Israel Medical Association Journal

Background: Recent data regarding polymicrobial bacteremia (PMB) are lacking.

Objectives: To characterize risk factors as well as clinical, microbiological, and prognostic patterns of patients with PMB in a modern hospital setting.

Methods: A single center retrospective study including all patients diagnosed with PMB during 2013 was conducted. PMB was defined as two or more organisms cultured from the blood of the same patient within 72 hours. Patients with monomicrobial infections served as controls.

Results: There were 135 episodes (2% of all bacteremia episodes) of true PMB among 123 patients during the study period. Recent invasive procedures (odds ratio [OR] 3.59, 95% confidence interval [95%CI] 1.41–9.12, P = 0.006) and foreign bodies (OR 1.88, 95%CI 1.06–3.33, P = 0.04) were risk factors for PMB when compared with 79 patients with monomicrobial bacteremia. Central-line-associated infections were the most common infection source among patients with PMB (n=34, 28%). Enterobacteriaceae were the most commonly implicated pathogen (n=95, 77%). Non-fermenting Gram-negative bacilli were significantly more common than previously reported (n=55, 45%). Although crude 30-day mortality was higher (48% vs. 33%) in PMB patients, adjusted mortality was comparable in the two groups.

Conclusions: PMB rate in our cohort was considerably lower than in previous reports. Central-line-associated infections were more common than classic PMB sources. Mortality remained high. Strategies for early identification and better care for these patients should be pursued.

Background: Monitoring the rate of infections in individual centers that treat patients with hematological malignancies is of major importance. However, there are no uniform guidelines for infection surveillance.

Objectives: To describe the epidemiology of bacterial and fungal infections in a single hematology ward and to compare methods for reporting surveillance and infection rates in other centers in Israel.

Methods: We conducted a prospective surveillance of all patients admitted to our hematology ward, applying standard definitions for invasive fungal infections and adapting definitions for non-fungal infections. Incidence rates were calculated using patients, admissions, hospital days and neutropenia days. We performed a search for other reported surveillance studies in Israel.

Results: We detected 79 infectious episodes among 159 patients admitted to the hematology ward during 1 year. Using neutropenia days as the denominator for calculation of incidence discriminated best between patients at high and low risk for infection. The incidence of invasive fungal infections was 7, 10 and 18 per 1000 neutropenia days, among all patients, those with acute leukemia and those with acute leukemia undergoing induction therapy, respectively. Only 10 reports from Israel were identified, 6 of which were prospective. Our data could not be compared to these reports because of the varying definitions and denominators used.

Conclusions: Hematology centers should monitor infection rates and report them in a uniform methodology.
 

Background: The epidemiology of bacteremic febrile neutropenia differs between locations and constitutes the basis for selection of empiric antibiotic therapy for febrile neutropenia.

Objectives: To describe the epidemiology of bacteremia among patients with neutropenia in a single center in Israel.

Methods: We conducted a prospective data collection on all patients with neutropenia (< 500/mm³) and clinically significant bacteremia or fungemia during the period 1988–2004.

Results: Among adults (462 episodes) the most common bloodstream isolate was Esherichia coli. Gram-negative bacteria predominated throughout the study period and the ratio between Gram-negative and Gram-positive bacteremia increased from 1.7 to 2.3 throughout the study period. Among children (752 episodes), the ratio between Gram-negative and Gram-positive bacteremia reversed from 1.2 to 0.7, due to increasing prevalence of coagulase-negative staphylcoccal bacteremia. Both among adults and children, the length of hospital stay prior to bacteremia had a major impact on the pathogens causing bacteremia and their antibiotic susceptibilities. The prevalence of E. coli decreased with time in hospital, while the rates of Pseudomonas aeruginosa, Klebsiella pneumoniae, Enterobacter spp., Acinetobacter spp., Enterococcus spp. and Candida spp. increased. Resistance to broad-spectrum empiric monotherapy in our center was observed in > 40% of Gram-negative bacteria when bacteremia was acquired after 14 days in hospital.
Conclusions: Improved infection-control measures for neutropenic cancer patients in our center are needed. Empiric antibiotic treatment should be tailored to patients’ risk for multidrug-resistant organisms. Individual hospitals should monitor infection epidemiology among cancer patients to guide empiric antibiotic treatment