Factors predisposing cancer patients to infection

Molecular and Clinical Data of Antimicrobial Resistance in Microorganisms Producing Bacteremia in a Multicentric Cohort of Patients with Cancer in a Latin American Country

Patients with cancer have a higher risk of severe bacterial infections. This study aims to determine the frequency, susceptibility profiles, and resistance genes of bacterial species involved in bacteremia, as well as risk factors associated with mortality in cancer patients in Colombia. In this prospective multicenter cohort study of adult patients with cancer and bacteremia, susceptibility testing was performed and selected resistance genes were identified. A multivariate regression analysis was carried out for the identification of risk factors for mortality. In 195 patients, 206 microorganisms were isolated. Gram-negative bacteria were more frequently found, in 142 cases (68.9%): 67 Escherichia coli (32.5%), 36 Klebsiella pneumoniae (17.4%), and 21 Pseudomonas aeruginosa (10.1%), and 18 other Gram-negative isolates (8.7%). Staphylococcus aureus represented 12.4% (n = 25). Among the isolates, resistance to at least one antibiotic was identified in 63% of them. Genes coding for extended-spectrum beta-lactamases and carbapenemases, blaCTX-M and blaKPC, respectively, were commonly found. Mortality rate was 25.6% and it was lower in those with adequate empirical antibiotic treatment (22.0% vs. 45.2%, OR: 0.26, 95% CI: 0.1-0.63, in the multivariate model). In Colombia, in patients with cancer and bacteremia, bacteria have a high resistance profile to beta-lactams, with a high incidence of extended-spectrum beta-lactamases and carbapenemases. Adequate empirical treatment diminishes mortality, and empirical selection of treatment in this environment of high resistance is of key importance.

Safety of Percutaneous Internal Jugular Catheterization in Cancer Patients: Prospective Observational Study

Purpose

To determine predictors for failure and early complications of percutaneous internal jugular catheterization (IJC) in cancer patients.

Methods

Six hundred and thirty consecutive cancer patients who required central venous catheterization were included in a prospective observational study. The rates of failure (defined as the intervention of a second physician and/or failure at initial insertion site) and of early complications were prospectively ascertained. Logistic regression analysis estimated odds ratio (OR) and 95% confidence intervals (95% CI) for independent predictors for failure and early complications of percutaneous IJC.

Results

The failure rate was 6.7%, and the early complication rate was 6.7%. In multivariate analysis, left-side initial catheterization (p<0.01), prior catheterization at the same site (p=0.001) and physician inexperience (p<0.0001) were independently associated with failure. Placement requiring more than one needle pass (p<0.01 for two and p<0.0001 for three and more) and absence of fluoroscopy (p<0.0001) were independently associated with early complications.

Conclusions

Percutaneous IJC is a valid option in the central venous catheterization of cancer patients due to its reliability and safety. Skilled physicians must manage difficult placements. If placement requires more than one needle pass or is made without fluoroscopy, patients must be carefully followed for potential complications.

Nosocomial infections and fever of unknown origin in pediatric hematology/oncology unit: a retrospective annual study

BACKGROUND

pediatric hematology/oncology patients are faced with an increased risk of nosocomial infections (NIs) that vary in different populations and different institutions with considerable morbidity and mortality. This study was undertaken to assess the frequency and patterns of NIs in 1564 pediatric patients and to determine the prevalence of causative organisms and their antimicrobial sensitivity.

METHODS

a retrospective analysis was made in the patients admitted between January 2007 and January 2008 to the pediatric hematoloy/oncology unit of Mansoura University, Egypt. The 1564 patients showed 2084 admissions and 27 092 inpatient days. The Centers for Disease Control and Prevention criteria were used as a standard definition for NI.

RESULTS

the overall rate of NIs in all patients and neutropenic patients was 8.6 and 25.3 per 1000 patient-days respectively. The frequent sites of NIs were blood stream (42.7%), the respiratory system (25.3%), the urinary system (22.2%) and the central nervous system (9.8%), whereas nosocomial fever of unknown origin constituted 52.9% of cases. The incidence of NIs was significantly higher during neutropenic days (P<0.001). Gram-positive organisms represented 64.5% of pathogens (Staphylococci 71.5%, Streptococci 16%, and pneumococci 7%), and Gram-negative organisms represented 30% (E. coli 48.6%, Klebsiella 15.7%, Pseudomonas 35.7%, and C. albicans 5.5%). Positive cultures were more frequent in summer (July to September). Susceptibility of isolated organisms was relatively low (cefoperazone/sulbactam 49.9%, amikacin 35.9%, imipenem/cilastin 34.4%, cefoperazone 33.6%, and vancomycin 36.5%). Methicillin-resistant S. aureus, extended spectrum beta lactamase and vancomycin resistant enterococci represented 30%, 45% and 75% of isolated S. aureus, Gram-negative organisms and Enterococci, respectively.

CONCLUSIONS

blood stream infection and fever of unknown origin are the most common nosocomial infections in pediatric hematology/oncology patients with a higher risk during neutropenic days. Isolated organisms are multi-drug resistant, predominantly Gram-positive pathogens with a high incidence of methicillin-resistant S. aureus, extended spectrum beta lactamase and vancomycin resistant enterococci organisms.

Febrile neutropenia

This review summarizes the current status and diagnostic-therapeutic challenges in febrile neutropenia. Patients with neutropenia-associated infections have a poor prognosis. A large meta-analysis of trials assessing prophylactic antibiotics has shown significant survival benefits; clinical significance of resistance is unclear. Administering broad-spectrum antibiotics to established febrile neutropenic patients has become selective, vancomycin is withheld unless absolutely necessary, and low-risk patients are identified with biological markers. Such patients are now managed with oral antibiotics at home or even without antibiotics. Protracted prolonged neutropenia is the setting par excellence for invasive fungal infections. Conventional amphotericin B administered to such risk patients reduces the incidence of fungal infections. New antifungal drugs have heightened efficacy and lowered toxicity. Novel antifungal diagnostic tests include imaging, particularly the CT "halo" sign (aspergillosis), and serology (glucan, galactomannan), and provide earlier diagnosis and treatment and better outcomes. Negative tests may indicate withholding antifungal therapy. High intermittent dosing of liposomal amphotericin B seems as safe and as effective as standard dosing regimens, but at half the drug acquisition cost. The use of nonantibiotic agents has offered alternative management strategies. Recombinant interleukin-11 reduces bacteremia, through a cytoprotective mechanism on the gut. rhIL-11 releases C-reactive protein and causes shedding of soluble TNF receptor-1, modulating the immunological milieu and the systemic inflammatory response. Other candidate molecules include RANTES and long-pentraxin 3. Recombinant growth factors reduce febrile episodes, permitting completion of chemotherapy, increase overall survival, and minimize infection mortality.

Continuous antibiotic infusion for salvage therapy of partially implanted central venous catheter tunnel infections due to staphylococci

Tunnel infection is an uncommon but serious complication observed in patients with partially implanted central venous catheters. International guidelines suggest that should include antibiotics and catheter removal. A success rate of only 5-20% was reported without catheter removal. We treated 13 episodes of tunnel Gram-positive bacterial infection occurring in pediatric patients with cancer or serious blood disorders with 24-hr intra-catheter antibiotic continuous infusion. This approach led to a 69% success rate. Continuous infusion might be an attractive option to treat tunnel Gram-positive bacterial infections when catheter removal might not be feasible or advisable.

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.

Infections in Patients with Febrile Neutropenia: Epidemiology, Microbiology, and Risk Stratification

Determinations of the type and setting of empirical therapy for immunocompromised patients with fever are complicated by the characteristics of the underlying illness and the effects of treatments already received, as well as by changing microbiological patterns and trends in drug resistance at national and institutional levels. Several systems have been proposed to distinguish patients who could benefit from outpatient antibiotic therapy from patients who require hospitalization. Practical considerations may decide whether the necessary monitoring during the period of neutropenia can be achieved.

Étude sur sept ans des isolats d’hémocultures dans un service d’hématologie clinique

GOAL

This study had for aim to analyze the epidemiology of strains identified in blood cultures (hôpital d'instruction des armées Percy, Clamart, France, hematology unit) to compare the rate of identified micro-organisms with literature data, and to search for a possible correlation between antibiotherapy management and evolution of resistance profiles.

MATERIAL AND METHODS

All the micro-organisms (N = 690) collected over seven years (January 1996 to December 2002), from blood cultures of hospitalized patients in conventional and sterile sector were studied.

RESULTS

Gram positive cocci rate (GPC) was 62.6% and Gram negative bacilli (GNB) 31.3%. Evolution in time showed a decrease of GPC and an increase of GNB, notably the non fermenting Gram negative bacilli, leading to an equal rate by 2001-2002. The most frequently identified species were Staphylococcus epidermidis (36.4%), Escherichia coli (8.7%), Pseudomonas aeruginosa (6.8%), and Staphylococcus aureus (4.9%). The rate of methicillin-resistant staphylococci was 63.6%. Fifty-five percent of E. coli strains had a penicillinase phenotype. Pseudomonas aeruginosa resistance was 8.5, 8.5, 6.4 and 8.5%, respectively for ceftazidime, piperacillin-tazobactam, imipenem, and amikacin.

CONCLUSION

This study showed a tendency to inversion of former bacteremia epidemiology with increasing negative Gram bacilli. It justifies the antibiotherapy protocols adopted in the hematology unit.

Prevention of life-threatening infections due to encapsulated bacteria in children with hyposplenia or asplenia: a brief review of current recommendations for practical purposes

The aim of the present work was to summarise in a single paper all the options for prevention of life-threatening infections due to encapsulated bacteria in patients with hyposplenism or asplenia. Prevention of these infections should be obtained in all patients with 1) patient and family education, 2) prophylaxis by means of vaccination against Haemophilus influenzae and Streptococcus pneumoniae, 3) antibiotic prophylaxis, based primarily on penicillin, 4) delay of elective splenectomy or use methods of tissue salvage in splenic trauma. Vaccination is not effective against all serotypes of S. pneumoniae and Neisseria meningitidis causing life-threatening infections in hypo/asplenic patients. Moreover, antibacterial prophylaxis could select antibacterial-resistant pathogens and is highly conditioned by patient's compliance. Therefore, empirical antibacterial therapy of fever and/or suspected infection should be recommended to all splenectomised patients independently from time elapsing from splenectomy, vaccinal status and assumption of antibacterial prophylaxis.

Treatment of febrile neutropenia: what is new?

PURPOSE OF THE REVIEW

To identify the more recent challenges in the treatment of patients with febrile neutropenia following antineoplastic chemotherapy or bone marrow transplant published in the English language in the period late 2000-early 2002 regarding: changes in etiology of bacteremia in neutropenic patients; new options for initial empirical antibacterial therapy; factors associated with the risk of developing infection in cancer patients; prediction of prognosis in febrile neutropenia; oral therapy; need for a specific anti-Gram-positive coverage in persistently febrile and neutropenic patients.

RECENT FINDINGS

Findings may be summarized according with the identified topics as follows: many centers are reporting an increase in the incidence of Gram-negative bacteremias; piperacillin-tazobactam could be safely administered as monotherapy of febrile neutropenia; congenital factors and intensity of chemotherapy and other medical interventions, such as antifungal prophylaxis, are recognized as of increasing importance in the determination of infectious risk; it is now possible to identify patients with a good prognosis (low risk) by means of validated scoring systems; oral therapy is feasible in low risk patients; the empirical addition of a glycopeptide in persistently febrile neutropenic patients is not indicated.

SUMMARY

Many of the identified points may have a great impact in the daily management of febrile granulocytopenic patients. However, all recent epidemiological and therapeutical studies underline the absoloute need for the knowledge of the pattern of infecting organisms in each center.

Incidence of septicaemias and invasive mycoses in children undergoing treatment for solid tumours: a 12-year experience at a single Italian institution

We carried out a retrospective study on the infection rate--in episodes per 100 person months at risk (p/m/r)--of septicaemia and invasive mycoses in children with solid tumours treated at a single institution between 1985 and 1996. Among 982 patients, accounting for 8108 p/m/r, 257 infectious episodes were documented, for an infection rate of 3.2. The infection rate for "intensive" treatment was greater than that for "less intensive" treatments, 3.7 compared with 0.5, respectively; P<0.001. 58% of infectious episodes were associated with neutropenia, 22% were megatherapy-related, and 39% were related to central venous catheter (CVC), while in 13% of the episodes no risk factor was identified. Of the episodes, single organism Gram-positive bacteraemias accounted for 62%, single organism Gram-negative for 23%, multiple organism bacteraemias for 7%, invasive mycoses for 4%, and isolated fungaemias for 4%. The infection rate for Gram-positive organisms decreased significantly over time (-5.9% per year; P<0.01), but increased for the Gram-negative organisms (+3.4% per year; P=0.4). This study demonstrates that the risk of bacteraemia increases in parallel with the treatment intensity, and that a considerable number of children with solid tumours develop bacteraemia in the absence of an identifiable risk factor.