Early infections in patients undergoing bone marrow or blood stem cell transplantation--a 7 year single centre investigation of 409 cases

Dental evaluation and clearance prior to allogeneic hematopoietic cell transplantation

INTRODUCTION

Dental examination and stabilization are performed prior to allogeneic hematopoietic cell transplantation to decrease infection risk during neutropenia. Burden of dental disease and treatment need is not well characterized in this population.

OBJECTIVES

This report describes the dental status of a cohort of patients within the Chronic Graft-versus-Host Disease Consortium and treatment rendered prior to transplant.

METHODS

The cohort included 486 subjects (Fred Hutchinson: n = 245; Dana-Farber: n = 241). Both centers have institutional-based dental clearance programs. Data were retrospectively abstracted from medical records by calibrated oral health specialists.

RESULTS

The median age at transplant was 55.9 years, 62.1% were male, and 88% were white. Thirteen patients were edentulous (2.7%). The mean teeth among dentate patients before clearance was 26.0 (SD, 4.6). Dental findings included untreated caries (31.2%), restorations (91.6%), endodontically treated teeth (48.1%), and dental implants (5.7%). Pretransplant procedures during clearance included endodontic therapy (3.6%; mean = 0.1 teeth), restorations (25.1%; mean = 0.7), dental prophylaxis (59.2%), scaling/root planing (5.1%), and extraction (13.2%; mean = 0.3). The mean teeth after clearance was 25.6 (SD, 5.0).

CONCLUSIONS

Retrospective analysis of pre-AlloHCT dental data in subjects at two large transplant centers identified low levels of dental need. Findings suggest high access to care.

Nanopore-Targeted Sequencing Improves the Diagnosis and Treatment of Patients with Serious Infections

Serious infections are characterized by rapid progression, poor prognosis, and difficulty in diagnosis. Recently, a new technique known as nanopore-targeted sequencing (NTS) was developed that facilitates the rapid and accurate detection of pathogenic microorganisms and is extremely suitable for patients with serious infections. The aim of our study was to evaluate the clinical application of NTS in the diagnosis and treatment of patients with serious infections. We developed an NTS technology that could detect microorganisms within a 6-h window based on the amplification of the 16S rRNA gene of bacteria, the internal transcribed spacer region of fungi, and the rpoB gene of Mycobacterium. The NTS detection results were compared with those of blood cultures and anal swabs from 50 patients with blood diseases suffering serious infections. The patient's condition before and after NTS was compared. The response rate and the infection-related mortality after the adjustment of antibiotics based on NTS were calculated. The positivity rate of pathogens was highest in NTS (90%), followed by blood culture (32.6%) and anal swabs (14.6%). After adjusting antibiotics for bacteria and fungi detected by NTS, the patients' condition improved significantly. Moreover, the response rate of anti-infective treatment based on NTS was 93.02% (40/43), and infection-related mortality was reduced to 0. NTS is an effective method to identify pathogens in the blood specimens of patients with serious infections and can guide anti-infection treatment and reduce infection-related mortality. IMPORTANCE We introduce the application of NTS in blood samples of patients with serious infections and expound the efficiency and accuracy of NTS in detecting pathogenic microorganisms. Our work builds on the considerable interest of the scientific community in the management of serious infection. This issue is becoming more pressing, especially since the incidence of blood diseases is increasing year by year and hematopoietic stem cell transplantation (HSCT) has been widely used in benign and malignant blood diseases in recent years. The infection progression of these patients is faster, and the study further demonstrates the effectiveness of NTS in guiding the diagnosis and treatment of patients with severe infections. We firmly believe that this method will guide clinicians to adjust anti-infection strategies and bring significant benefits to patients, and our study will have implications for the future clinical application of NTS in all kinds of patients with serious infections.

Direct DNA Sequencing-Based Analysis of Microbiota Associated with Hematological Malignancies in the Eastern Province of Saudi Arabia

Introduction

Bloodstream infections (BSI) among patients with hematological malignancies (HM) could predispose them to higher morbidity and mortality for various underlying conditions. Several microorganisms, either pathogenic or opportunistic normal human flora, could cause severe bacteremia and septicemia. While conventional methods have their own limitations, molecular methods such as next-generation sequencing (NGS) can detect these blood infections with more reliability, specificity, and sensitivity, in addition to information on microbial population landscape. Methodology. Blood samples from HM patients (n = 50) and volunteer blood donor control individuals with no HM (n = 50) were subjected to 16S rRNA gene amplification using standard PCR protocols. A metagenomic library was prepared, and NGS was run on a MiSeq (Illumina) sequencer. Sequence reads were analyzed using MiSeq Reporter, and microbial taxa were aligned using the Green Genes library.

Results

82% of the patients showed BSI with Gram-negative bacteria as the most predominant group. E. coli comprised a major chunk of the bacterial population (19.51%), followed by K. pneumoniae (17.07%). The CoNS and Viridans Streptococci groups are 17.07% and 14.63%, respectively. Other major species were S. aureus (9.75%), P. aeruginosa (7.31%), A. baumannii (4.87%), E. cloacae (4.87%), and P. mirabilis (4.87%). 34.14% of the cases among patients showed a Gram-positive infection, while 14.63% showed polymicrobial infections.

Conclusion

Most of the BSI in patients were characterized by polymicrobial infections, unlike the control samples. Molecular methods like NGS showed robust, fast, and specific identification of infectious agents in BSI in HM, indicating the possibility of its application in routine follow-up of such patients for infections.

Infections after hematopoietic cell transplantation are not a burden for mortality at a limited-resource center in a developing country

BACKGROUND

Hematopoietic cell transplantation (HCT) outcomes, including infectious complications, change between centers and countries. Thus, the aim of this study was to report the incidence of infections and isolated pathogens among recipients of HCT and the association with mortality at a tertiary referral center in Mexico.

METHODS

Two hundred and eighty-two patients undergoing autologous or allogeneic HCT between January 2005 and December 2018 at the National Institute of Medical Sciences and Nutricion Salvador Zubiran were included.

RESULTS

In autologous HCT (n = 176), within the preengraftment and the early postengraftment, 130 (74%) and 31 (18%) recipients presented infections, respectively. Within the preengraftment, the early postengraftment, and the late postengraftment, 81 (76%), 34 (33%), and 58 (60%) allogeneic HCT recipients presented infections, respectively. Non-relapse mortality (NRM) as a result of infections occurred in 1 (0.6%) and 5 (5%) autologous and allogeneic HCT recipients, respectively.

CONCLUSIONS

Our results demonstrated that despite our limited resources, infections were not a significant burden for NRM among HCT recipients. More importantly, the isolation rates were higher than international studies, which could be explained by the existence of a specialized infectious diseases department and laboratory, which we consider key elements for the establishment of an HCT program worldwide.

Stenotrophomonas maltophilia colonization during allogeneic hematopoietic stem cell transplantation is associated with impaired survival

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) offers potential cure to acute myeloid leukemia (AML) patients. However, infections with commensal bacteria are an important cause for non-relapse mortality (NRM). We have previously described the impact of multidrug-resistant organism (MDRO) colonization on the survival of allo-HSCT patients. In the aforementioned publication, according to consensus, we there did not consider the opportunistic gram-negative bacterium Stenotrophomonas maltophilia (S. maltophilia) to be an MDRO. Since rate of S. maltophilia colonization is increasing, and it is not known whether this poses a risk for allo-HSCT patients, we here analyzed here its effect on the previously described and now extended patient cohort. We report on 291 AML patients undergoing allo-HSCT. Twenty of 291 patients (6.9%) were colonized with S. maltophilia. Colonized patients did not differ from non-colonized patients with respect to their age, remission status before allo-HSCT, donor type and HSCT-comorbidity index. S. maltophilia colonized patients had a worse overall survival (OS) from 6 months up to 60 months (85% vs. 88.1% and 24.7% vs. 59.7%; p = 0.007) due to a higher NRM after allo-HSCT (6 months: 15% vs. 4.8% and 60 months: 40.1% vs. 16.2% p = 0.003). The main cause of mortality in colonized patients was infection (46.2% of all deaths) and in non-colonized patients relapse (58.8% of all deaths). 5/20 colonized patients developed an invasive infection with S. maltophilia. The worse OS after allo-HSCT due to higher infection related mortality might implicate the screening of allo-HSCT patients for S. maltophilia and a closer observation of colonized patients as outpatients.

Fungal infections in hematopoietic stem cell transplantation in children at a pediatric children's hospital in Argentina

Our primary objective was to describe the incidence of proven or probable invasive fungal infections (IFIs), a devastating complication of hematopoietic stem cell transplant (HSCT), in HCST in a middle-income country. Secondary objectives were to describe factors associated with IFIs and outcomes. In this single center retrospective study, pediatric patients who underwent a first allogeneic or autologous HSCT from 1998 to 2016 were included. Of the 251 HSCT recipients: 143 transplants were allogeneic and 108 were autologous. Overall, 23 (9%) experienced an IFI, mostly due to yeasts (83%). IFIs were more common in allogeneic HSCT (18/143, 13%) than in autologous HSCT (5/108, 5%; P = .045). Of the 23 patients with IFIs, 14 (61%) died, but only 1 directly from IFI (pulmonary aspergillosis). Overall survival at 3 years was 0.42 ± 0.11 in patients with IFIs and 0.60 ± 0.37 in those without IFIs (P = .049). In Argentina, IFIs during HSCT are common. Recipients of allogeneic HSCT are at higher risk, and IFI is associated with reduced overall survival. Future work should focus on interventions to reduce and improve IFI outcomes in children undergoing transplants in low- and middle-income countries.

Rates of Microbiologically Diagnosed Infection and Pathogen Detection in Hematopoietic Stem Cell Transplant Patients

Infections remain a significant cause of mortality in hematopoietic stem cell transplant patients. Evaluations of causes of infection are often unrevealing, and at some sites, increasing rates of antimicrobial resistance have been noticed. We performed a retrospective analysis of infection rates and microbiologic testing yield, or percent of tests ordered to diagnose an infection, in the first 100 days of 30 allogeneic and 56 autologous stem cell transplants performed at San Antonio Military Medical Center from July 2011 to April 2014. Blood stream infections were diagnosed in 11.6% with a yield of 6%. Urinary tract infections were diagnosed in 2.3% with a yield of 3%. Clostridium difficile infections were diagnosed in 9.3% and testing yield was 6%. Incidence of respiratory viruses was 5.8% with 4 rhinoviruses/enteroviruses and 1 influenza virus identified. One Proteus mirabilis urinary isolate was an extended spectrum beta-lactamase producer. Five patients, 13% of allogeneic and 4% of autologous patients, died within the first 100 days post-transplantation. History of bacteremia was present in 60% of patients who died; however, only one died due to a microbiologically diagnosed infection. Improved diagnostic tests and methods are needed to increase yield of detection of infection in hematopoietic stem cell transplant patients.

Clinical impact of colonization with multidrug-resistant organisms on outcome after allogeneic stem cell transplantation in patients with acute myeloid leukemia

BACKGROUND

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a curative treatment option for patients with acute myeloid leukemia (AML). During transplantation, patients undergo a period of severe neutropenia, which puts them at high risk for infectious complications. However, the impact of patient colonization with multidrug-resistant organisms (MDRO) on overall survival remains unclear.

METHODS

In this retrospective, single-center study, the authors analyzed data from 264 patients with AML who underwent a first allo-HSCT between January 2006 and March 2016 at their institution. Primary endpoints were overall survival and nonrelapse-related mortality.

RESULTS

One hundred forty-two of 264 patients (53.8%) were colonized by at least 1 MDRO, mainly with vancomycin-resistant Enterococcus faecalis/faecium (n = 122). The characteristics of colonized patients did not differ from those of MDRO-negative patients with respect to median age (53.5 vs 53 years), cytogenetic risk according to European LeukemiaNet criteria, remission status before allo-HSCT (first or second complete remission: 55.7% vs 60.7%, respectively; active disease: 44.4% vs 39.3%, respectively), donor type, or hematopoietic cell transplantation-comorbidity index (HCT-CI). Compared with noncolonized patients, MDRO-positive patients had an inferior probability of survival at 5 years (43.3% vs 65.5%; P = .002), primarily because of a higher cumulative incidence of nonrelapse-related mortality (33.9% vs 9.4%; P < .001). Death caused by infections occurred in 15.5% of colonized patients versus 4.9% of noncolonized patients. There was no difference in the cumulative incidence of relapse in MDRO-positive versus MDRO-negative patients (33.8% vs 42.1%, respectively; P = .798).

CONCLUSIONS

The current data emphasize the importance of regular MDRO screenings and prompt further investigations into the impact of colonization with MDRO on the immune system after allo-HSCT. Cancer 2018;124:286-96. © 2017 American Cancer Society.

Low circulating mannan-binding lectin levels correlate with increased frequency and severity of febrile episodes in myeloma patients who undergo ASCT and do not receive antibiotic prophylaxis

Patients with multiple myeloma (MM) who undergo autologous stem cell transplantation (ASCT) are susceptible to severe infections. Low levels of circulating mannan-binding lectin (MBL) are associated with increased risk of infection. In this prospective study, we evaluated 100 patients who underwent ASCT regarding the effect of MBL on the incidence and severity of febrile episodes. Seventeen patients had MBL levels <500 ng/mL (11 received antibiotic prophylaxis and 6 did not). Although there was no statistical difference regarding the development of febrile episodes between patients with low and normal MBL, among 17 patients with low MBL levels, six out of eleven patients who received antibiotic prophylaxis developed a febrile episode compared with six out of six patients who did not receive antibiotic prophylaxis and developed a febrile episode. Patients with low MBL levels who responded less frequently to first line antibiotic therapy required more frequent administration of a second more advanced line of antibiotics, independently of receiving or not prophylaxis, and required prolonged hospitalization. In the univariate analysis low MBL associated with shorter OS. Our results suggest that patient with low MBL levels should receive antibiotic prophylaxis to reduce the number of febrile episodes and raise the issue of MBL replacement for these patients.

Epidemiology of bloodstream infections after myeloablative and non-myeloablative allogeneic hematopoietic stem cell transplantation: A single-center cohort study

BACKGROUND

Patients who undergo allogeneic hematopoietic stem cell transplantation (allo-HSCT) often develop bloodstream infections (BSI). We aimed to describe the etiologies and antibiotic resistance patterns of BSI after allo-HSCT, and, as knowledge about the impact of conditioning regimen is limited, we looked at the incidence, timing, risk factors, and mortality of BSI separately for myeloablative (MA)- and non-myeloablative (NMA)-conditioned patients.

METHODS

All 460 patients (207 MA- and 253 NMA-conditioned) who underwent their first allo-HSCT at our center from 2008 to 2013 were included in a historical cohort. BSI were registered from initiation of conditioning to day 360 after transplantation.

RESULTS

BSI occurred in 34% (95% confidence interval [CI]: 28%, 41%) of MA-conditioned patients and in 17% (95% CI: 12%, 22%) of NMA-conditioned patients. Of all isolates, 68% were gram-positive bacteria (GPB), 23% gram-negative bacteria (GNB), and 9% fungi. The GPB/GNB ratio declined from 2008 to 2014 (P for trend <.01). Of all GNB, 47% were multidrug resistant (MDR), but the proportion declined over the study period. In a multivariate Cox regression model, only acute graft-versus-host disease was associated with a higher hazard of first BSI (hazard ratio 2.50, 95% CI: 1.48, 4.21). Overall 30-day survival after a BSI was higher for MA-conditioned patients than for NMA-conditioned patients (89% vs 74%, P=.04).

CONCLUSION

MA-conditioned patients experience BSI more often than NMA-conditioned patients in the year after allo-HSCT. While BSI are increasingly caused by GNB, the rate of MDR GNB is declining.

Central Nervous System Infections

This chapter provides an overview of infectious syndromes, pathogens, and diagnostic testing modalities for central nervous system infections in the immunocompromised host.

Infections in Hematopoietic Cell Transplant Recipients: Results From the Organ Transplant Infection Project, a Multicenter, Prospective, Cohort Study

Background

Infection is a major cause of morbidity and mortality after allogeneic hematopoietic cell transplantation (HCT). Our object was to better define the epidemiology and outcomes of infections after HCT.

Methods

This was a prospective, multicenter cohort study of HCT recipients and conducted from 2006 to 2011.

The study included 4 US transplant centers and 444 HCT recipients. Data were prospectively collected for up to 30 months after HCT using a standardized data collection tool.

Results

The median age was 53 years, and median follow up was 413 (range, 5–980) days. The most common reason for HCT was hematologic malignancy (87%). The overall crude mortality was 52%. Death was due to underlying disease in 44% cases and infection in 21%. Bacteremia occurred in 231 (52%) cases and occurred early posttransplant (median day 48). Gram-negative bloodstream infections were less frequent than Gram-positive, but it was associated with higher mortality (45% vs 13%, P = .02). Clostridium difficile infection developed in 148 patients (33%) at a median of 27 days post-HCT. There were 53 invasive fungal infections (IFIs) among 48 patients (11%). The median time to IFI was 142 days. Of 155 patients with cytomegalovirus (CMV) infection, 4% had CMV organ involvement. Varicella zoster infection (VZV) occurred in 13 (4%) cases and was disseminated in 2. Infection with respiratory viruses was seen in 49 patients. Pneumocystis jirovecii pneumonia was rare (1%), and there were no documented cases of nocardiosis, toxoplasmosis, endemic mycoses, or mycobacterial infection. This study lacked standardized antifungal and antiviral prophylactic strategies.

Conclusions

Infection remains a significant cause of morbidity and mortality after HCT. Bacteremias and C difficile infection are frequent, particularly in the early posttransplant period. The rate of IFI is approximately 10%. Organ involvement with CMV is infrequent, as are serious infections with VZV and herpes simplex virus, likely reflecting improved prevention strategies.

The incidence, mortality and timing of Pneumocystis jiroveci pneumonia after hematopoietic cell transplantation: a CIBMTR analysis

Pneumocystis jiroveci pneumonia (PJP) is associated with high morbidity and mortality after hematopoietic stem cell transplantation (HSCT). Little is known about PJP infections after HSCT because of the rarity of disease given routine prophylaxis. We report the results of a Center for International Blood and Marrow Transplant Research study evaluating the incidence, timing, prophylaxis agents, risk factors and mortality of PJP after autologous (auto) and allogeneic (allo) HSCT. Between 1995 and 2005, 0.63% allo recipients and 0.28% auto recipients of first HSCT developed PJP. Cases occurred as early as 30 days to beyond a year after allo HSCT. A nested case cohort analysis with supplemental data (n=68 allo cases, n=111 allo controls) revealed that risk factors for PJP infection included lymphopenia and mismatch after HSCT. After allo or auto HSCT, overall survival was significantly poorer among cases vs controls (P=0.0004). After controlling for significant variables, the proportional hazards model revealed that PJP cases were 6.87 times more likely to die vs matched controls (P<0.0001). We conclude PJP infection is rare after HSCT but is associated with high mortality. Factors associated with GVHD and with poor immune reconstitution are among the risk factors for PJP and suggest that protracted prophylaxis for PJP in high-risk HSCT recipients may improve outcomes.

Hematopoietic stem-cell transplantation in the developing world: experience from a center in Western India

We describe our experience of first 50 consecutive hematopoietic stem-cell transplants (HSCT) done between 2007 and 2012 at the Apollo Hospital, Gandhinagar, 35 autologous HSCT and 15 allogeneic HSCT. Indications for autologous transplant were multiple myeloma, non-Hodgkin lymphoma, Hodgkin lymphoma, and acute myeloid leukemia, and indications for allogeneic transplants were thalassemia major, aplastic anaemia, chronic myeloid leukemia, and acute lymphoblastic and myeloid leukaemia. The median age of autologous and allogeneic patient's cohort was 50 years and 21 years, respectively. Median follow-up period for all patients was 39 months. Major early complications were infections, mucositis, acute graft versus host disease, and venoocclusive disease. All of our allogeneic and autologous transplant patients survived during the first month of transplant. Transplant related mortality (TRM) was 20% (N = 3) in our allogeneic and 3% (N = 1) in autologous patients. Causes of these deaths were disease relapse, sepsis, hemorrhagic complications, and GVHD. 46% of our autologous and 47% of our allogeneic patients are in complete remission phase after a median follow-up of 39 months. 34% of our autologous patients and 13% of our allogeneic patients had disease relapse. Overall survival rate in our autologous and allogeneic patients is 65.7% and 57.1%, respectively. Our results are comparable to many national and international published reports.

Invasive aspergillosis in children with acute leukemia at a resource-limited oncology center

BACKGROUND

Invasive aspergillosis (IA) is one of the most feared complications in patients with hematologic malignancies because it is associated with high morbidity and mortality, and significantly compromises antileukemia therapy.

OBJECTIVES

Analyze all patients with acute leukemia and IA of less than 18 years of age, diagnosed between January 1996 and December 2011.

MATERIALS AND METHODS

Cases were identified from the pediatric database for demographic details, disease characteristics, and IA-related data.

RESULTS

Among 356 patients with acute leukemia, 34 were identified to have proven/probable IA (5/29) with a relative incidence of 9% (28/310) and 13% (6/46) among acute lymphoblastic leukemia (ALL) and acute myeloid leukemia, respectively. Incidence of IA was significantly higher after 2004 especially among ALL patients; older patients with hyperglycemia and high-risk disease were more predisposed. None of the risk factors or type of antifungal treatment predicted mortality. The 120-day aspergillus-attributable mortality rate was 14.7%. IA led to a median of 17 days (2 to 44 d) of additional hospital stay and contributed to delay or reduction in planned chemotherapy in 30/34 patients.

CONCLUSIONS

An increasing trend in incidence of IA was observed during the latter half of study period. Early empiric therapy led to modest aspergillus-free survival. Clinical and financial implications of IA mandate review of institutional antifungal prophylaxis policy especially in selected ALL patients during induction.

Detection of bacteria and fungi in blood of patients with febrile neutropenia by real-time PCR with universal primers and probes

Febrile neutropenia is the main treatment-related cause of mortality in cancer patients. During June 2012 to April 2014, 97 blood culture samples were collected from patients receiving chemotherapy for hematological malignancy and cancer with febrile neutropenia episodes (FNEs). The samples were examined for the presence of bacteria and fungi using real-time PCR amplification and sequencing of 16S and 18S rRNA genes. Bacteria were identified in 20 of 97 samples (20.6%) by the real-time PCR assay and in 10 of 97 (10.3%) samples by blood culture. In 6 blood culture-positive samples, the real-time PCR assay detected the same type of bacteria. No fungi were detected by the real-time PCR assay or blood culture. During antibiotic therapy, all samples were negative by blood culture, but the real-time PCR assay yielded a positive result in 2 cases of 2 (100%). The bacterial DNA copy number was not well correlated with the serum C-reactive protein titer of patients with FNEs. We conclude that a real-time PCR assay could provide better detection of causative microbes' in a shorter time, and with a smaller blood sample than blood culture. Using a real-time PCR assay in combination with blood culture could improve microbiological documentation of FNEs.

Utility of routine surveillance blood cultures in asymptomatic allogeneic hematopoietic stem cell transplant recipients with indwelling central venous catheters at a comprehensive cancer center

BACKGROUND

Many transplant centers obtain surveillance blood cultures (SBCs) from asymptomatic allogeneic hematopoietic stem cell transplant (allo-HCT) recipients with central venous catheters for early detection of potential blood stream infections. The aim of this study was to determine the utility of this practice.

METHODS

We conducted a retrospective study of all patients who underwent allo-HCT to determine the frequency, clinical significance, and costs associated with SBCs.

RESULTS

From 776 patients, 6,801 SBCs were obtained (median, 9 per patient). Most (96.89%) were negative. Of the 211 positive SBCs, 171 (81%) had minimal clinical significance. The remaining 40 positive cultures (19%) were considered potentially significant. The frequency of potentially significant SBCs was 5.1% for the entire cohort and 0.59% of all SBCs drawn.

CONCLUSION

All potentially significant cultures and some that were deemed to have minimal significance led to medical intervention, some of which were probably unnecessary. No adverse outcomes occurred in patients with positive SBCs for the first 30 days following the positive result, regardless of the pathogen isolated or the quantitative colony count. The frequency of clinically significant positive SBCs in asymptomatic adult allo-HCT recipients is very low. Routine use of this practice leads to some unnecessary medical interventions and added costs.

Utility of surveillance blood cultures in patients undergoing hematopoietic stem cell transplantation

Background

Surveillance blood cultures are often obtained in hematopoietic stem cell transplant (HSCT) patients for detection of bloodstream infection. The major aims of this retrospective cohort study were to determine the utility of the practice of obtaining surveillance blood cultures from asymptomatic patients during the first 100 post-transplant days and to determine if obtaining more than one positive blood culture helps in the diagnosis of bloodstream infection.

Methods

We conducted a 17-month retrospective analysis of all blood cultures obtained for patients admitted to the hospital for HSCT from January 2010 to June 2011. Each patient’s clinical course, vital signs, diagnostic testing, treatment, and response to treatment were reviewed. The association between number of positive blood cultures and the final diagnosis was analyzed.

Results

Blood culture results for 205 patients were reviewed. Cultures obtained when symptoms of infection were present (clinical cultures) accounted for 1,033 culture sets, whereas 2,474 culture sets were classified as surveillance cultures (no symptoms of infection were present). The total number of positive blood cultures was 185 sets (5.3% of cultures obtained) and accounted for 84 positive culture episodes. Incidence of infection in autologous, related allogeneic and unrelated allogeneic transplants was 8.3%, 20.0%, and 28.6% respectively. Coagulase-negative staphylococci were the most common organisms isolated. Based on our application of predefined criteria there were 29 infections and 55 episodes of positive blood cultures that were not infections. None of the patients who developed infection were diagnosed by surveillance blood cultures. None of the uninfected patients with positive blood cultures showed any clinical changes after receiving antibiotics. There was a significant difference between the incidence of BSI in the first and second 50-day periods post-HSCT. There was no association between the number of positive blood cultures and the final diagnosis.

Conclusion

Surveillance blood cultures in patients who have undergone HSCT do not identify bloodstream infections. The number of positive blood cultures was not helpful in determining which patients had infection. Patients are at higher risk of infection in the first 50 days post-transplant period.

The predictive value for pulmonary infection by area over the neutrophil curve (D-index) in patients who underwent reduced intensity hematopoietic stem cell transplantation

We evaluated the predictive value of the D-index for pulmonary infection in the early phase of reduced intensity stem cell transplantation (RIST). Out of 68 patients, ten patients developed a pulmonary infection within 100 days after RIST. Both the D-index and the cD-index were higher in the patients with pulmonary infection than in the control group (P = 0.009, P = 0.042, respectively). The best sensitivity and specificity, calculated with receiver operating characteristic curves, showed that the D-index was superior to the duration of neutropenia in predicting pulmonary infection. We also evaluated the utility of a cumulative D-index until 21 days after RIST (D21-index). The D21-index was higher in the patients with pulmonary infection (P = 0.047). The cutoff value of the D21-index was lower than that of the D-index (8650 vs. 11000) with comparable sensitivity and specificity. Our results demonstrate that the D21-index, as well as the D-index, are useful tools for the prediction of pulmonary infection in RIST.

High resistance of Pseudomonas aeruginosa to paromomycin, an agent used for selective bowel decontamination (SBD)

BACKGROUND

Paromomycin is used for selective bowel decontamination (SBD) in patients undergoing bone marrow transplantation in many hospitals, but there are no published resistance data for this compound in the recent medical literature. The aim of this study was to investigate the in vitro activity of paromomycin against the common intestinal bacteria E. coli and P. aeruginosa.

METHODS

94 E. coli isolates and 77 P. aeruginosa isolates derived from clinical specimens were tested by broth microdilution against paromomycin and amikacin, respectively, following the CLSI recommendations for testing amikacin.

RESULTS

86 of 94 E. coli isolates (91%) and 71 of 77 P. aeruginosa isolates (92%) showed in vitro susceptibility to amikacin (MIC90 for both compounds: 16 µg/ml, range: 1-32 µg/ml for E. coli and 1->128 µg/ml for P. aeruginosa). Paromomycin was active against 83/94 E. coli isolates (88%; MIC90: 32 µg/ml, range: 2->128 µg/ml), but showed poor in vitro activity against P. aeruginosa (3/77 isolates susceptible [4%]; MIC90: >128 µg/ml, range: 2->128 µg/ml).

CONCLUSION

If SBD with inclusion of an aminoglycoside antibiotic is applied, paromomycin should not be used unless local resistance data provide evidence of a sufficient in vitro activity of this compound against P. aeruginosa.

Routine surveillance for bloodstream infections in a pediatric hematopoietic stem cell transplant cohort: Do patients benefit?

BACKGROUND

Hematopoietic stem cell transplant (HSCT) recipients are at a high risk for late bloodstream infection (BSI). Controversy exists regarding the benefit of surveillance blood cultures in this immunosuppressed population. Despite the common use of this practice, the practical value is not well established in non-neutropenic children following HSCT.

METHODS

At the IWK Health Centre (Halifax, Nova Scotia), weekly surveillance blood cultures from central lines are drawn from children following HSCT until the line is removed. A retrospective chart review was performed to determine the utility and cost of this practice. Eligible participants were non-neutropenic HSCT recipients with central venous access lines. The cost of laboratory investigations, nursing time, hospital stay and interventions for positive surveillance cultures was calculated.

RESULTS

Forty-three HSCTs were performed in 41 children. Donors were allogenic in 33 cases (77%) and autologous in 10 cases (23%). There were 316 patient contacts for surveillance cultures (mean seven per patient) and 577 central line lumens sampled. Three of 43 patients (7%) had clinically significant positive surveillance blood cultures. Bacteria isolated were Klebsiella pneumoniae (n=2) and Corynebacterium jeikeium (n=1). All follow-up cultures before initiation of antimicrobial therapy were sterile. All three patients were admitted for antimicrobial therapy if they were not already hospitalized and/or had an uncomplicated course. The estimated total cost of BSI surveillance and management of asymptomatic infection over six years was $27,989.

CONCLUSION

The present study suggests that BSI surveillance in children following HSCT engraftment has a very low yield and significant cost. It is unclear whether it contributes to improved patient outcomes.

Prophylactic antibiotics for the prevention of neutropenic fever in patients undergoing autologous stem-cell transplantation: results of a single institution, randomized phase 2 trial

One hundred and fifty-seven patients undergoing high-dose chemotherapy (HDT) and autologous stem-cell transplantation (ASCT) for hematopoietic malignancies and solid tumors were randomly assigned to receive (Group A) or not (Group B) prophylaxis with ciprofloxacin, orally, and vancomycin, intravenously. Prophylactic antibiotics were given from day 0 until resolution of neutropenia or the appearance of a febrile event. Furthermore, patients in both groups received once a day fluconazole, orally. The primary end-point of our study was the incidence of neutropenic febrile episodes attributed to infection. One hundred and twelve (71.3%) patients developed neutropenic fever, 50 (56.2%) in Group A and 62 (91.2%) in Group B (P < 0.001) with the majority (82%) of patients developing fever of unknown origin. Patients on prophylactic antibiotics had a significantly lower rate of bacteremias (5.6%) than did those randomized to no prophylaxis (29.4%) (P = 0.005) and, when developing neutropenic fever, they had a lower probability of response to first-line empirical antibiotics (P = 0.025). Prophylactic administration of ciprofloxacin and vancomycin reduced the incidence of neutropenic fever in patients receiving HDT with ASCT, however, without affecting the total interval of hospitalization, time to engraftment, or all-cause mortality. Therefore, our results do not support the use of antibiotic prophylaxis for patients undergoing HDT and ASCT.

Aminoglycoside-free interventional antibiotic management in patients undergoing haemopoietic stem cell transplantation

The position of aminoglycosides within interventional antibiosis in the early phase after stem cell transplantation has not been fully clarified so far although their use can induce serious renal impairment. To investigate this question early-infection data from 152 patients undergoing 195 allogeneic and autologous stem cell transplantations were investigated. Prophylaxis and treatment of infections followed international standards; however, aminoglycosides were omitted to avoid additional risks such as ototoxicity and nephrotoxicity and increased selection of resistant pathogens. Costs were another aspect.

The overall-incidence of infections was 78% (152/195) and 67 patients showed more than one episode of infection. Fever of unknown origin and bacteriaemia/septicaemia dominated the spectrum of infections. The overall-response to interventional regimen consisting of β-lactam or carbapenem plus glycopeptides was 48%. Aminoglycosides were given in three patients in the late course of disease. Overall mortality was 15/195 (7.7%) and clearly related to infection in nine cases mostly due to mould infection. A comparison with previous published literature showed no hint for inferiority of ‘aminoglycoside-free’ antibiotic management in stem cell transplant patients. In conclusion, the present analysis supports the policy to omit aminoglycosides in the therapy of early infections in patients undergoing stem cell transplantation to avoid additional toxicity.

Fibrinogen and antithrombin in hematological patients with neutropenic fever

The value of plasma fibrinogen and antithrombin as predictors of severe sepsis was investigated in 69 adult hematological patients, who had altogether 93 periods of neutropenic fever. Patients had either acute myeloid leukemia or had received a high dose of chemotherapy supported by autologous stem cell transplantation. In febrile periods with severe sepsis, the median fibrinogen concentration at the start of the fever was significantly higher (5.0 g/L) than that without severe sepsis (4.5 g/L) (p=0.009). Normal plasma fibrinogen could rule out a group of patients with severe sepsis at the beginning of the fever. The antithrombin activity decreased, both in fever periods with severe sepsis and in those without. The decrease in antithrombin activity was found to be greater in fever periods characterized by severe sepsis. In conclusion, elevated plasma fibrinogen and constantly decreasing antithrombin were shown to be linked to the development of severe sepsis.

Early infections in patients undergoing high-dose treatment with stem cell support: a comparison of patients with non-Hodgkin lymphoma and multiple myeloma

BACKGROUND

Infections are life-threatening complications in patients undergoing high-dose chemotherapy with stem cell support (HDT). Knowledge of the infectious pathogens is essential to make a safe outpatient setting.

METHODS

We conducted a retrospective study of 208 patients treated with HDT. The population included non-Hodgkin lymphoma (NHL) and multiple myeloma (MM) patients. No patients received prophylactic antibacterial treatment.

RESULTS

Pathogens were isolated from 44% of all patients. MM patients more frequently had multiple pathogens in blood cultures (38% versus 25%). Transplantation related mortality was similar between the groups.

CONCLUSION

The frequency of isolated pathogens, positive blood cultures, and the diversity of pathogens were higher in MM patients as compared to NHL patients. However, this did not translate into higher transplantation-related mortality, probably because broad-spectrum antibiotic treatment could be initiated immediately. A safe outpatient setting with prophylactic antibiotic treatment is dependent on continuous collection and registration of microbiological findings.

Blood stream infection (BSI) and acute GVHD after hematopoietic SCT (HSCT) are associated

BSI and acute GVHD (aGVHD) are serious complications of HSCT. We hypothesized that the two events were not independent of one another. We studied (1) associations between BSI and aGVHD; (2) the impact of BSI and/or aGVHD on death within 100 days after HSCT, employing a retrospective cohort analysis. Risk factor analysis was performed using multivariable Cox proportional hazards analyses. Of 211 subjects undergoing allogeneic HSCT from 1/00–12/05 (58% of whom underwent reduced intensity transplantation), 82 (39%) developed BSI. In 49 patients (23%), grades (gr) 2–4 aGVHD occurred. Early BSI was independently associated with an increased occurrence of subsequent aGVHD gr 2–4. Cytomegalovirus seropositivity was independently associated with decreased occurrence of aGVHD. Acute GVHD gr 2–4 independently predicted subsequent first BSI. Both BSI and aGVHD gr 2–4 were significant independent predictors of death within 100 days after HSCT. There is a strong, independent association between BSI and aGVHD. Potential explanations include the elaboration of cytokines during BSI favoring the development of aGVHD and/or the immunosuppressive treatment of aGVHD favoring the development of BSI. Future studies should be directed at mechanistic investigations of this association.

Increasing incidence of invasive aspergillosis in pediatric hematology oncology patients over the last decade: a retrospective single centre study

There is scanty information about invasive aspergillosis (IA) in the pediatric population. A review of IA at Hospital Infantil Universitario Niño Jesús between 1996 and 2006 was undertaken to analyze incidence, risk factors, and treatment response. Twenty patients were diagnosed with probable or proven IA during the study period, with a cumulative incidence of 1.96%. Incidence was higher in hematopoietic stem cell transplantation (HSCT) recipients: 2.26% (3.5% in allogeneic HSCT and 1.2% in autologous HSCT). A significative increase in IA incidence was observed along the study period (P=0.013), although this increase did not reach signification if only proven cases were compared (P=0.058). Most patients presented multiple risk factors for IA (87% more than 1, and 47% more than 3). The most frequently described risk factor was chemotherapy (90%), after by long-term neutropenia (90%), and corticotherapy (75%). Main locations of the infection were pulmonary (8 patients), cutaneous (3 patients) and intestinal (3 patients). Six patients presented disseminated IA. Initial response to treatment was 55%, although 3 of these cases had a subsequent episode. Global antifungal response, at the end of the follow-up, was 45%. IA-related mortality was 55%. Global mortality was 90%. Only 2 patients (isolated cutaneous IA cases) survived. Seven patients died due to their underlying malignant disease without active fungal disease. Incidence of IA in oncology children is increasing, and in adults. In our experience, IA is a marker of poor outcome even for patients who initially respond to antifungal treatment.

Characteristics of and risk factors for pneumonia in patients with hematological malignancies developing fever after autologous blood stem cell transplantation

We analyzed the incidence, etiology, risk factors and outcomes of 49 episodes of pneumonia that developed in 326 adult patients undergoing autologous stem-cell transplantation (ASCT) from January 1990 to December 2005. The median time for the onset of pneumonia after transplantation was 11 days (range 0-148). Empirical antibiotic therapy in patients with pneumonia consisted of piperacillin-tazobactam (20 cases, 49%), third-generation cephalosporin (11 cases, 27%) and carbapenem (8 cases, 19%). Multivariate analysis showed that a higher risk of pneumonia could be predicted for patients with myeloma (P = 0.006) and for patients with an absolute neutrophil count <0.5 x 10(9)/L >7 days (P = 0.008). Cumulative incidence of transplant-related mortality at 6 months was 51% versus 8% for patients with or without pneumonia, respectively (P = 0.001). Pneumonia after ASCT is a severe complication more commonly observed in patients with myeloma and with prolonged duration of neutropenia.

Lung macrophages serve as obligatory intermediate between blood monocytes and alveolar macrophages

Alveolar macrophages are a unique type of mononuclear phagocytes that populate the external surface of the lung cavity. Early studies have suggested that alveolar macrophages originate from tissue-resident, local precursors, whereas others reported their derivation from blood-borne cells. However, the role of circulating monocytes as precursors of alveolar macrophages was never directly tested. In this study, we show through the combined use of conditional cell ablation and adoptive cell transfer that alveolar macrophages originate in vivo from blood monocytes. Interestingly, this process requires an obligate intermediate stage, the differentiation of blood monocytes into parenchymal lung macrophages, which subsequently migrate into the alveolar space. We also provide direct evidence for the ability of both lung and alveolar macrophages to proliferate.

Invasive aspergillosis: epidemiology, diagnosis and management in immunocompromised patients

Morbidity and mortality caused by invasive Aspergillus infections are increasing. This is because of the higher number of patients with malignancies treated with intensive immunosuppressive therapy regimens as well as their improved survival from formerly fatal bacterial infections, and the rising number of patients undergoing allogeneic haematopoietic stem cell or organ transplantation. Early initiation of effective systemic antifungal treatment is essential for a successful clinical outcome in these patients; however, clinical clues for diagnosis are sparse and early microbiological proof of invasive aspergillosis (IA) is rare. Clinical diagnosis is based on pulmonary CT scan findings and non-culture based diagnostic techniques such as galactomannan or DNA detection in blood or bronchoalveolar lavage samples. Most promising outcomes can be expected in patients at high risk for aspergillosis in whom antifungal treatment has been started pre-emptively, backed up by laboratory and imaging findings. The gold standard of systemic antifungal treatment is voriconazole, which has been proven to be significantly superior to conventional amphotericin B and has led to a profound improvement of survival rates in patients with cerebral aspergillosis. Liposomal amphotericin B at standard dosages appears to be a suitable alternative for primary treatment, while caspofungin, amphotericin B lipid complex or posaconazole have shown partial or complete response in patients who had been refractory to or intolerant of primary antifungal therapy. Combination therapy with two antifungal compounds may be a promising future strategy for first-line treatment. Lung resection helps to prevent fatal haemorrhage in single patients with pulmonary lesions located in close proximity to larger blood vessels, but is primarily considered for reducing the risk of relapse during subsequent periods of severe immunosuppression. Strict reverse isolation appears to reduce the incidence of aspergillosis in allogeneic stem cell transplant recipients and patients with acute myeloid leukaemia undergoing aggressive anticancer therapy. Well designed, prospective randomised studies on infection control measures effective to prevent aspergillosis are lacking. Prophylactic systemic antifungal treatment with posaconazole significantly improves survival and reduces IA in acute myeloid leukaemia patients and reduces aspergillosis incidence rates in patients with intermediate-to-severe graft-versus-host reaction emerging after allogeneic haematopoietic stem cell transplantation. Voriconazole prophylaxis may be suitable for prevention of IA as well; however, the results of large clinical trials are still awaited.

Hygienic safety of reusable tap water filters (Germlyser) with an operating time of 4 or 8 weeks in a haematological oncology transplantation unit

Background

Microbial safe tap water is crucial for the safety of immunosuppressed patients.

Methods

To evaluate the suitability of new, reusable point-of-use filters (Germlyser^®, Aquafree GmbH, Hamburg, Germany), three variations of a reusable filter with the same filter principle but with different outlets (with and without silver) and inner surface coating of the filter encasements (with and without nano-crystalline silver) were tested. The filter efficacy was monitored over 1, 4 and 8 weeks operating time in a haematological oncology transplantation unit equipped with 18 water outlets (12 taps, 6 showers).

Results

The filtered water fulfilled the requirements of absence of pathogens over time. From 348 samples, 8 samples (2.3%) exceeded 100 cfu/ml (no sample ≥ 500 cfu/ml). As no reprocessed filter exhibited 100% filter efficacy in the final quality control after each reprocessing, these contaminations could be explained by retrograde contamination during use.

Conclusion

As a consequence of the study, the manufacturer recommends changing filters after 4 weeks in high risk areas and after 8 weeks in moderate infectious risk areas, together with routine weekly alcohol-based surface disinfection and additionally in case of visible contamination. The filter efficacy of the 3 filters types did not differ significantly regarding total bacterial counts. Manual reprocessing proved to be insufficient. Using a validated reprocessing in a washer/disinfector with alkaline, acid treatment and thermic disinfection, the filters were effectively reprocessable and now provide tap water meeting the German drinking water regulations as well as the WHO guidelines, including absence of pathogens.

A decision analysis: the dental management of patients prior to hematology cytotoxic therapy or hematopoietic stem cell transplantation

There is a controversy regarding whether dental treatment before chemotherapy protocols, including hematopoietic stem cell transplantation (HSCT), is helpful to prevent infections during the consequent immunosuppression. The aim of this study was to develop a decision analysis framework that would test the effect of dental treatment prior to chemotherapy on the survival of the patient. A decision tree was created to compare the clinical outcomes of two treatment alternatives for a base-case patient receiving cytotoxics or undergoing HSCT. The variables used to build the model were "systemic infection", "unmet dental needs", "dental needs". The outcomes evaluate to compare the two strategies was "survival". We performed MEDLINE and PubMed searches of English-language literature according to a list of related terms. The decision analysis model selected dental treatment prior to chemotherapy as the preferred strategy for the base case analysis. The results of this study suggest that dental treatment prior to chemotherapy is the preferred treatment strategy. Using our base case data, 1.8 of every 1000 hemato-oncologic patients or HSCT patients will die compared to the non-treatment prior to chemotherapy strategy.

Evaluation of pulmonary infiltrates in patients after stem cell transplantation

Hematopoietic stem cell transplantation is potentially curative therapy that has become the standard of care for many hematologic malignancies. Pulmonary complications occur in about 50% of stem cell transplant recipients and no other organ dysfunction has a higher mortality. Unfortunately the diagnosis of these infiltrates is hampered by the poor yield from routine studies and this patient population is rarely able to tolerate more risky procedures that will obtain tissue for microscopy and culture. A bronchoalveolar lavage (BAL) is usually insufficient to make a diagnosis of invasive fungal, significant bacterial, or pathogenic viral infections in patients that will still benefit from a change in therapy. In this review we discuss the infectious etiologies of pulmonary infiltrates post hematopoietic stem cell transplant, the non-infectious causes of infiltrates such as diffuse alveolar hemorrhage, engraftment syndrome, and idiopathic pneumonia syndrome, and the yield of newer diagnostic procedures ranging from peripheral blood galactomannan to cytomegalovirus antigenemia, and report on new technologies that promise more accurate and timely diagnoses of these infiltrates.

Establishment of a pediatric HSCT program in a public hospital in Chile

BACKGROUND

In Chile, survival estimates for pediatric patients with cancer are comparable to those in the United States and Western Europe. Approximately 80% of these patients are treated at government-supported centers, and an estimated 65% are cured. We reasoned that cure rates could be further improved if transplantation with hematopoietic stem cells were available for patients with chemotherapy-resistant malignancy.

PATIENTS AND METHODS

Physicians and nurses were selected to be trained in international centers, and a transplantation unit was developed at Luis Calvo Mackenna Hospital in Santiago. Between October 1999 and December 2003, 59 patients received transplants. Of these, 42 were from HLA-matched family members and 11 were autologous.

RESULTS

The 3-year event-free survival estimate was 72 +/- 10% overall, and it was 81 +/- 10% for the subgroup treated with matched related transplants. Peritransplant mortality was 6.6%. The average cost for an allogeneic transplant in our unit was 50,000 US dollars.

CONCLUSIONS

We are encouraged by this experience as well as by the overall survival rates and hope to expand the program. Our goal is to extend treatment to all children in the country for whom HSCT is indicated, including those who do not have HLA-identical family donors.

The modification of high-dose therapy shortens the duration of neutropaenia by delay of leucocyte nadir

Infections during neutropaenia contribute still significantly to mortality and morbidity after high-dose therapy and autologous stem cell transplantation. Further acceleration of haemopoietic recovery seems impossible for biological reasons. Another approach to shorten neutropaenia could be to remove drugs from high-dose therapy protocols with strong contribution to immunosuppression and neutropaenia and unproven antineoplastic activity. In this retrospective matched-pair analysis, conventional busulphan/cyclophosphamide (Bu/Cy) high-dose therapy was compared to single-agent busulphan conditioning before autologous stem cell transplantation. This modification led to a significant shorter neutropaenic interval by protraction of cell decrease and to a significant mitigation of neutropaenia. After single-agent busulphan conditioning, leucocytes dropped below 1/nl at median 1.5 days later when compared to the patients from the busulphanBu/Cy control group (P=0.001). In a significant percentage of patients (n=6, 60%) leucocytes did not fall below 0.5 cells/nl at any time. In contrast, all patients from the Bu/Cy control group experienced deep neutropaenia (P=0.004). Thrombocytopaenia and requirement for transfusions of platelets or red cells were not influenced. Antineoplastic activity seemed to be preserved as determined by survival analysis. In conclusion, modification of high-dose regimen with the intention to shorten neutropaenia with preserved antitumour activity could be an approach to reduce infection-related morbidity and mortality and to consider economic necessities.

Infections in children undergoing allogeneic bone marrow transplantation in India

We studied the clinical profile of infections among 221 pediatric patients who underwent 230 allogeneic transplants between 1986 and June 2004. All patients developed febrile neutropenia. There were 283 documented infections, which included bacterial (36.9%), viral (45.7%), fungal (11.1%) and other infections (6.3%) including tuberculosis. Bacterial and fungal infections were more common in the first 30 days following BMT, while viral infections were more common >30 days after BMT. Bacterial pathogens were predominantly gram-negative organisms (72.7%), when compared with gram-positive organisms (27.3%). Common gram-negative organisms included NFGNB, Pseudomonas, Escherichia coli and Klebsiella while coagulase negative Staphylococci was the main gram-positive organism. Bacteremia (61.2%) was the main source positive cultures and was mainly because of gram-negative organisms (81%), predominantly NFGNB and Pseudomonas. Exactly 103/221(43.7%) transplants had 128 documented viral infections commonly because of Cytomegalovirus, Herpes group of viruses and transfusion related hepatitis. Thirty of 221 (13.5%) of transplants had 30 documented fungal infections with the majority being because of aspergillus (90%). Tuberculosis was seen in 1.7% of transplants while catheter infections were seen in 21 patients (9.1%). Infection related mortality was seen in 12% predominantly because of CMV or fungal infections. A sub group analysis (pre-1998 vs. post-1998) revealed higher incidences of gram-negative infections, bacteremia and bacterial infection related mortality in the pre-1998 era when compared with the recent times. The profile and mortality of infections in this series from India is not significantly different from reports from the West.

Surveillance of nosocomial infections in paediatric recipients of bone marrow or peripheral blood stem cell transplantation during neutropenia, compared with adult recipients

The aim of this prospective study was to analyse the incidence of nosocomial infections (NIs) during neutropenia after haematopoietic stem cell transplantation (HSCT) in paediatric and adult patients. Diagnosis of NI followed the modified surveillance protocol of the German National Reference Centre for Surveillance of NIs. During the 24-month study period, 38 and 39 transplantations were performed in paediatric and adult patients, respectively. Eighty percent and 92% of the paediatric and adult patients, respectively, underwent allogenic HSCT. In total, 1156 neutropenic days were documented. The incidence of NI during neutropenia in all recorded cases was 38.9 NI per 1000 days, without significant difference between the groups. No difference was found in the incidence rates of pneumonia, while there was a trend towards a higher incidence of bloodstream infection in adult patients. Significantly more episodes of fever of unknown origin were found in paediatric than adult patients. Pathogens were isolated in 19 of 45 cases of NI. Of the clinically documented infections, Gram-positive organisms were isolated in 79%, Gram-negative organisms were isolated in 16% and fungi were isolated in 5%. Surveillance of NI is an effective instrument to control the quality of health care. It should focus on device-associated infections or specific high-risk targets such as nosocomial pneumonia.

Prophylaxis of early bacterial infections after autologous peripheral blood stem cell transplantation (PBSCT): a matched-pair study comparing oral fluoroquinolones and intravenous piperacillin-tazobactam

The safety and efficacy of early bacterial prophylaxis with piperacillin-tazobactam were prospectively evaluated in 51 autologous peripheral blood stem cell transplantation (PBSCT) recipients. The results were compared with those obtained in 51 control patients receiving oral fluoroquinolones in a retrospective matched-pair control study. Overall, 76% of the study group and 98% of the control group developed at least one febrile episode during neutropenia (P=0.002). Time from neutropenia to the first febrile episode (FFE) was significantly longer in the study group than in the control group (P=0.04). Once a febrile episode appeared, the duration of fever was significantly longer in cases than in controls (median of 5 and 2 days respectively, P<0.001), and led to a more frequent use of empirical amphotericin B (AmB), not statistically significant (P=0.13). However, the total time of antibiotic administration was significantly greater in the control than in the study group (P=0.05). The duration of AmB treatment shows a trend toward a longer duration in the control than in study group (P=0.2). Overall, 86% of the Gram-positive bacteremia and 85% of the Gram-negative bacteria were susceptible to the tested antibiotics. Our study suggests that a subgroup of patients could benefit from prophylaxis with piperacillin-tazobactam without increasing toxicity or bacterial resistance.

Fluoroquinolone resistance in hematopoietic stem cell transplant recipients with infectious complications

The infectious complications are an important cause of morbidity and mortality in hematopoietic stem cell transplant (HSCT) recipients. Our retrospective study has the objective to evaluate the incidence, clinical and bacteriologic features of documented infections in these patients. The frequency of infectious complications was analysed in 42 patients with hematologic malignancies who received HSCT from January to December 2002 at Pisa General Hospital. Thirty-three patients underwent autologous HSCT and 9 received allogeneic HSCT. All patients received acyclovir, fluconazole and fluoroquinolones as prophylactic regimen. A total of 38 infectious episodes were recognized in 22 patients during the early post-HSCT period (N=27) and in the late post-HSCT period (N=11). Infectious complications rate correlated positively with the deepness and length of neutropenia in the early period. There were 21 episodes of sepsis (the majority by coagulase negative staphylococci), 2 pneumonias and 1 vertebral osteomyelitis. All staphylococcus strains were, in vitro, resistant to oxacillin and ciprofloxacin and 8 out of 15 gram negative rods were resistant to ciprofloxacin. Most of the infectious complications were cured with appropriated antimicrobial therapy and/or with engraftment and, in 4 cases, with central catheter removal. One patient developed a positive CMV antigenemia; a pre-core mutant form of HBV reactivation was diagnosed in another patient. No cases of invasive fungal infections were recognised. Five patients died but only one from infection (septic shock). Pneumonia was a coexisting cause of death in 2 patient in the late period. We can conclude that most of infectious complications, that occurred in the early period post-HSCT were due to coagulase negative staphylococci and gram negative rods resistant to ciprofloxacin. For this reason, the usefulness of fluoroquinolone prophylaxis in HSCT recipients should be reevaluated.

Early bacteremia in pediatric hematopoietic stem cell transplant patients on oral antibiotic prophylaxis

BACKGROUND

Bacteremia occurs during hematopoietic stem cell transplant (HSCT) in 20%-25% of patients and the use of gut decontamination (GD) to decrease this risk is controversial. Our purpose was to determine the incidence of bacteremia and antimicrobial resistance post-HSCT in pediatric patients receiving GD, and to identify risk factors associated with infection.

PROCEDURES

This was a retrospective cohort study of 182 pediatric patients undergoing first HSCT for malignant disease at The Children's Hospital of Philadelphia from January, 1999 to December, 2002. We examined the impact of age, sex, race, diagnosis, disease status, conditioning regimen, recent bacteremia, stem cell source, donor, graft versus host disease prophylaxis agents, and mucositis severity using Cox proportional hazard models. GD consisted of amoxicillin (azithromycin, if penicillin allergic) and oral gentamicin. Outcome was first episode of bacteremia prior to absolute neutrophil count (ANC) 500/mm(3). Antibiotic susceptibilities were performed on all isolates.

RESULTS

Seventy-four patients (41%) developed bacteremia. The majority were Gram-positive cocci, with Staphylococcal (50%) and Streptococcal species (28%) the most common. Gram-negative organisms were identified in 22% with Pseudomonas (5.7%) and Klebsiella species (3.4%) the most common. Of the Streptococcal infections, 72% were resistant to ampicillin; only 25% of the Gram-negative bacteria were resistant to gentamicin. Race was the only factor associated with early bacteremia (hazard ratio 2.3 for non-Caucasian, non-African-American patients, CI 1.3-4.3, P = 0.007).

CONCLUSIONS

Early bacteremia is common after HSCT, despite the use of GD. Resistant Gram-positive organisms predominate, consistent with recent trends in immunocompromised patients. Although used in practice, there is no clear evidence for the efficacy of GD and this study provides the basis upon which to develop a randomized clinical trial evaluating the current GD regimen with placebo.

Antimicrobial prophylaxis in allogeneic bone marrow transplantation. Guidelines of the Infectious Diseases Working Party (AGIHO) of the German Society of Haematology and Oncology

Patients undergoing allogeneic stem cell transplantation are at high risk for infection with a variety of pathogens during different phases of the procedure. Bacteria and fungi predominate the first phase until engraftment. During the second phase, from engraftment to about day 100, major infectious problems are caused by fungi and cytomegalovirus. Both pathogens remain important under continued immunosuppression, however, in the late post-transplantation period infections with encapsulated bacteria may become a problem. In this review the Infectious Diseases Working Party of the DGHO gives recommendations for prophylaxis of infections under allogeneic stem cell transplantation with drugs and other measures. The aim of the group was to do this on an evidence-based-medicine rating, if possible.

Transferrin: structure, function and potential therapeutic actions

There are many proteins that can multi-task. Transferrin, widely known as an iron-binding protein, is one such example of a multi-tasking protein. In this review, the multiple biological actions of transferrin, including its growth and cytoprotective activities, are discussed with the view of highlighting the potential therapeutic applications of this protein.

Value of surveillance blood culture for early diagnosis of occult bacteremia in patients on corticosteroid therapy following allogeneic hematopoietic stem cell transplantation

Bloodstream infection (BSI) is a significant complication following allogeneic hematopoietic stem cell transplantation (allo-SCT). Corticosteroids mask inflammatory responses, delaying the initiation of antibiotics. We reviewed medical records of 69 allo-SCT patients who had been on >0.5 mg/kg prednisolone to investigate the efficacy of weekly surveillance blood cultures. A total of 36 patients (52%) had positive cultures, 25 definitive BSI and 11 probable BSI. Pathogens in definitive BSI were Staphylococcus epidermidis (n=7), S. aureus (n=4), Entrococcus faecalis (n=3), Pseudomonas aeruginosa (n=5), Acenitobacter lwoffii (n=4), and others (n=10). The median interval from the initiation of corticosteroids to the first positive cultures was 24 days (range, 1-70). At the first positive cultures, 15 patients with definitive BSI were afebrile. Four of them remained afebrile throughout the period of positive surveillance cultures. Patients with afebrile BSI tended to be older (P=0.063), and had in-dwelling central venous catheters less frequently than febrile patients (P<0.0001). Bloodstream pathogens were directly responsible for death in two patients with afebrile BSI. This study demonstrates that cortisosteroid frequently masks inflammatory reactions in allo-SCT recipients given conrticosteroids, and that surveillance blood culture is only diagnostic clue for 'occult' BSI.