Occurrence Of Bacteremia Research Articles

Naturally Occurring IgG Antibodies Provide Innate Protection against Vibrio cholerae Bacteremia by Recognition of the Outer Membrane Protein U

Cholera epidemics are caused by Vibrio cholerae serogroups O1 and O139, whereas strains collectively known as non-O1/non-O139 V. cholerae are found in cases of extraintestinal infections and bacteremia. The mechanisms and factors influencing the occurrence of bacteremia and survival of V. cholerae in normal human serum have remained unclear. We found that naturally occurring IgG recognizing V. cholerae outer membrane protein U (OmpU) mediates a serum-killing effect in a complement C1q-dependent manner. Moreover, outer membrane vesicles (OMVs) containing OmpU caused enhanced survival of highly serum-sensitive classical V. cholerae in a dose-dependent manner. OMVs from wild-type and ompU mutant V. cholerae thereby provided a novel means to verify by extracellular transcomplementation the involvement of OmpU. Our data conclusively indicate that loss, or reduced expression, of OmpU imparts resistance to V. cholerae towards serum killing. We propose that the difference in OmpU protein levels is a plausible reason for differences in serum resistance and the ability to cause bacteremia observed among V. cholerae biotypes. Our findings provide a new perspective on how naturally occurring antibodies, perhaps induced by members of the microbiome, may play a role in the recognition of pathogens and the provocation of innate immune defense against bacteremia.

Bacteriologic Study in Burn Patients Admitted to Burn Ward of Sina Hospital of Tabriz During 2012 - 2013: A Cross-Sectional Study

Background: One of the important causes of mortality and morbidity in burn wards is infection. There are several reasons which make burn patients disposed to infection. Objectives: The current study aimed to investigate the role of different factors that affect bacteremia occurrence in burn patients and factors relevant with mortality in these patients. Patients and Methods: This cross-sectional study was performed in one year on 81 burn patients. We collected patient data regarding age, body weight and height, cause of burn, lesion color and place and percentage of burn. Then we documented all interventions, blood tests and cultures and recorded colonies criteria. Results: Thirty-nine males (48.1%) and 42 females (51.9%) included with a mean age of 32.06 ± 17.46 years. In patients without bacteremia, 57 patients did not need catheterization (89.1%), however in patients with bacteremia, nine needed a catheter (52.9%).. In this survey, in patients with bacteremia, 12 survived (70.9%), however in those without bacteremia, 56 patients survived (92.2%). Then, the relativity between the type of burn and wound infection bacteria species was investigated, but analysis found a P value of 0.65, which was not significant. Conclusions: Invasive interventions increased bacteremia susceptibility in burn wards. Mortality rate had a direct association with bacteremia prevalence and increased by larger burn area.

Urinary proteins, vitamin D and genetic polymorphisms as risk factors for febrile urinary tract infection and relation with bacteremia: a case control study.

Objective/PurposeFebrile urinary tract infection (UTI) is a common bacterial disease that may lead to substantial morbidity and mortality especially among the elderly. Little is known about biomarkers that predict a complicated course. Our aim was to determine the role of certain urinary cytokines or antimicrobial proteins, plasma vitamin D level, and genetic variation in host defense of febrile UTI and its relation with bacteremia.MethodsA case-control study. Out of a cohort of consecutive adults with febrile UTI (n = 787) included in a multi-center observational cohort study, 46 cases with bacteremic E.coli UTI and 45 cases with non-bacteremic E.coli UTI were randomly selected and compared to 46 controls. Urinary IL-6, IL-8, LL37, β-defensin 2 and uromodulin as well as plasma 25-hydroxyvitamin D were measured. In 440 controls and 707 UTI patients polymorphisms were genotyped in the genes CXCR1, DEFA4, DEFB1, IL6, IL8, MYD88, UMOD, TIRAP, TLR1, TLR2, TLR5 and TNF.ResultsIL-6, IL-8, and LL37 are different between controls and UTI patients, although these proteins do not distinguish between patients with and without bacteremia. While uromodulin did not differ between groups, inability to produce uromodulin is more common in patients with bacteremia. Most participants in the study, including the controls, had insufficient vitamin D and, at least in winter, UTI patients have lower vitamin D than controls. Associations were found between the CC genotype of IL6 SNP rs1800795 and occurrence of bacteremia and between TLR5 SNP rs5744168 and protection from UTI. The rare GG genotype of IL6 SNP rs1800795 was associated with higher β-defensin 2 production.ConclusionAlthough no biomarker was able to distinguish between UTI with or without bacteremia, two risk factors for bacteremia were identified. These were inability to produce uromodulin and an IL6 rs1800795 genotype.

Occurrence of Bacteremia in Patients with Chronic Periodontitis

Occurrence of Bacteremia in Patients with Chronic Periodontitis

Epidemiology and antimicrobial susceptibility trends of methicillin-resistant Staphylococcus aureus in a tertiary hospital

Introduction: Staphylococcus aureus is a major cause of health care associated infections worldwide. Objective: The aim of this work was to evaluate epidemiological characteristics and antimicrobial susceptibility of Methicillin-resistant S . aureus (MRSA) strains isolates from infections in a Brazilian tertiary hospital. Methods: Clinical and epidemiological data of the patients were collected. Bacterial strains were isolated and identified using the classical identification tests. Antimicrobial susceptibility assays were performed using the disc-diffusion method. Findings: A total of 590 samples of S. aureus were isolated from patients and 42.5% were characterized as MRSA. Considering the clinical specimens, most of samples were isolated from blood and tracheal secretion, catheter tip, surgical site swabs, wound secretion, exudates and urine. Overall, a high frequency of resistance was observed against ciprofloxacin, clindamycin, erythromycin, amikacin, gentamicin, trimethoprim-sulfamethoxazole, tetracycline and chloramphenicol. Association between death and multidrug-resistance in elderly patients, and death and occurrence of bacteremia by multidrug-resistant MRSA was observed. Conclusions: Our data are highly relevant for surveillance systems and to map on a wider scale the dynamics of circulation of MRSA and raise discussions on containment strategies and rational use of empiric chemotherapy.

Prevalence of bacteremia in dairy cattle with acute puerperal metritis

Dairy cattle are susceptible to numerous disorders in the immediate post-partum period. Acute puerperal metritis (APM), defined as the presence of a fetid, watery uterine discharge, an enlarged, flaccid uterus, and overt signs of systemic illness that may include fever, dehydration, depression, and toxemia, is one of the most commonly encountered infectious diseases in modern dairy practice. After calving, more than 90% of cattle experience some degree of contamination of the uterine lumen with bacteria. Through the processes of uterine involution and normal immune function, most cattle clear this contamination and experience no complications. However, cattle with retained placenta, hypocalcemia, and significant negative energy balance fail to clear uterine contamination and develop APM. Bacteremia has been documented in approximately 32% of adult dairy cattle with coliform mastitis. In cows with acute coliform mastitis, the presence of bacteremia, particularly blood borne infection with organisms such as E. coli, Pasteurella multocida and Mannheimia hemolytica, had a significant impact on cow survival. The purposes of the study reported here were to investigate the prevalence of bacteremia in dairy cattle with naturally occurring APM, determine if an association exists between the bacteria cultured from the bloodstream and those present in uterus and identify factors that may be of use in predicting occurrence of bacteremia in cattle with APM.

Risk Factors and Outcome Analysis of Acinetobacter baumannii Complex Bacteremia in Critical Patients*

Acinetobacter baumannii complex bacteremia has been identified increasingly in critical patients admitted in ICUs. Notably, A. baumannii complex bacteremia has a high mortality rate, yet the risk factors associated with mortality remain unclear and controversial. Retrospective study. All adult ICUs at a tertiary care medical center. All patients with A. baumannii complex bacteremia admitted in 2009-2010. None. Risk factors for mortality were analyzed. Bacterial isolates were identified by 16S-23S ribosomal RNA intergenic spacer region sequencing for genospecies and genotyped by pulsed-field gel electrophoresis. Carbapenemase genes were detected by polymerase chain reaction and sequencing. A total of 298 patients met the inclusion criteria, including 73 (24.5%) infected by imipenem-resistant A. baumannii complex. The overall 30-day mortality was 33.6% (100 of 298). Imipenem-resistant A. baumannii complex bacteremia specifically showed a high mortality (69.9%) and was associated with prior use of broad-spectrum antibiotics for more than 5 days for treating ventilator-associated pneumonia before the occurrence of bacteremia. Mortality was associated with inappropriate initial antimicrobial therapy, which was correlated with imipenem-resistant A. baumannii complex but not with any specific genospecies. ISAba1-blaOXA-23-ISAba1 (Tn2006) was found in most (66.7%, 40 of 68) imipenem-resistant A. baumannii (genospecies 2) and also spread beyond species border to all imipenem-resistant genospecies 3 (2), 13TU (2), and 10 (1). For critical patients with A. baumannii complex infection, ventilator-associated pneumonia in particular, the selective pressure from prior use of broad-spectrum antibiotics for 5 days or more increased risk of subsequent imipenem-resistant A. baumannii complex bacteremia. To reduce mortality, rapid identification of imipenem-resistant A. baumannii complex and early initiation of appropriate antimicrobial therapy in these high-risk patients are crucial.

Mucositis not neutropenia determines bacteremia among hematopoietic stem cell transplant recipients

In the 1960s, it was reported that infectious complications were the main cause of fever during neutropenia that followed hematopoietic stem cell transplant (HSCT). More recently, mucositis has become recognized as an important determinant of the inflammatory response and infectious complications. The objective of this prospective study was to determine the impact of intestinal mucositis, as measured by plasma citrulline, and neutropenia on the systemic inflammatory response (C-reactive protein) and the occurrence of bacteremia among 2 cohorts of HSCT recipients: 1 composed of 18 patients who had been treated with a myeloablative (MA) regimen (high-dose melphalan) and the other involving 19 patients who had received the non-myeloablative (NMA) regimen (fludarabine and cyclophosphamide). Blood cultures were obtained for surveillance from admission onwards as well as at the onset of fever. The MA regimen induced severe intestinal mucositis manifest by citrullinemia <10 μmol/L, which was accompanied by an inflammatory response, and bacteremia affected 8 (44%) of 18 patients and coincided with the nadir of citrullinemia. By contrast, those who had been treated with the NMA regimen did not develop severe intestinal mucositis, had a moderate inflammatory response, and only 2 (11%) of the 19 patients developed bacteremia. However, both groups experienced profound neutropenia and its duration was significantly longer for those receiving the NMA regimen. This study suggests that severe intestinal mucositis, i.e., citrullinemia <10 μmol/L, defines the period of risk of bacteremia better than does neutropenia, and that measuring plasma citrulline may prove useful in deciding who needs empirical antimicrobial therapy and when.

Bacteraemia in Ventricular Assist Devices: A Common Complication that Need Not Affect Clinical Outcomes

Ventricular assist device (VAD) implantation has become an effective option for patients with severe heart failure. However, device-related infections remain a significant problem. The aim of this study was to describe the incidence and microbiological aetiology of bacteraemia in patients with VADs, and to assess the impact of bacteraemia on clinical outcomes. A retrospective study was conducted of patients having VAD implantation at the Alfred Hospital (Melbourne, Australia) from October 1990 to July 2009. Medical records and microbiology databases were reviewed. Patients who were supported with a VAD for 72h or more were evaluated for demographic data, VAD type, the occurrence of bacteraemia and clinical outcomes. During the 19-year period, 135 VAD patients (89 Thoratec PVAD, 10 Novacor, and 36 Ventrassist) supported for a total duration of 17,304 (median 74) support days were included. Sixty-one patients (45%) developed VAD-associated bacteraemia, an incidence of 5.6 episodes per 1000 support days. The incidence of bacteraemia per 1000 days of support was similar for the three devices used: Thoratec PVAD, Novacor and Ventrassist VADs (7.8±0.8, 5.2±1.5 and 3.4±0.5, respectively, p=0.74). Staphylococcus aureus was the most common pathogen (25%). The rates of death on device, survival to transplant, recovery with explant and outcomes after transplantation, including 30-day mortality, median survival time and incidence of cerebrovascular accidents were not significantly impacted upon by bacteraemia. Bacteraemia is common in VAD patients. However, the incidence of VAD-associated bacteraemia is independent of device type and with aggressive antimicrobial therapy; clinical outcomes need not be affected by the bacteraemia.

Bacteriemia por Shigellaflexneri serotipo 6 en pacientes con SIDA: Presentación de dos casos clínicos

Infections due to Shigella usually remain localized to the digestive tract and are self-limited. Bacteremia is a potentially lethal complication that can occur in immunocompromised patients. We describe two episodes of bacteremia caused by Shigella in two adults with AIDS. In both patients, S. flexneri was recovered from stool and blood samples. The isolates belonged to serotype 6, were resistant only to trimethoprim-sulfamethoxazole and showed a similar band profile by pulsed-field gel electrophoresis. Patients received prolonged antimicrobial treatment with a favorable outcome. There were no cases of diarrhea in other individuals admitted to the emergency room. We hypothesized that patient No. 2 was infected at the hospital from patient No. 1. However, we could not establish the way of transmission. Although rare, it is important to take into account the possible occurrence of bacteremia due to Shigella or other bacterial enteropathogens in immunocompromised patients with diarrhea.

Investigation of bacteremia induced by removal of orthodontic mini-implants

The aim of this study was to investigate potential occurrence of bacteremia in orthodontic patients after removal of miniscrews.The study group comprised 30 healthy subjects (17 males, 13 females) with a mean age of 24.1 years treated with self-ligating fixed appliances and mini-implant anchorage. Two 20 ml venous blood samples were obtained prior to and 30-60 seconds after miniscrew explantation following an aseptic technique. Blood culturing in aerobic and anaerobic conditions was carried out by means of the BACTEC blood culture analyzer. Microbiological analysis showed that none of the pre- and post-operative samples exhibited detectable bacteremia. Future research should be focused on determining the collective bacteremic effect of a sequence of orthodontic procedures including miniscrew placement or removal, typically performed during a single treatment session.

Metastatic Complications of Bloodstream Infections in Hemodialysis Patients

Bacteremia is a common infectious complication in hemodialysis patients. Metastatic sites of infection including infective endocarditis, vertebral osteomyelitis, spinal epidural abscess, and septic arthritis occur relatively frequently. These complications are associated with increased morbidity and mortality in hemodialysis patients. Early clinical recognition and appropriate management of these infections are necessary, and strategies to reduce the occurrence of bacteremia in this patient population are warranted.

262 Whether Multi-Resistant Strains of Non-Typhoid Salmonellosis affect Clinical Manifestations and Outcomes in Children?

ObjectiveThe aim of the study was to investigate whether multi-resistant strains of non-typhoid salmonellosis affect clinical manifestations and outcomes in children.MethodsBetween 1996 and 2009, children with nontyphoid salmonellosis admitted to...

A newly developed optical biochip for bacteria detection based on DNA hybridization

This paper reports a bacterial optical biochip based on a developed DNA hybridization detection method using an optical measurement. Because the occurrence of bacteremia caused by Acinetobacter baumannii is high in hospitals worldwide, this species was chosen as the source of the DNA samples. Our strategy is based on a developed DNA hybridization detection method which uses probes, PCR-amplified bacterial DNA with biotin labeled primers as well as detection enhancement using gold–streptavidin nanoparticles and an Ag +–hydroquinone solution. Because the gold nanoparticles catalyze silver ions to silver metals by using hydroquinone, the gradually precipitated silver metal causes differences in the optical detection signals, which can be easily observed with the naked eye or with an optical instrument (such as a flatbed scanner). The relationships between sample concentration and detection signal are discussed, and the detection limit for Acinetobacter baumannii genomic DNA is 8.25 ng/mL (1.07 × 10 10 copy/mL). Probe specificity was analyzed by detecting various species of bacteria, various strains of a single species, and various species of a single genus. The DNA hybridization detection method for the bacterial optical biochip presented in this work is easy, rapid, convenient, and promising for detecting bacterial infections and in clinical diagnoses.

Bacteremia due to multidrug-resistant (MDR) and extended-spectrum beta-lactamase (ESBL) producing Acinetobacter baumannii

Bacteremia due to Acinetobacter baumannii is a common problem in hospitals worldwide. Physicians in the intensive care units (ICUs) encountered a serious challenge of finding a drug to cure the extended-spectrum beta-lactamase (ESBL) producing and multi-drug resistant (MDR) A. baumannii bacteremia. Our aim was to determine the frequency of A. baumannii bacteremia in an Iranian hospital ICUs, their antibiotic susceptibility patterns, and the frequency of ESBLs by a cross-sectional study. A total of 340 patients admitted to ICUs during a 6 month period of study were investigated for bacteremia due to A. baumannii. Bacteria isolates from blood specimens were identified as A. baumannii by API 20NE system. Antimicrobial susceptibility was studied with disk diffusion method. Detection of ESBLs was done by double disk synergy test. Of the 340 patients investigated, bacteremia was found in 114 cases (33%). A. baumannii was diagnosed as the etiological agent of bacteremia in 69 cases (60.5%). All the isolates were multi-drug resistant. Except one, all the remaining isolates (98.6%) were resistant to at least 7 of 13 tested antibiotics. Pandrug-resistance was observed in 4 isolates (5.6%). Of all the isolated A. baumannii, 49 (71%) were found to be resistant to cephalosporins by screening tests and among them 27 isolates (39%) were found to be ESBL producing.Our study showed a high frequency of A. baumannii bacteremia occurrence in our hospital ICUs. An urgent intervention is needed to reduce the MDR bacterial load in these critical units. Key words: Acinetobacter baumannii, bacteremia, multi-drug resistant, extended-spectrum beta-lactamase.

Comparação entre citrato trissódico e heparina como solução para selo de cateter em pacientes em hemodiálise

The high incidence of patients beginning dialysis treatment with venous catheters, as well as the growing number of patients with permanent catheter access, has increased catheter- related blood infections and their consequences. Thus the search for substances with anticoagulant properties that also prevent catheter contamination is necessary. This study aimed at comparing heparin and trisodium citrate used as long-term catheter locking solutions regarding the occurrence of pyrogenic reaction, bacteremia, infection- related hospitalizations, thrombosis, and death. Retrospective study on the infection data from the Infection and Adverse Event Prevention Control Program registry, which included all hemodialysis patients using long-term catheters from April, 2006 to March, 2008. During the first 365 days, catheters were locked with heparin (Heparin group) and, during the following 365 days, with 46.7% trisodium citrate (Citrate group). Sixty-five patients were included in the study using 92 catheters. The groups were compared regarding the occurrence of pyrogenic reaction, bacteremia, hospitalization, catheter thrombosis, and death. The catheter-related bacteremia episodes were significantly lower and hospitalization time was significantly shorter in the Citrate group when compared with those in the Heparin group. A tendency towards a lower occurrence of access site infection-related hospitalization was observed in the Citrate group (p = 0.055), and no difference was observed in catheter thrombosis leading to dysfunction between groups. Bacteremia-free and hospitalization-free times were longer in the Citrate group. The occurrence of bacteremia was associated with the presence of diabetes and heparin use. In multivariate analysis, being in the Heparin group was the only factor associated with bacteremia. The use of 46.7% citrate solution effectively reduced bacteremia episodes and hospitalization in chronic kidney disease patients on hemodialysis with long-term catheters.

Effects of gastric mucosa washing with povidone-iodine solution on bacteremia after endoscopic ultrasonography-guide fine needle aspiration

Objective To study the occurrence of bacteremia and whether washing gastric mucosa with povidone-iodine could reduce its occurrence after endoscopic uhrasonography （EUS） -guided fine needle aspiration （FNA）. Methods A total of 20 healthy adult dogs were randomly assigned into experimental group and control group, with 10 in each. The animals in experimental group underwent gastric mucosa washing with 10 ml 0. 5% povidone-iodine solution before FNA, while those in control group with 10ml norreal saline. Blood samples were collected for culture before EUS, between EUS and FNA, and 5, 15 and 30 minutes after FNA. Results There were 3 cases of positive bacteremia in experimental group and 1 in control group,which were not significantly different （ P = O. 582）. Conclusion Pre-washing gastric mucosa with 0. 5% povidone-iodine solution cannot reduce bacterial infection after EUS-guided FNA. Key words: Endosonography; Biopsy, fine-needle ; Bacteremia; Cell culture techniques; Povidone-iodine solution

Temporal Changes in the Incidence and 30-Day Mortality associated with Bacteremia in Hospitalized Patients from 1992 through 2006: A Population-based Cohort Study

Little is known about temporal trends in the incidence and mortality associated with bacteremia in the general population. We conducted a population-based cohort study in Northern Denmark to examine changes in bacteremia occurrence and 30-day mortality from 1992 through 2006. All patients who received a diagnosis of bacteremia were identified in a population-based bacteremia database and followed up for mortality through the Danish Civil Registry System. We determined the overall annual age- and sex-standardized rates of bacteremia episodes, the incidence of first-time episodes, and the adjusted 30-day mortality by place of acquisition and study period. We identified 14,303 bacteremia episodes, 11,703 (81.8%) of which were incident. The age- and sex-standardized overall rate of bacteremia increased by 68% from 1992 through 2006, and the incidence increased by 46% (from 114 to 166 episodes per 100,000 person-years). Community-acquired and nosocomial bacteremia incidence rates peaked at 92.1 and 77.2 episodes per 100,000 person-years in 2004 and 2002, respectively, whereas the incidence of health care-associated bacteremia increased steadily from 2.9 to 39.8 episodes per 100,000 person-years. Total number of deaths increased from 742 during 1992-1996 to 926 during 2002-2006. The 30-day mortality decreased in patients with community-acquired bacteremia (19.0% during 1992-1996 vs 15.4% during 2002-2006) but remained nearly unchanged for health care-associated (23.4% and 22.0%, respectively) and nosocomial bacteremia (27.9% and 27.7%, respectively). The occurrence of bacteremia in Northern Denmark, regardless of the place of acquisition, increased considerably in the past 15 years, and bacteremia was associated with persistently high 30-day mortality. Thus, bacteremia remains a clinical and public health concern.

Intestinal Damage Determines the Inflammatory Response and Early Complications in Patients Receiving Conditioning for a Stem Cell Transplantation

BackgroundStem cell transplantation (SCT) is still complicated by the occurrence of fever and inflammatory complications attributed to neutropenia and subsequent infectious complications. The role of mucosal barrier injury (MBI) of the intestinal tract therein has received little attention.MethodsWe performed a retrospective analysis in 163 SCT recipients of which data had been collected prospectively on intestinal damage (citrulline), inflammation (C-reactive protein), and neutrophil count. Six different conditioning regimens were studied; 5 myeloablative (MA) and 1 non-myeloablative (NMA). Linear mixed model multivariate and AUC analyses were used to define the role of intestinal damage in post-SCT inflammation. We also studied the relationship between the degree of intestinal damage and the occurrence of early post-SCT complications.ResultsIn the 5 MA regimen there was a striking pattern of inflammatory response that coincided with the occurrence of severe intestinal damage. This contrasted with a modest inflammatory response seen in the NMA regimen in which intestinal damage was limited. With linear mixed model analysis the degree of intestinal damage was shown the most important determinant of the inflammatory response, and both neutropenia and bacteremia had only a minor impact. AUC analysis revealed a strong correlation between citrulline and CRP (Pearson correlation r = 0.96). Intestinal damage was associated with the occurrence of bacteremia and acute lung injury, and influenced the kinetics of acute graft-versus-host disease.ConclusionThe degree of intestinal damage after myeloablative conditioning appeared to be the most important determined the inflammatory response following SCT, and was associated with inflammatory complications. Studies should explore ways to ameliorate cytotoxic therapy-induced intestinal damage in order to reduce complications associated with myeloablative conditioning therapy.

Infections during induction therapy for children with acute lymphoblastic leukemia. The role of sulfamethoxazole–trimethoprim (SMX–TMP) prophylaxis.

Bacteremias are frequent during induction therapy for acute lymphoblastic leukemia (ALL) in children. Antibacterial prophylaxis therapy may thus be warranted. The purpose of this study was to analyze the rate of infections during induction therapy in two cohorts of children with ALL where one cohort received prophylactic sulfamethoxazole-trimethoprim (SMX-TMP). All infections were registered through a retrospective non-randomized review of medical records of 171 consecutive children newly diagnosed with ALL below 15 years of age at diagnosis. A total of 85 children treated from 1992 to 2000 did not receive SMX-TMP, whereas 86 children treated from 2000 to 2008 received SMX-TMP 20 mg/kg in one daily oral dose during induction therapy. A total of 26% of all children had no febrile episodes during induction. Infections were more frequent in children below 5 years of age. Significantly fewer children receiving SMX-TMP developed fever (17% vs. 34%, P = 0.02) and bacteremia (20% vs. 45%, P = 0.0003). Especially children with non-high risk criteria had fewer infections when receiving prophylaxis. When adjusting for age, type of catheter, and SMX-TMP prophylaxis on the risk of bacteremia by a multiple Cox regression analysis, we found that age and prophylaxis, but not the type of catheter, were associated with a significantly reduced risk of bacteremia. Children with ALL receiving SMX-TMP prophylaxis during induction therapy experienced fewer febrile episodes, fewer days with fever demanding intravenous antibiotic treatment, and fewer episodes of bacteremia. Both SMX-TMP prophylaxis and age played significant independent roles for the occurrence of bacteremia.