Prospective evaluation of the epidemiology, microbiology, and outcome of bloodstream infections in hematologic patients in a single cancer center

Sex-Disaggregated Analysis of Central Venous Catheter-Related Bloodstream Infections in Patients with Cancer

INTRODUCTION

Men are generally more susceptible to bacterial infections than women. Central venous catheters (CVCs), often used to administer systemic treatment in patients with cancer, are an important source of infection. However, little is known about sex-specific differences of CVC-related bloodstream infections (CRBSIs) in patients with cancer. This study aimed to compare CRBSIs in men versus women in a large cohort of patients with cancer.

METHODS

Data were derived from the SECRECY registry including nonselected patients with centrally inserted non-tunneled internal jugular or subclavian vein CVCs in 10 hematology and oncology sites in Germany. Only CRBSIs classified as definite CRBSI (dCRBSI) or probable CRBSI were included, and the combination of both was summarized as dpCRBSI. CVCs were matched 1:1 for underlying disease, anatomic site of CVC insertion, type of CVC dressing, antimicrobial coated CVC, complicated CVC insertion, and CVC in situ time by propensity score matching (PSM). Endpoints were CRBSI rates and incidences in CVCs inserted in men versus women.

RESULTS

A total of 5,075 CVCs registered from March 2013 to March 2024 were included in the analysis, of which 3,024 comprise the PSM cohort. A total of 1,512 (50.0%) CVCs were inserted in men. Underlying diseases mainly were hematological malignancies (96.4%). While there was no statistically significant difference between men and women in the dCRBSI rate (5.4% vs. 4.1%; p = 0.12) and the dCRBSI incidence (3.8 vs. 2.9/1,000 CVC days; p = 0.11), the rate of dpCRBSI (9.9% vs. 6.7%; p = 0.002) and the dpCRBSI incidence (7.0 vs. 4.7/1,000 CVC days; p = 0.002) were significantly higher in men versus women. The proportion of coagulase-negative staphylococci as causative agent of both dCRBSI and dpCRBSI was higher in men than in women (58.8% vs. 41.2%; p = 0.07 and 61.5% vs. 38.5%; p = 0.002, respectively). A multivariable regression revealed neutropenia as an independent risk factor for dCRBSI and male sex as risk factor for dCRBSI and dpCRBSI.

CONCLUSION

In patients with hematological malignancies, men have a higher risk of CRBSI than women. This finding may be attributed to the high number of jugular vein-inserted CVCs, which in men may be associated with higher rates of skin colonization than in women. Special preventive measures such as earlier removal of CVCs in men may be studied in future.

INTRODUCTION

Men are generally more susceptible to bacterial infections than women. Central venous catheters (CVCs), often used to administer systemic treatment in patients with cancer, are an important source of infection. However, little is known about sex-specific differences of CVC-related bloodstream infections (CRBSIs) in patients with cancer. This study aimed to compare CRBSIs in men versus women in a large cohort of patients with cancer.

METHODS

Data were derived from the SECRECY registry including nonselected patients with centrally inserted non-tunneled internal jugular or subclavian vein CVCs in 10 hematology and oncology sites in Germany. Only CRBSIs classified as definite CRBSI (dCRBSI) or probable CRBSI were included, and the combination of both was summarized as dpCRBSI. CVCs were matched 1:1 for underlying disease, anatomic site of CVC insertion, type of CVC dressing, antimicrobial coated CVC, complicated CVC insertion, and CVC in situ time by propensity score matching (PSM). Endpoints were CRBSI rates and incidences in CVCs inserted in men versus women.

RESULTS

A total of 5,075 CVCs registered from March 2013 to March 2024 were included in the analysis, of which 3,024 comprise the PSM cohort. A total of 1,512 (50.0%) CVCs were inserted in men. Underlying diseases mainly were hematological malignancies (96.4%). While there was no statistically significant difference between men and women in the dCRBSI rate (5.4% vs. 4.1%; p = 0.12) and the dCRBSI incidence (3.8 vs. 2.9/1,000 CVC days; p = 0.11), the rate of dpCRBSI (9.9% vs. 6.7%; p = 0.002) and the dpCRBSI incidence (7.0 vs. 4.7/1,000 CVC days; p = 0.002) were significantly higher in men versus women. The proportion of coagulase-negative staphylococci as causative agent of both dCRBSI and dpCRBSI was higher in men than in women (58.8% vs. 41.2%; p = 0.07 and 61.5% vs. 38.5%; p = 0.002, respectively). A multivariable regression revealed neutropenia as an independent risk factor for dCRBSI and male sex as risk factor for dCRBSI and dpCRBSI.

CONCLUSION

In patients with hematological malignancies, men have a higher risk of CRBSI than women. This finding may be attributed to the high number of jugular vein-inserted CVCs, which in men may be associated with higher rates of skin colonization than in women. Special preventive measures such as earlier removal of CVCs in men may be studied in future.

Peripherally inserted central catheter-related bloodstream infections in patients with hematological malignancies: A retrospective 7-years single-center study

OBJECTIVES

We sought to investigate the nature and incidence of bloodstream infection complications and to identify the risk factors of central catheter-related bloodstream infections (CRBSI).

METHODS

During the study period, 291 consecutive patients with hematological malignancies who underwent PICC placement were retrospectively enrolled. We analyzed the covariates that were specified a priori for their association with CRBSI through multivariate Cox proportional hazards regression models. The association between each predictor and the related outcome was expressed using hazard ratios (HRs) with corresponding 95% confidence intervals (CIs).

RESULTS

Of 391 peripherally inserted central catheter (PICCs) were inserted in 291 patients for a total of 63,714 catheter days during 7 years, with an infection rate of 0.71/1,000 catheter days. Among the patients with hematological malignancies, those with acute leukemia were prone to CRBSI. Having previous bloodstream infection (BSI) (HR 18.139; 95% CI, 8.19-40.174; P < .0001), the number of PICCs insertions (HR 4.695; 95% CI, 1.842-11.967; P = .001) (twice), (HR 6.794; 95% CI, 1.909-24.181; P = .003) (≥3 times) were significantly associated with CRBSI. Not accompanied by chronic comorbidities (HR 0.34; 95% CI, 0.131-0.887; P = .028) and longer duration of PICC use (days) (HR 0.997; 95% CI, 0.994-0.999; P = .008) might be protective factors preventing CRBSI.

CONCLUSIONS

Our finding suggests that previous BSI and a higher number of PICC insertions are associated with an increased risk of CRBSI. A lack of chronic comorbidities may help prevent CRBSI.

Current Sites of Infections and Types of Microorganisms in Patient with Febrile Neutropenia in Hematological Wards – Single Center Study

BACKGROUND: Febrile neutropenia occurs in more than 80% of patients with hematological malignances specially after chemotherapy cycles and an infectious source is identified in approximately 20–30%. Various bacterial, viral, and fungal pathogen contribute to the development of neutropenic fever and without prompt antibiotic therapy mortality rate can be as high as 70%. AIM: The objective of the study was to document the current sites of infection in patients with febrile neutropenia in hematological ward in Baghdad Teaching Hospital, the microorganisms and antibiotic susceptibly in culture positive cases and mortality rate in 1 week and 4 weeks after episode of fever. PATIENTS AND METHODS: One hundred cases of febrile neutropenia were evaluated in Hematological Ward of Baghdad Teaching Hospital from January 2019 to January 2020. Detailed history, physical examination, and laboratory investigations were conducted and statistical analysis of the results was done. RESULTS: One hundred cases of febrile neutropenia, mean age of presentation was 41.56 ± 10.5 years. Acute myeloid leukemia (36%) and acute lymphocytic leukemia (26%) were the most common underlying hematological disorder, followed by Aplastic Anemia, Non-Hodgkin Lymphoma, and Hodgkin Lymphoma. Temperature ranged from 38°C to 39°C with mean temperature of 38.4°C and most of the patient presented with short duration of fever, 57% had absolute neutrophil count below 150 cells/μL with mean duration of neutropenia was 14.01 days. Respiratory tract was the most common site of infection (52%) followed by urinary tract (18%) and in 16% had no obvious focus of infection. Thirty percent of cases were culture Gram-positive and Gram-negative microorganism which were more common 62.9% which were generally sensitive to Aminoglycosides while Gram-positive microorganism constituted 29.6% of isolated bacteria and were generally sensitive to vancomycin. No mortality documented 1 and 4 weeks after fever. CONCLUSION: We concluded that the most frequent sites of infection in patient with febrile neutropenia were respiratory tract followed by urinary tract infection, while 16% had undetermined source of infection. Thirty percent of patients had a positive blood culture with Escherichia coli being the most common infecting microorganism, Gram-negative microorganisms were more common than Gram-positive microorganism and fungal infection constituted about 6% of growth. Significant association was found between the fever and longer duration of neutropenia and the greater severity of neutropenia was observed. No mortality related to febrile neutropenia was documented.

A practical update on the epidemiology and risk factors for the emergence and mortality of bloodstream infections from real-world data of 3014 hematological malignancy patients receiving chemotherapy

Background: Bloodstream infection (BSI) is a common and serious complication after patients with hematologic malignancies (HM) receiving chemotherapy. This study examined real-world data seeking to characterize HM BSI and identify risk factors for BSI emergence and mortality.

Methods: We retrospectively analyzed the pathogenic epidemiology, antibiotic resistance, and BSI risk factors in a single-center cohort including 3014 consecutive patients with HM receiving chemotherapy between 2013 and 2016. Results of the pathogenic epidemiology were validated via comparison to available reported data.

Results: We found that 725 patients (24.1%) had BSIs. Gram-negative (G-) bacteria represented 64.7% of the 744 isolated pathogenic strains, while Gram-positive (G+) bacteria and fungi accounted for 27.7% and 7.7% of the BSIs, respectively. The most common isolates were Klebsiella pneumoniae (19.2%), and 95.1% of the multidrug-resistant strains (MDR) were extended-spectrum beta-lactamase producing strains. G- bacteria were the main microflora responsible for BSI in our cohort of Chinese HM patients compared to studies in developed countries or in neutropenic children with HM or solid tumors. Multivariate analysis revealed that male sex, age ≥ 45 and < 65 yr, hospital length of stay ≥ 9d, neutropenia ≥ 7d before cultures, ≥ 2 antibiotics, and infections (gastrointestinal, perirectal, or urinary tract) independently predicted BSI emergence. Furthermore, age ≥ 65 yr, neutropenia ≥ 7d before blood cultures, no HM remission, lower white blood cell count, ≥ 3 antibiotics, respiratory infections, and Acinetobacter baumannii and Stenotrophomonas maltophilia BSI were independent predictors of 30-day mortality.

Conclusions: G- bacteria were the predominant microflora during the study period and antibiotic resistance levels of the pathogens detected were high, especially for MDR strains. The mortality of BSI patients was high in this large cohort. Close attention should be paid to the risk factors identified here to facilitate timely and effective clinical management of such patients.

Bloodstream infections in patients with or without cancer in a large community hospital

PURPOSE

Cancer is associated with an increased risk of acquiring bloodstream infection (BSIs). Most knowledge on pathogens and outcome are derived from specialised cancer centres. We here sought to compare causative micro-organisms in BSIs in patients with or without cancer in a 600-bed teaching community hospital.

METHODS

We analysed all positive blood cultures from adult patients between January 2005 and January 2011.

RESULTS

A total of 4,918 episodes of BSI occurred in 2,891 patients, of whom 13.4% had a diagnosis of cancer (85.5% with a solid tumour). In both patient groups, Gram-positive isolates were more prevalent (58.7 and 61.4% in patients with and without cancer, respectively) than Gram-negative isolates (31.8 and 32.3%, respectively). Amongst Gram-positive organisms, coagulase-negative staphylococci, Staphylococcus aureus and enterococci were the most frequently isolated in both patient groups; in cancer patients, twice as many BSIs were caused by Enterococcus faecalis and E. faecium. Amongst Gram-negative organisms, Escherichia coli was the most common isolate; in cancer patients, twice as many BSIs were caused by Pseudomonas aeruginosa and Enterobacter cloacae. Yeasts were grown from 3.0% of blood cultures from cancer patients compared to 1.5% of cultures from non-cancer patients. Cancer patients had a 90-day mortality of 35.8% following BSI compared to 23.5% in patients without cancer.

CONCLUSION

These data demonstrate distinct BSI pathogens and impaired outcomes in patients with cancer in the setting of a large community teaching hospital.

Incidence and management of infections in patients with acute leukemia following chemotherapy in general wards

We hypothesise that treating patients with acute leukaemia in general wards, with proper hygienic and sanitary practices, would result in the minimum utilisation of resources as compared with the corresponding patients receiving ICU support. For this study, the acute leukaemia patients on induction chemotherapy were kept in general wards and observed for the incidence of neutropenia, resultant neutropenic febriles, the causative organism, and the effect of empirical antimicrobial treatment protocol on the outcome of such infections. Prophylactic anti-fungal therapy and cotrimoxazole therapy improved the outcome of infections. The therapy of neutropenic fever and infections must be adapted according to the risk factors and should include early empiric antifungal therapy. It was observed that the treatment of such patients in general wards could be managed effectively, with the added advantage of optimum utilisation of resources and in a patient-friendly environment, at a reasonable cost to the patients.

Anti-pseudomonal beta-lactams for the initial, empirical, treatment of febrile neutropenia: comparison of beta-lactams

BACKGROUND

Several beta-lactams are recommended as single agents for the treatment of febrile neutropenia.

OBJECTIVES

To compare the effectiveness of different anti-pseudomonal beta-lactams as single agents in the treatment of febrile neutropenia. To compare the development of bacterial resistance, bacterial and fungal superinfections during or following treatment with the different beta-lactams.

SEARCH STRATEGY

We searched the Cochane Register of Controlled Trials (CENTRAL), Issue 3, 2010. MEDLINE, EMBASE, LILACS, FDA drug applications, conference proceedings and ongoing clinical trial databases up to August 2010. References of included studies were scanned.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing an antipseudomonal beta-lactam to another antipseudomonal beta-lactam antibiotic, both given alone or with the addition of the same glycopeptide to both study arms, for the initial treatment of fever and neutropenia among cancer patients.

DATA COLLECTION AND ANALYSIS

Two review authors applied inclusion criteria and extracted the data independently. Missing data were sought. Risk ratios (RR) were calculated with 95% confidence intervals (CI), and pooled using the fixed effect model. The primary outcome was all-cause mortality. Risk of bias was assessed using a domain-based evaluation and its effect of results was assessed through sensitivity analyses.

MAIN RESULTS

Forty-four trials were included. The antibiotics assessed were cefepime, ceftazidime, piperacillin-tazobactam, imipenem and meropenem. Adequate allocation concealment and generation were reported in about half of the trials and only two trials were double-blinded. The risk for all-cause mortality was significantly higher with cefepime compared to other beta-lactams (RR 1.39, 95% CI 1.04 to 1.86, 21 trials, 3471 participants), without heterogeneity and with higher RRs in trials at low risk for bias. There were no differences in secondary outcomes but for a non-significantly higher rate of bacterial superinfections with cefepime. Mortality was significantly lower with piperacillin-tazobactam compared to other antibiotics (RR 0.56, 95% CI 0.34 to 0.92, 8 trials, 1314 participants), without heterogeneity. Carbapenems resulted in similar all-cause mortality and a lower rate of clinical failure and antibiotic modifications as compared to other antibiotics, but a higher rate of diarrhea caused by Clostridium difficile.

AUTHORS' CONCLUSIONS

Current evidence supports the use of piperacillin-tazobactam in locations where antibiotic resistance profiles do not mandate empirical use of carbapenems. Carbapenems result in a higher rate of antibiotic-associated and Clostridium difficile-associated diarrhea. There is a high level of evidence that all-cause mortality is higher with cefepime compared to other beta-lactams and it should not be used as monotherapy for patients with febrile neutropenia.

Infection probability score, APACHE II and KARNOFSKY scoring systems as predictors of infection onset in haematology-oncology patients

AIM

To assess the predictive power of three systems: Infection Probability Score, APACHE II and KARNOFSKY score to the onset of healthcare-associated infections in haematology-oncology patients.

BACKGROUND

The high incidence of healthcare-associated infections is a frequent problem in haematology-oncology patients that affects morbidity and mortality of these patients.

DESIGN

A retrospective surveillance survey.

METHOD

The survey was conducted for seven months in the haematology unit of a general hospital in Greece to assess the predictive power of Infection Probability Score, APACHE II and KARNOFSKY score to the onset of healthcare-associated infections. The sample consisted of 102 hospitalised patients. The diagnosis of healthcare-associated infections was based on the definitions proposed by CDC.

RESULTS

Among the participants, 53 (52%) were males and 49 (48%) were females with a mean age of 53.30 (SD 18.59) years old (range, 17-85 years). The incidence density of healthcare-associated infections (the number of new cases of healthcare-associated infections per 1000 patient-days) was 21.8 infections per 1000 patient-days. Among the 102 patients, healthcare-associated infections occurred in 32 (31.4%) patients who had a total of 48 healthcare-associated infections (47.5%). Among the 38 patients with neutropenia, 26 (68.4%) had more than one healthcare-associated infection. Of the 48 detected healthcare-associated infections, the most frequent type was blood-stream infection (n = 17, 35.4%), followed by Clostridium difficile infection (n = 11, 22.9%) and respiratory tract infection (n = 8, 3.4%). The best cut-off value of Infection Probability Score (IPS) for the prediction of a healthcare-associated infection was 10 with sensitivity of 59.4% and specificity of 74.3%.

CONCLUSIONS

Between the three different prognostic scoring systems, IPS had the best sensitivity in predicting healthcare-associated infections.

RELEVANCE TO CLINICAL PRACTICE

IPS is an effective tool and should be used from nurses for the early detection of haematology-oncology patients who are susceptible to the onset of a healthcare-associated infection.

Modulation of macrophage cytokine profiles during solid tumor progression: susceptibility to Candida albicans infection

BACKGROUND

In order to attain a better understanding of the interactions between opportunist fungi and their hosts, we investigated the cytokine profile associated with the inflammatory response to Candida albicans infection in mice with solid Ehrlich tumors of different degrees.

METHODS

Groups of eight animals were inoculated intraperitoneally with 5 x 106 C. albicans 7, 14 or 21 days after tumor implantation. After 24 or 72 hours, the animals were euthanized and intraperitoneal lavage fluid was collected. Peritoneal macrophages were cultivated and the levels of IFN-gamma, TNF-alpha, IL-12, IL-10 and IL-4 released into the supernatants were measured by ELISA. Kidney, liver and spleen samples were evaluated for fungal dissemination. Tumor-free animals and animals that had only been subjected to C. albicans infection were used as control groups.

RESULTS

Our results demonstrated that the mice produced more IFN-gamma and TNF-alpha and less IL-10, and also exhibited fungal clearance, at the beginning of tumor evolution. With the tumor progression, this picture changed: IL-10 production increased and IFN-gamma and TNF-alpha release decreased; furthermore, there was extensive fungal dissemination.

CONCLUSION

Our results indicate that solid tumors can affect the production of macrophage cytokines and, in consequence, affect host resistance to opportunistic infections.

Severe sepsis and septic shock: the role of gram-negative bacteremia

Abstract Although Gram-negative bacteria have often been implicated in the pathogenesis of severe sepsis and septic shock, how they trigger these often lethal syndromes is uncertain. In particular, the role played by blood-borne bacteria is controversial. This review considers two alternatives. In the first, circulating Gram-negative bacteria induce toxic reactions directly within the vasculature; in the second, the major inflammatory stimulus occurs in local extravascular sites of infection and circulating bacteria contribute little to inducing toxic responses. Evidence for each alternative is found in the literature. Bacteremia and severe sepsis are not so closely linked that the most striking cases can be a model for the rest. Intravascular and extravascular triggers may warrant different approaches to prevention and therapy.

Comparative study of clinical characteristics of neutropenic and non-neutropenic adult cancer patients with bloodstream infections

A total of 399 consecutive episodes of bloodstream infections in adult patients with haematologic malignancies and solid tumours were evaluated prospectively over a 26-month period, with the aim of determining the clinical characteristics and the microbiological profile of the patients relative to neutrophil count. The overall 30-day mortality rate was 32% (35% in non-neutropenic patients vs. 26% in neutropenic patients, p=0.05). Main diagnoses were solid tumours (33%) and lymphoma (29%). Most of the episodes of bloodstream infection (58%) occurred in non-neutropenic patients. Acute leukaemia and bone marrow transplantation predominated in the neutropenic group. Non-neutropenic patients tended to be older and to have a higher frequency of solid tumours and advanced or uncontrolled diseases. Indwelling central venous catheters were present in 51% of the episodes, with a predominance of long-term catheters in neutropenic haematologic patients. Concomitant infections were observed more frequently in non-neutropenic patients. There were 1,040 noninfectious comorbid conditions, most of which were present in non-neutropenic patients. The causative pathogens were predominantly gram-negative bacilli (56%). Escherichia coli and Klebsiella pneumoniae were isolated more frequently from neutropenic patients, while Staphylococcus aureus and Acinetobacter spp. were more frequent in non-neutropenic patients. Seventy-four percent of the episodes of candidaemia occurred in patients with central venous catheters, with non-albicans strains predominating. The results of this study highlight the heterogeneity of cancer patients with bloodstream infections and the value of stratifying risk factors and aetiologic agents according to neutrophil count.

Low incidence of sepsis due to viridans streptococci in a ten-year retrospective study of pediatric acute myeloid leukemia

BACKGROUND

Infections remain an important cause of morbidity and mortality in children with acute myeloid leukemia (AML), and particularly viridans group streptococci (VGS) sepsis. The present study, conducted between 1993 and 2003 in children with AML, sought to assess the frequency and characteristics of infectious complications (ICs), the incidence of VGS sepsis, the interest of preventive decontamination, and a possible cytarabine dose-effect on the occurrence of ICs.

METHODS

Medical charts of 78 children treated according to the EORTC 58921 clinical trial were analyzed retrospectively. Patients were isolated in laminar air flow rooms, received non-absorbable gut decontamination, gum decontamination with vancomycin mouthwash, and trimethoprim-sulfamethoxasole. ICs were categorized as microbiologically documented infections (MDI), clinically documented infections (CDI), or fever of unknown origin (FUO).

RESULTS

Overall, 268 ICs occurred: 57.5% FUO, 8.5% CDI, and 34% MDI. Bloodstream infections occurred in 58 febrile episodes: Gram-positive bacteria represented 83% of the pathogens including 66.1% Staphylococcus species and 8.5% Streptococcus species (6.8% VGS), Gram-negative bacteria represented 13.5% of the pathogens and yeasts 3.5%. Five patients died of infection (6.4%). None died from bacterial infection and no case of VGS sepsis required intensive care. Invasive fungal infection was proven in four patients. Number of ICs was significantly different according to gum and gut decontamination status, and according to the cytarabine dose during the first intensification. No resistant strains were detected in spite of the use of local antibiotics.

CONCLUSION

The low rate of VGS and enterobacteriaceae sepsis was probably due to the effective decontamination. Our supportive care strategy could potentially help enhance overall survival in children with AML.

Systemic inflammatory response syndrome in adult patients with nosocomial bloodstream infection due to Pseudomonas aeruginosa

OBJECTIVES

To evaluate relationships between the inflammatory response, clinical course, and outcome of nosocomial BSI due to Pseudomonas aeruginosa.

METHODS

We performed a historical cohort study on 77 adults with P. aeruginosa (Pa) nBSI to define the associated systemic inflammatory response syndrome (SIRS). We examined SIRS scores 2 days prior through 14 days after the first positive blood culture. Imipenem resistant--IRPa (n=20) and susceptible infections--ISPa (n=57) were compared. Variables significant in univariate analysis were entered into a logistic regression model.

RESULTS

Seventy-four percent of BSI were ISPa and 26.0% by IRPa. Septic shock occurred in 39.0%. Crude mortality was 48.1%. There was no difference in APACHE II (AP2) scores on days -2, -1 and 0 between the ISPa and IRPa groups. Multivariate analysis revealed that AP2> or =20 at BSI onset (P<0.001) and hematologic failure (P=0.001) independently predicted death.

CONCLUSIONS

In patients with P. aeruginosa nBSI, the incidence of septic shock and organ failure is high; patients with IRPa BSI are not more acutely ill prior to infection than those with ISPa BSI and outcome is not significantly different; AP2> or =20 at BSI onset and the development of hematologic failure are independent predictors of death.

Ceftazidime in acute myeloid leukemia patients with febrile neutropenia: helpfulness of continuous intravenous infusion in maximizing pharmacodynamic exposure

The pharmacokinetic-pharmacodynamic profile of a fixed 6-g daily continuous intravenous infusion of ceftazidime was assessed in 20 febrile neutropenic patients with acute myeloid leukemia. Mean steady-state ceftazidime concentrations averaging 40 mg/liter from day 2 on ensured maximized pharmacodynamic exposure (values close to four to five times the MIC breakpoint against Pseudomonas aeruginosa). However, large intra- and interindividual pharmacokinetic variability was documented throughout the study period.

Bloodstream infections and invasive mycoses in children undergoing acute leukaemia treatment: A 13-year experience at a single Italian institution

The incidence rate (IR) of bloodstream infections (BI) and invasive mycoses (IM) during chemotherapy for paediatric acute lymphoblastic (ALL) or non-lymphoblastic leukaemias (AnLL) was evaluated for 153 BI and 22 IM diagnosed during 143,668 patient-days at risk from January 1988 to December 2000. IR, the number of episodes/100 days at risk, was 0.315 for AnLL and 0.092 for ALL (P < 0.001) with significant changes reflecting the intensity of anti-ALL chemotherapy. IR was 0.097 for first-line less intensive, 0.136 during first-line intensive, 0.261 during second-line therapy (P < 0.001), and 0.021 during maintenance. During intensive chemotherapy, the IR for BI was 0.134 in ALL with 0.087 for first-line less intensive therapy, 0.110 for first-line intensive, 0.230 for second-line intensive therapy (P < 0.001) and 0.274 in AnLL (P = 0.001). IR was 0.021 in ALL and 0.048 in AnLL (P = 0.034) for IM. In conclusion, there is a correlation between intensity of chemotherapy and rate of infections in paediatric acute leukaemias.

Occurrence and antimicrobial resistance pattern comparisons among bloodstream infection isolates from the SENTRY Antimicrobial Surveillance Program (1997-2002)

The empiric treatment of patients with bloodstream infections (BSI) has become more complicated in an era of increasing antimicrobial resistance. The SENTRY Antimicrobial Surveillance Program has monitored BSI from patients in medical centers worldwide since 1997. During 1997-2002, a total of 81,213 BSI pathogens from North America, Latin America, and Europe were tested for antimicrobial susceptibility. S. aureus, E. coli, and coagulase-negative staphylococci were the three most common BSI pathogens in all three regions each year. Prevalence variability was noted in regions for some species, including higher rates of isolation of E. coli in Europe, Enterococcus spp. in North America, and Gram-negative enteric and nonenteric species in Latin America. Patient age analysis showed the most common BSI pathogen among neonates was coagulase-negative staphylococci and among elderly patients, E. coli. Resistance among BSI pathogens was much more prevalent in nosocomial infections and in patients in intensive care units (ICUs); age differences were also noted. Geographically, oxacillin-resistant S. aureus (39.1%, 2002) and vancomycin-resistant enterococci (17.7%, 2002) were highest in North America, and extended-spectrum beta-lactamase-producing Klebsiella spp. (35.8-46.7%) and multidrug-resistant P. aeruginosa (18.7%, 2002) were highest in Latin America. Activity of commonly used antimicrobial agents remained relatively stable in North America, except in the case of vancomycin-resistant enterococci (20% decline between 1997 and 2002). An epidemiologic investigation of oxacillin-resistant S. aureus in North America identified 10 significant clones (ribotypes) and the common resistance patterns associated with them. Surveillance of BSI pathogens is needed to determine trends of resistance and provide useful information regarding patient risk factors and geographic differences.