approach to prevention is clinical surveillance for disease without routine environmental monitoring. Another approach recommends environmental monitoring even in the absence of known cases of Legionella pneumonia. We determined the Legionella colonization status of water systems in hospitals to establish whether the results of environmental surveillance correlated with discovery of disease. None of these hospitals had previously experienced endemic hospital-acquired Legionella pneumonia.

Design.

Cohort study.

Setting.

Twenty US hospitals in 13 states.

Interventions.

Hospitals performed clinical and environmental surveillance for Legionella from 2000 through 2002. All specimens were shipped to the Special Pathogens Laboratory at the Veterans Affairs Pittsburgh Medical Center.

Results.

Legionella pneumophila and Legionella anisa were isolated from 14 (70%) of 20 hospital water systems. Of 676 environmental samples, 198 (29%) were positive for Legionella species. High-level colonization of the water system (30% or more of the distal outlets were positive for L. pneumophila) was demonstrated for 6 (43%) of the 14 hospitals with positive findings. L. pneumophila serogroup 1 was detected in 5 of these 6 hospitals, whereas 1 hospital was colonized with L. pneumophila serogroup 5. A total of 633 patients were evaluated for Legionella pneumonia from 12 (60%) of the 20 hospitals: 377 by urinary antigen testing and 577 by sputum culture. Hospital-acquired Legionella pneumonia was identified in 4 hospitals, all of which were hospitals with L. pneumophila serogroup 1 found in 30% or more of the distal outlets. No cases of disease due to other serogroups or species (L. anisa) were identified.

Conclusion.

Environmental monitoring followed by clinical surveillance was successful in uncovering previously unrecognized cases of hospital-acquired Legionella pneumonia.

Evaluation of a new monochloramine generation system for controlling Legionella in building hot water systems

OBJECTIVE

To evaluate the efficacy of a new monochloramine generation system for control of Legionella in a hospital hot water distribution system.

SETTING

A 495-bed tertiary care hospital in Pittsburgh, Pennsylvania. The hospital has 12 floors covering approximately 78,000 m(2).

METHODS

The hospital hot water system was monitored for a total of 29 months, including a 5-month baseline sampling period prior to installation of the monochloramine system and 24 months of surveillance after system installation (postdisinfection period). Water samples were collected for microbiological analysis (Legionella species, Pseudomonas aeruginosa, Stenotrophomonas maltophilia, Acinetobacter species, nitrifying bacteria, heterotrophic plate count [HPC] bacteria, and nontuberculous mycobacteria). Chemical parameters monitored during the investigation included monochloramine, chlorine (free and total), nitrate, nitrite, total ammonia, copper, silver, lead, and pH.

RESULTS

A significant reduction in Legionella distal site positivity was observed between the pre- and postdisinfection periods, with positivity decreasing from an average of 53% (baseline) to an average of 9% after monochloramine application (P<0.5]). Although geometric mean HPC concentrations decreased by approximately 2 log colony-forming units per milliliter during monochloramine treatment, we did not observe significant changes in other microbial populations.

CONCLUSIONS

This is the first evaluation in the United States of a commercially available monochloramine system installed on a hospital hot water system for Legionella disinfection, and it demonstrated a significant reduction in Legionella colonization. Significant increases in microbial populations or other negative effects previously associated with monochloramine use in large municipal cold water systems were not observed.

Predictors of immune reconstitution syndrome in organ transplant recipients with cryptococcosis: implications for the management of immunosuppression

BACKGROUND

Risk factors including how changes in immunosuppression influence the occurrence of immune reconstitution syndrome (IRS) in solid organ transplant (SOT) recipients with cryptococcosis have not been fully defined.

METHODS

SOT recipients with cryptococcosis were identified and followed for 12 months. IRS was defined based on previously proposed criteria.

RESULTS

Of 89 SOT recipients, 13 (14%) developed IRS. Central nervous system (CNS) disease (adjusted odds ratio [AOR], 6.23; P = .03) and discontinuation of calcineurin inhibitor (AOR, 5.11; P = .02) were independently associated with IRS. Only 2.6% (1/13) of the patients without these risk factors developed IRS compared with 18.8% (6/32) with 1 risk factor, and 50% (6/12) with both risk factors (χ(2) for trend, P = .0001). Among patients with CNS disease, those with neuroimaging abnormalities (P = .03) were more likely to develop IRS, irrespective of serum or CSF cryptococcal antigen titers and fungemia. Graft rejection after cryptococcosis was observed in 15.4% (2/13) of the patients with IRS compared with 2.6% (2/76) of those without IRS (P = .07).

CONCLUSIONS

We determined variables that pose a risk for IRS and have shown that discontinuation of calcineurin inhibitors was independently associated with 5-fold increased risk of IRS in transplant recipients with cryptococcosis.

Tuberculosis in solid-organ transplant recipients: disease characteristics and outcomes in the current era

We determined the characteristics of posttransplant tuberculosis and the impact of rifampin-based antituberculosis regimens on outcomes in the current era. Patients comprised 64 transplant recipients with tuberculosis, divided into 2 consecutive cohorts: an earlier cohort (cases occurring from 2003 to 2007) and a later cohort (cases from 2008 to 2011). Patients from the later versus earlier era had tuberculosis develop later after transplant (odds ratio, 1.01; 95% CI, 1.00-1.02; P= .05), were more likely to be liver transplant recipients (odds ratio, 4.52; 95% CI, 1.32-15.53; P= .02), and were more likely to receive tacrolimus-based immunosuppression (odds ratio, 3.24; 95% CI, 1.14-9.19; P= .03). Mortality rate was 10% in the later cohort and 21% in the earlier cohort (P= .20). Rifampin-based treatment was less likely to be used in patients with prior rejection (P= .04). However, neither rejection rate (P= .71) nor mortality (P= .93) after tuberculosis differed between recipients who received rifampin and recipients who did not. Thus, notable changes have occurred in the epidemiological characteristics of tuberculosis in transplant recipients. Overall mortality rate has improved, with about 90% of the patients now surviving after tuberculosis.

Risk factors for acquisition of multidrug-resistant Acinetobacter baumannii among cancer patients

BACKGROUND

Data regarding multidrug-resistant (MDR) Acinetobacter baumannii infections among cancer patients are limited.

METHODS

We conducted a case-control study to investigate the risk factors for acquisition of MDR A baumannii and the outcomes among cancer patients. Cases were inpatients with malignancy who had MDR A baumannii from any cultures between 2008 and 2011. Controls were inpatients with malignancy but no MDR A baumannii.

RESULTS

A total of 31 case patients were matched with 62 control patients. Hematologic malignancy (P = .036), need for dialysis (P = .01), admission for other reasons except elective surgery (P = .03), transfer from other health care facilities (P = .02), prolonged intensive care unit stay (P = .004), mechanical ventilation (P < .001), pressor use (P = .001), tube feeding (P < .001), transfusion (P = .009), and prior antimicrobial use (P < .001) were identified as significant risk factors in univariate analysis. Need for dialysis (odds ratio [OR], 18.23; P = .04) and prolonged intensive care unit stay (OR, 19.28; P = .01) remained significant in multivariate analysis. Lengths of stay were 28 days for the case patients and 10 days for the control patients (P = .001). The 90-day mortality rates were 41.9% and 29.0%, respectively (P = .20).

CONCLUSIONS

Acquisition of MDR A baumannii among cancer patients appears to be associated with general nosocomial infection risk factors rather than underlying malignancies.

Identifying the risk factors for hospital-acquired methicillin-resistant Staphylococcus aureus (MRSA) infection among patients colonized with MRSA on admission

BACKGROUND

Methicillin-resistant Staphylococcus aureus (MRSA) is a major pathogen in hospital-acquired infections. MRSA-colonized inpatients who may benefit from undergoing decolonization have not been identified.

OBJECTIVE

To identify risk factors for MRSA infection among patients who are colonized with MRSA at hospital admission.

DESIGN

A case-control study.

SETTING

A 146-bed Veterans Affairs hospital.

PARTICIPANTS

Case patients were those patients admitted from January 2003 to August 2011 who were found to be colonized with MRSA on admission and then developed MRSA infection. Control subjects were those patients admitted during the same period who were found to be colonized with MRSA on admission but who did not develop MRSA infection.

METHODS

A retrospective review.

RESULTS

A total of 75 case patients and 150 control subjects were identified. A stay in the intensive care unit (ICU) was the significant risk factor in univariate analysis (P<.001). Prior history of MRSA (P=.03), transfer from a nursing home (P=.002), experiencing respiratory failure (P<.001), and receipt of transfusion (P=.001) remained significant variables in multivariate analysis. Prior history of MRSA colonization or infection (P=.02]), difficulty swallowing (P=.04), presence of an open wound (P=.02), and placement of a central line (P=.02) were identified as risk factors for developing MRSA infection for patients in the ICU. Duration of hospitalization, readmission rate, and mortality rate were significantly higher in case patients than in control subjects (P < .001, .001, and <.001, respectively).

CONCLUSIONS

MRSA-colonized patients admitted to the ICU or admitted from nursing homes have a high risk of developing MRSA infection. These patients may benefit from undergoing decolonization.

Prospective observational study of chronic rhinosinusitis: environmental triggers and antibiotic implications

BACKGROUND

A prolonged course of antibiotic therapy is often initiated for chronic rhinosinusitis (CRS) based on symptomatology. We examined differences in clinical manifestations and underlying conditions in patients with symptoms typical for CRS. CT scan abnormality of the sinuses was the gold standard for diagnosis of CRS.

METHODS

We performed a prospective observational study of 125 adults with classic symptoms of CRS undergoing nasal endoscopy and sinus CT.

RESULTS

The patients were classified into 2 groups: (1) those with radiographic evidence of sinusitis by CT (Sx + CT) (75) and (2) those with normal CT scans of the sinus (Sx - CT) (50). Decreased smell was significantly more common in Sx + CT than in Sx - CT patients, (P = .003). Paradoxically, headache, facial pain, and sleep disturbance occurred significantly more frequently in patients with Sx - CT than in patients with Sx + CT (P < .05). The absence of mucopurulence on endoscopy proved to be highly specific for Sx - CT patients (100%). On the other hand, sensitivity was low; only 24% of Sx + CT patients demonstrated mucopurulence by endoscopy. Improvement in response to antibiotics was similar between both CRS categories.

CONCLUSIONS

Most symptoms considered to be typical for CRS proved to be nonspecific. Interestingly, symptoms that were more severe were significantly more likely to occur in younger patients who were Sx - CT. The efficacy of antibiotic therapy was uncertain. We suggest that objective evidence of mucopurulence assessed by endoscopy or CT should be obtained if antibiotics are to be given for prolonged duration. We recommend a moratorium for the widespread practice of a prolonged course of empiric antibiotics in patients with presumed CRS.

Impact of the duration of posttransplant renal replacement therapy on bacterial infections in liver transplant recipients

Whether the duration of renal replacement therapy (RRT) after liver transplantation influences the rate and types of bacterial infections is not known. In this study, 47 of 299 consecutive liver transplant recipients (16%) required posttransplant RRT. The incidence of bacterial infections was higher in the RRT group versus the non-RRT group (8.84 versus 1.38 per 1000 patient days, P < 0.001). In the RRT group, 49% of the patients (23/47) required long-term RRT (≥30 days), and 51% (24/47) required short-term RRT (<30 days). Long-term RRT (hazard ratio = 2.27, 95% confidence interval = 1.16-4.47, P = 0.017) was a significant predictor of infections. Bacteremia and intra-abdominal infections were the most common sources of infections, and Enterobacteriaceae and enterococci were the predominant pathogens in both groups. The mortality rate for patients requiring RRT was higher than the rate for patients not requiring RRT (P < 0.001), but the mortality rates of the short-term RRT group and the long-term RRT group did not significantly differ (P = 0.654). In conclusion, although both short-term RRT and long-term RRT confer a higher risk of bacterial infections, only long-term RRT is a statistically significant predictor of these infections.

Unrecognized pretransplant and donor‐derived cryptococcal disease in organ transplant recipients

BACKGROUND

Cryptococcosis occurring ≤30 days after transplantation is an unusual event, and its characteristics are not known.

METHODS

Patients included 175 solid-organ transplant (SOT) recipients with cryptococcosis in a multicenter cohort. Very early-onset and late-onset cryptococcosis were defined as disease occurring ≤30 days or >30 days after transplantation, respectively.

RESULTS

Very early-onset disease developed in 9 (5%) of the 175 patients at a mean of 5.7 days after transplantation. Overall, 55.6% (5 of 9) of the patients with very early-onset disease versus 25.9% (43 of 166) of the patients with late-onset disease were liver transplant recipients (P = .05). Very early cases were more likely to present with disease at unusual locations, including transplanted allograft and surgical fossa/site infections (55.6% vs 7.2%; P < .001). Two very early cases with onset on day 1 after transplantation (in a liver transplant recipient with Cryptococcus isolated from the lung and a heart transplant recipient with fungemia) likely were the result of undetected pretransplant disease. An additional 5 cases involving the allograft or surgical sites were likely the result of donor&#x2010;acquired infection.

CONCLUSIONS

A subset of SOT recipients with cryptococcosis present very early after transplantation with disease that appears to occur preferentially in liver transplant recipients and involves unusual sites, such as the transplanted organ or the surgical site. These patients may have unrecognized pretransplant or donor-derived cryptococcosis.

Cutaneous cryptococcosis in solid organ transplant recipients

Clinical manifestations, treatment, and outcomes of cutaneous cryptococcosis in solid organ transplant (SOT) recipients are not fully defined. In a prospective cohort comprising 146 SOT recipients with cryptococcosis, we describe the presentation, antifungal therapy, and outcome of cutaneous cryptococcal disease. Cutaneous cryptococcosis was documented in 26/146 (17.8%) of the patients and manifested as nodular/mass (34.8%), maculopapule (30.4%), ulcer/pustule/abscess (30.4%), and cellulitis (30.4%) with 65.2% of the skin lesions occurred in the lower extremities. Localized disease developed in 30.8% (8/26), and disseminated disease in 69.2% (18/26) with involvement of the central nervous system (88.9%, 16/18), lung (33.3%, 6/18), or fungemia (55.6%, 10/18). Fluconazole (37.5%) was employed most often for localized and lipid formulations of amphotericin B (61.1%) for disseminated disease. Overall mortality at 90 days was 15.4% (4/26) with 16.7% in disseminated and 12.5% in localized disease (P = 0.78). SOT recipients who died were more likely to have renal failure (75.0% vs. 13.6%, P = 0.028), longer time to onset of disease after transplantation (87.5 vs. 22.6 months, P = 0.023), and abnormal mental status (75% vs. 13.6%, P = 0.028) than those who survived. Cutaneous cryptococcosis represents disseminated disease in most SOT recipients and preferentially involves the extremities. Outcomes with appropriate management were comparable between SOT recipients with localized and disseminated cryptococcosis.

Geographic differences in disease expression of cryptococcosis in solid organ transplant recipients in the United States

BACKGROUND

Whether there are geographic differences in clinical presentation of cryptococcosis in solid organ transplant (SOT) recipients in the United States (US) is not known.

MATERIAL/METHODS

Patients comprised a cohort of 120 SOT recipients from US transplant centers who fulfilled the EORTC/MSG criteria for cryptococcal disease.

RESULTS

Central nervous system, pulmonary, and cutaneous cryptococcal disease were observed in 51% (61/120), 64% (77/120), and 15% (18/120) of the patients, respectively. Cutaneous disease was documented in 9% (3/32) of the patients from South Atlantic region, 19% (6/32) from Mid Atlantic, 26% (6/23) from Southern, 7% (2/29) from Midwestern, and in 1 of 4 patients from the Northwestern region of the US. When controlled for age, immunosuppressive regimen, type of transplant, and renal failure at baseline, patients from the Southern compared with other regions of the US were significantly more likely to have cutaneous cryptococcal disease (OR 3.8, 95% CI 1.1-14, P=0.045).

CONCLUSIONS

Post-transplant cryptococcosis is more likely to present with cutaneous disease in the Southern region compared with other regions in the US. This predilection for cutaneous cryptococcosis could not be explained on the basis of differences in immunosuppression or the type of transplant. Whether our findings are related to strain-related variations in characteristics of the yeast or other transplant variables remains to be determined.

Preemptive therapy for cytomegalovirus based on real-time measurement of viral load in liver transplant recipients

BACKGROUND

Real-time PCR has emerged as the preferred diagnostic assay for CMV. However, its utility as a preemptive therapy tool for CMV disease and related outcomes in liver transplant recipients has not been fully defined.

METHODS

Patients comprised 117 consecutive liver transplant recipients who underwent CMV surveillance monitoring using real-time PCR. Preemptive therapy with valganciclovir was employed upon detection of viremia. Baseline viral load was considered high based on log values (median).

RESULTS

CMV viremia developed in 54% (63/117) of the patients, including 77% of R-/D+, 63% of R+/D+, 43% of R+/D-, and 10% of R-/D- patients. Overall, 23% (15/63) of the patients had recurrent viremia; R- serostatus (p=0.065) but not initial viral load correlated with recurrent viremia (p=0.80). At 12 months post-transplant, CMV disease occurred in 0.85% (1/117) of the patients (R+/D+recipient). None (0/30) of the R-/D+patients had CMV disease. Patients with CMV viremia treated preemptively did not differ significantly from those who never developed CMV viremia with regards to bacterial or fungal infections, rejection, graft loss, mortality rate, and probability of survival at 12 months (p>0.05 for all variables). The above outcomes also did not differ for patients with high (>1.9 logs) vs. low viral load (<1.9 logs) (p>0.05 for all outcomes).

CONCLUSIONS

Preemptive therapy guided by real-time PCR based monitoring led to outcomes in all patients or in those with high viral loads that were comparable to outcomes in patients who never developed viremia or had low viral loads, respectively. Late-onset CMV disease at 12 months was observed in <1% of all patients.

Severity of illness scoring systems in patients with bacteraemic pneumococcal pneumonia: implications for the intensive care unit care

Severity of illness scoring systems are useful for decisions on the management of patients with community-acquired pneumonia (CAP), including assessing the need for intensified therapy and monitoring, or for intensive care unit (ICU) admission. We compared the accuracy of the Pneumonia Severity Index (PSI), the CURB-65 and CRB-65 score, the modified-American Thoracic Society score (ATS), the IDSA/ATS guidelines and the Pitt Bacteraemia score (PBS) in evaluating severity of illness in 766 patients with bacteraemic pneumococcal pneumonia. We evaluated the sensitivity and specificity, the positive predictive value (PPV) and the negative predictive value (NPV) and the accuracy of the classification in predicting 14-day mortality. The PSI and the IDSA/ATS guidelines were the most sensitive whereas the PBS and modified-ATS scoring systems were the most specific in predicting mortality. The NPV was comparable for all four scoring systems (all above 90%), but the PPV was highest for PBS (54.2%) and lowest for PSI (23.2%). The predictive accuracy and discriminating power as measured by the receiver-operating characteristic (ROC) curve was highest for the PBS. Both the modified-ATS and the PBS scoring systems identified those patients who might benefit most from intensified care and monitoring. The PBS and modified-ATS proved superior to the IDSA/ATS guidelines, CURB-65 and CRB-65 with respect to their specificity and PPV. The low PPV of the PSI rendered it not usable as a parameter for decision-making in severely-ill patients with pneumococcal bacteraemia.

Cryptococcosis in solid-organ, hematopoietic stem cell, and tissue transplant recipients: evidence-based evolving trends

The impact of current transplantation practices on the characteristics of cryptococcosis in solid-organ transplant recipients is not well defined. The incidence of cryptococcal disease among solid-organ transplant recipients has remained unchanged; however, patients are less likely to present with central nervous system or disseminated disease and are more likely to have cryptococcosis limited to the lungs. Additionally, lipid formulations of amphotericin B are now used more frequently, whereas their use in combination with flucytosine has decreased. The overall mortality of cryptococcosis has significantly improved in the current era. Renal failure remains associated with poor outcome, whereas use of lipid formulations of amphotericin B is associated with a higher survival rate. Despite rare infectious complication, certain peculiar attributes of cryptococcal disease in hematopoietic stem cell recipients and tissue transplant recipients warrant recognition.

Prevention of posttransplant cytomegalovirus disease and related outcomes with valganciclovir: a systematic review

The precise impact of valganciclovir as preventive therapy for cytomegalovirus (CMV) in solid organ transplant (SOT) recipients is not fully defined. Data from studies using valganciclovir as preemptive therapy or prophylaxis for CMV in SOT recipients were synthesized for descriptive analysis. CMV disease occurred in 2.6% and 9.9% of the patients receiving valganciclovir as preemptive therapy and prophylaxis, respectively. Although the incidence of early-onset (<or=90 days posttransplant) CMV disease was only 0.8% and 1.2% in all patients and R-/D+ patients receiving valganciclovir prophylaxis, the incidence of late-onset (>90 days posttransplant) CMV disease rose up to 8.9% and 17.7% in the prophylactic group, respectively. On the contrary, no patients developed late-onset CMV disease in preemptive group. Both approaches with valganciclovir have successfully decreased CMV disease in SOT recipients. Late-onset CMV disease is a complication observed uniquely with valganciclovir prophylaxis, particularly in R-/D+ patients, but not with preemptive therapy.

Hepatic iron content and the risk of Staphylococcus aureus bacteremia in liver transplant recipients

Iron is a critical nutrient source and contributes to staphylococcal pathogenesis. We assessed the role of hepatic explant iron overload as a risk factor for Staphylococcus aureus bacteremia in liver transplant recipients. Seven of 13 cases with S aureus bacteremia (53.8%) had hepatic explant iron concentrations that exceeded normal limits (grade > or = 2). Length of posttransplant intensive care unit stay (P= .013) and hepatocellular carcinoma as underlying liver disease (P = .04), but not hepatic explant iron concentration, correlated with a higher risk of S aureus bacteremia after transplantation. However, noncarriers (patients without S aureus nasal carriage) who developed S aureus bacteremia were more likely to have high hepatic iron content; 4 of 7 (57%) noncarriers with high-grade iron content developed S aureus bacteremia but no noncarriers with low-grade iron content did (P = .07). All noncarriers who became infected had high iron content (grade > or = 2) of the hepatic explant. A readily quantifiable assessment of hepatic iron at the time of transplantation can potentially identify patients without carriage who may be at risk for early S aureus bacteremia.

Pulmonary cryptococcosis in solid organ transplant recipients: clinical relevance of serum cryptococcal antigen

BACKGROUND

The role of serum cryptococcal antigen in the diagnosis and determinants of antigen positivity in solid organ transplant (SOT) recipients with pulmonary cryptococcosis has not been fully defined.

METHODS

We conducted a prospective, multicenter study of SOT recipients with pulmonary cryptococcosis during 1999-2006.

RESULTS

Forty (83%) of 48 patients with pulmonary cryptococcosis tested positive for cryptococcal antigen. Patients with concomitant extrapulmonary disease were more likely to have a positive antigen test result (P=.018), and antigen titers were higher in patients with extrapulmonary disease (P=.003) or fungemia (P=.045). Patients with single nodules were less likely to have a positive antigen test result than were those with all other radiographic presentations (P=.053). Among patients with isolated pulmonary cryptococcosis, lung transplant recipients were less likely to have positive cryptococcal antigen test results than were recipients of other types of SOT (P=.003). In all, 38% of the patients were asymptomatic or had pulmonary cryptococcosis detected as an incidental finding. Nodular densities or mass lesions were more likely to present as asymptomatic or incidentally detected pulmonary cryptococcosis than as pleural effusions and infiltrates (P=.008).

CONCLUSIONS

A positive serum cryptococcal antigen test result in SOT recipients with pulmonary cryptococcosis appears to reflect extrapulmonary or more advanced radiographic disease.

Virulence characteristics of Klebsiella and clinical manifestations of K. pneumoniae bloodstream infections

Differences in clinical manifestations are due to virulence factors expressed by the organism.

We studied 455 consecutive episodes of Klebsiella pneumoniae bacteremia occurring in 7 countries. Community-acquired pneumonia and an invasive syndrome of liver abscess, meningitis, or endophthalmitis occurred only in Taiwan and South Africa. Infections by K1 and K2 capsular serotype, the mucoid phenotype, and aerobactin production were important determinants of virulence. The mucoid phenotype was seen in 94% of isolates in patients with community-acquired pneumonia and in 100% of isolates that caused the invasive syndrome in Taiwan and South Africa, compared with only 2% of isolates elsewhere. Mortality of mice injected with mucoid strains (69%) was strikingly higher than that occurring in mice injected with nonmucoid strains (3%, p<0.001). Differences in clinical features of bacteremic infection with K. pneumoniae are due to the virulence factors expressed by the organism.

Valganciclovir as preemptive therapy for cytomegalovirus in cytomegalovirus-seronegative liver transplant recipients of cytomegalovirus-seropositive donor allografts

The efficacy of valganciclovir as preemptive therapy for the prevention of cytomegalovirus (CMV) disease and its impact on indirect sequelae of CMV were assessed in recipient-negative/donor-positive (R-/D+) liver transplant recipients. Of 187 consecutive liver transplant recipients at our institution since July 2001, 36 (19.2%) belonged to the R-/D+ group. Surveillance tests for CMV were performed on all patients at weeks 2, 4, 6, 8, 10,12, and 16. In all, 27 patients with asymptomatic viremia received preemptive therapy with valganciclovir. At a total follow-up of 62.8 patient years (median: 19 months, range: 3 months to 5.6 years), no episodes of CMV disease were documented in these patients. The incidence of rejection, retransplantation, and bacterial or fungal infections and the probability of survival did not differ for R-/D+ patients and all non-R-/D+ patients treated preemptively with valganciclovir (P > 0.20 for all variables). Thus, preemptive therapy with valganciclovir in R-/D+ patients was not associated with CMV disease during the period of surveillance monitoring or at anytime thereafter (late-onset CMV disease). The indirect outcomes with the use of valganciclovir in R-/D+ patients were comparable to the outcomes of other subgroups of liver transplant recipients receiving preemptive therapy.

Antifungal management practices in liver transplant recipients

We sought to determine the approach to antifungal prophylaxis, and diagnostic and therapeutic practices for the management of invasive aspergillosis in liver transplant recipients. Data were collected by an electronic survey questionnaire sent to all active liver transplant programs in North America; 63% (67/106) of the sites completed the survey. Overall, 91% of the sites employed antifungal prophylaxis; 28% used universal prophylaxis and 72% targeted it toward high-risk patients. Fluconazole was the most commonly used agent for universal and targeted prophylaxis. The leading choice for mold-active agents for antifungal prophylaxis was the echinocandins. Combination therapy was used as primary therapy for invasive aspergillosis in 47%, and as salvage in 80%. Thus, a vast majority of the surveyed programs employ antifungal prophylaxis and most use targeted prophylaxis. Consideration of these practices could guide clinical trial design to optimize antifungal prophylaxis in these patients. Our findings also merit investigations to better define the role of diagnostic assays and combination therapeutic strategies for invasive aspergillosis in liver transplant recipients.

A survey of CMV prevention strategies after liver transplantation

The degree of variability in the use of CMV prevention strategies and choice of antiviral regimens among LT centers has not been previously investigated. An electronic survey on current CMV prevention strategies was sent to all US and Canadian LT centers. A total of 58 (53%) centers completed the survey. Most use CMV PCR for screening or diagnosis. Prophylaxis was the most common prevention strategy for all donor/recipient subtypes except D-/R- who often receive no prophylaxis. Prophylaxis was usually given for 3 months after LT with valganciclovir the most frequently used agent. In the small percentage of centers utilizing the preemptive approach, monitoring for CMV was typically performed with PCR for 3 months and valganciclovir was most frequently used for treatment of detectable CMV viremia. In conclusion, the majority of LT centers utilize CMV prophylaxis over other strategies. Valganciclovir is the most commonly used agent for both antiviral prophylaxis and treatment of CMV viremia in the preemptive approach.

Cryptococcus neoformans in organ transplant recipients: impact of calcineurin-inhibitor agents on mortality

Variables influencing the risk of dissemination and outcome of Cryptococcus neoformans infection were assessed in 111 organ transplant recipients with cryptococcosis in a prospective, multicenter, international study. Sixty-one percent (68/111) of the patients had disseminated infection. The risk of disseminated cryptococcosis was significantly higher for liver transplant recipients (adjusted hazard ratio [HR], 6.65; P=.048). The overall mortality rate at 90 days was 14% (16/111). The mortality rate was higher in patients with abnormal mental status (P=.023), renal failure at baseline (P=.028), fungemia (P=.006), and disseminated infection (P=.035) and was lower in those receiving a calcineurin-inhibitor agent (P=.003). In a multivariable analysis, the receipt of a calcineurin-inhibitor agent was independently associated with a lower mortality (adjusted HR, 0.21; P=.008), and renal failure at baseline with a higher mortality rate (adjusted HR, 3.14; P=.037). Thus, outcome in transplant recipients with cryptococcosis appears to be influenced by the type of immunosuppressive agent employed. Additionally, discerning the basis for transplant type-specific differences in disease severity has implications relevant for yielding further insights into the pathogenesis of C. neoformans infection in transplant recipients.

Bacteremia in lung transplant recipients in the current era

Current trends in the epidemiology, outcome and variables influencing mortality in bacteremic lung transplant recipients have not been fully described. We prospectively studied bacteremias in lung transplant recipients in a multicenter study between 2000-2004. Bacteremia was documented in 56 lung transplant recipients, an average of 172 days after transplantation. Multiple antibiotic resistance was documented in 48% of the isolates; these included 57% of the Gram-negative and 38% of the Gram-positive bacteria. Pulmonary infection was the most common source of resistant gram-negative bacteremias. Mortality rate at 28 days after the onset of bacteremia was 25% (14/56). Mechanical ventilation and abnormal mental status correlated independently with higher mortality (p < 0.05 for both variables). Bacteremia remains a significant complication in lung transplant recipients and is associated with considerable mortality. Recognition of variables portending a high risk for antibiotic resistance and for poor outcome has implications relevant for optimizing antibiotic prescription and for improving outcomes in lung transplant recipients.

Invasive aspergillosis in the recipients of liver retransplantation

Retransplantation is a major risk factor for invasive aspergillosis in liver transplant recipients. However, the risk for invasive aspergillosis with time elapsed since retransplantation, clinical characteristics, and outcome of patients who develop this infection after retransplantation of the liver has not been defined. Patients comprised 17 liver retransplant recipients with invasive aspergillosis between 1990 and 2004. Retransplantation was considered early if it was performed within 30 days and late if performed after 30 days of the first or primary transplant. Retransplant recipients comprised 25% of all cases of invasive aspergillosis after liver transplantation. Fifty-three percent of the Aspergillus infections occurred within 30 days, and 76% within 90 days of retransplantation. In all, 53% (9/17) of the patients were late retransplant recipients. Late compared to early retransplant recipients with invasive aspergillosis were more likely to have central nervous system involvement with invasive aspergillosis (56% vs. 0%, P = 0.03). Mortality rate was 100% for late and 63% for early retransplant recipients with Aspergillus infections. In conclusion, time-varying risk for invasive aspergillosis after retransplantation has implications relevant for guiding antifungal prophylaxis. Given a greater risk for disseminated infection and poor outcome in late retransplant recipients with aspergillosis, potent and aggressive antifungal therapy should be considered upfront in these patients.

Systemic and cerebrospinal fluid T-helper cytokine responses in organ transplant recipients with Cryptococcus neoformans infection

BACKGROUND

The role of Th1 and Th2 mediated cytokine responses in the pathogenesis of Cryptococcus neoformans infection in organ transplant recipients has not been defined.

METHODS

We assessed cytokine levels in the sera and CSF collected prospectively at the time of diagnosis of infection in 25 transplant recipients with cryptococcosis. Serum levels were compared with those in healthy individuals and transplant recipients without cryptococcosis. IFN-gamma or IL-12 (Th1)/IL-10 (Th2) ratio < 1.0 was considered a dominant Th2 response.

RESULTS

Cases had lower ratios of IFN-gamma/IL-10 (p = 0.03) and IL-12/IL-10 (p = 0.03) compared to healthy individuals. Cytokine responses, however, did not differ significantly for cases vs. transplant controls. Cases with fungemia compared to those without fungemia tended to have higher serum IL-10 levels (p = 0.07) and lower IL-12/IL-10 ratios (p = 0.06). CSF ratios of IFN-gamma/IL-10 (p = 0.04) and IL-12/IL-10 (p = 0.04) were lower in cases with cryptococcal meningitis compared to those without meningitis; 80% (8/10) of the cases with cryptococcal meningitis vs. 0% (4/4) of those without meningitis had CSF IFN-gamma/IL-10 ratio of < 1.0 (p = 0.015). The levels of IL-10 (p = 0.04) and IFN-gamma (p = 0.04) in the CSF in cases with cryptococcal meningitis were significantly higher than those in their serum, respectively.

CONCLUSIONS

High expression of Th2 phenotype in cryptococcal meningitis and in fungemia suggests that Th dysregulation may contribute to the pathogenesis of cryptococcosis in organ transplant recipients.

Serotype and antimicrobial resistance patterns of Streptococcus pneumoniae isolated from Taiwanese children: comparison of nasopharyngeal and clinical isolates

This report describes the serotypes and antimicrobial resistance patterns of 860 strains of Streptococcus pneumoniae isolated from nasopharyngeal (NP) carriers and clinical specimens collected from Taiwanese children during the years 1997 to 2003. The 6 most common serotypes/groups were 23F, 19F, 6B, 14, 6A, and 3. These accounted for 652/716 (91.1%) of the NP and 131/144 (91.0%) of the clinical isolates. Serotype 23F was the most common isolate in the NP carriers (25.7%, 184/716). Serogroup14 was most common in the clinical isolates (29.2%, 42/144) and the most frequent invasive isolate (43.4%, 33/76). It was more frequently associated with invasive infection than all other serotypes/groups (odds ratio = 7.2; 95% confidence interval, 4.16-12.46; P < .0001). Resistance to macrolides was high in all serotypes/groups, which ranged from 70% to 97%. Resistance to penicillin varied among the 6 leading serotypes/groups, ranging from 3% in serogroup 3 to 99% in serotype 19F. Serotype 23F was most likely to be multidrug resistant to penicillin, macrolides, and chloramphenicol compared with all others (107/150 [71%] versus 105/461 [23%], P < .0001). The potential coverage by the pentavalent and heptavalent vaccines was 83% for all isolates, but was significantly lower for NP than clinical isolates (81% versus 92%, P< .01). These findings provide baseline data to compare trends in the distribution of pneumococcal serotypes and antibiotic resistance patterns with the introduction of childhood pneumococcal vaccination in Taiwan and other countries.

Impact of an aggressive infection control strategy on endemic Staphylococcus aureus infection in liver transplant recipients

BACKGROUND

Methicillin-resistant Staphylococcus aureus has emerged as a leading pathogen in transplant recipients and has become endemic in many institutions where transplantation is performed. The role of active surveillance programs based on the detection of colonization in the prevention of S. aureus infection in liver transplant recipients has not been defined.

METHODS

A total of 47 consecutive patients who underwent liver transplantation during 1996-1999 were compared with 97 patients who received a liver transplant during 2000-2004 after implementation of an intensive intervention program that included use of surveillance cultures to detect nasal and rectal colonization, use of cohorting and contact isolation precautions, and decolonization with intranasal mupirocin therapy.

RESULTS

The rate of new acquisition of S. aureus colonization of nares after transplantation decreased from 45.6% (21 of 46 patients) during the preintervention period to 9.9% (9 of 91 patients) during the postintervention period (P<.001). An increased length of hospital stay (odds ratio, 1.03; 95% confidence interval, 1.01-1.05; P<.002) was associated with new carriage acquisition, and transplantation during the postintervention period (odds ratio, 0.21; 95% confidence interval, 0.08-0.51; P<.001) was independently protective against new carriage. The rate of infection due to S. aureus decreased from 40.4% (19 of 47 patients) during the preintervention period to 4.1% (4 of 97 patients) during the postintervention period (P<.001), and the rate of bacteremia decreased from 25.5% (12 of 47 patients) to 4.1% (4 of 97 patients), respectively (P<.001). Overall, S. aureus infections occurred more frequently among patients with new carriage than among patients who were carriers at the time of transplantation (P<.001) or patients who were noncarriers (P<.001).

CONCLUSIONS

Use of active surveillance cultures to detect colonization and implementation of targeted infection control interventions proved to be effective in curtailing new acquisition of S. aureus colonization and in decreasing the rate of S. aureus infection that was endemic in our population of liver transplant recipients.

Combination of Voriconazole and Caspofungin as Primary Therapy for Invasive Aspergillosis in Solid Organ Transplant Recipients: A Prospective, Multicenter, Observational Study

BACKGROUND

: The efficacy of the combination of voriconazole and caspofungin when used as primary therapy for invasive aspergillosis in organ transplant recipients has not been defined.

METHODS

: Transplant recipients who received voriconazole and caspofungin (n=40) as primary therapy for invasive aspergillosis (proven or probable) in a prospective multicenter study between 2003 and 2005 were compared to a control group comprising a cohort of consecutive transplant recipients between 1999 and 2002 who had received a lipid formulation of AmB as primary therapy (n=47). In vitro antifungal testing of Aspergillus isolates to combination therapy was correlated with clinical outcome.

RESULTS

: Survival at 90 days was 67.5% (27/40) in the cases, and 51% (24/47) in the control group (HR 0.58, 95% CI, 0.30-1.14, P=0.117). However, in transplant recipients with renal failure (adjusted HR 0.32, 95% CI: 0.12-0.85, P=0.022), and in those with A. fumigatus infection (adjusted HR 0.37, 95% CI: 0.16-0.84, P=0.019), combination therapy was independently associated with an improved 90-day survival in multivariate analysis. No correlation was found between in vitro antifungal interactions of the Aspergillus isolates to the combination of voriconazole and caspofungin and clinical outcome.

CONCLUSIONS

: Combination of voriconazole and caspofungin might be considered preferable therapy for subsets of organ transplant recipients with invasive aspergillosis, such as those with renal failure or A. fumigatus infection.