High Pitt Bacteremia Score Research Articles

Bloodstream infections in adult patients with cancer: clinical features and pathogenic significance of Staphylococcus aureus bacteremia

The aim of this study was to more precisely delineate the characteristics and outcomes of bloodstream infections in adult cancer patients. Using a database for nationwide surveillance of bacteremia, we analyzed data related to bacteremia in adult patients with cancer in order to evaluate clinical features and outcomes and to define predictive factors for mortality. Of 1,246 patients, 896 (71.9%) had solid tumors, 328 (26.3%) had hematologic malignancies, and 22 (1.8%) had both. The following conditions were more common in the neutropenic group than in the non-neutropenic group: nosocomial acquisition, hematologic malignancy, corticosteroid use, immunosuppressant use, primary bacteremia, and pneumonia (all P < 0.05). The infections were caused by Gram-negative bacilli in 55.6% and by Gram-positive cocci in 32.7%. Gram-negative pathogens were more frequently isolated from neutropenic patients than from non-neutropenic patients (61.9% vs. 53.5%, P = 0.010), with a significant predominance of Escherichia coli and Klebsiella pneumoniae. Among 1,001 patients whose outcomes could be evaluated, the overall 30-day mortality rate was 24.1%, and multivariate analysis showed that Staphylococcus aureus bacteremia was a significant factor associated with mortality (odds ratio (OR), 1.80; 95% confidence interval (CI), 1.03-3.15), along with nosocomial acquisition, pneumonia, severe sepsis or septic shock, and higher Pitt bacteremia score (all P values <0.05). This study represents the comprehensive assessment of bloodstream infections in neutropenic versus non-neutropenic cancer patients. Given the pathogenic significance of S. aureus bacteremia in adult patients with cancer, additional strategies for the management of S. aureus bacteremia in cancer patients are needed to improve outcomes.

Characteristics and outcomes of Fusobacterium nucleatum bacteremia—a 6-year experience at a tertiary care hospital in northern Taiwan

Fusobacterium nucleatum bacteremia is critical and not well defined. To identify the clinical characteristics and outcomes, we conducted a retrospective review of hospitalized patients from January 2004 to December 2009 at a tertiary center in northern Taiwan. Fifty-seven patients were enrolled. The mean age was 58.1 years, and the mean Pitt bacteremia score was 4.7. Males predominated (59.6%), and the overall 30-day mortality rate was up to 47.4%. Malignancy was the major comorbidity (26/57, 45.6%), especially oropharyngeal and gastrointestinal cancers (19/26, 73.1%). Pneumonia (17/57, 29.8%) was the most common presentation with high rates of respiratory failure (15/17, 88.2%) and mortality (11/17, 64.7%), followed by intra-abdominal infections (7/57, 12.3%). In multivariate analysis, higher Pitt bacteremia score, nosocomial infection, anemia, and intensive care unit stay were the independent factors for 30-day mortality. Nosocomial F. nucleatum bacteremia was a significant mortality predictor independent to other parameters of disease severities.

Risk factors for infection and treatment outcome of extended-spectrum β-lactamase-producing Escherichia coli and Klebsiella pneumoniae bacteremia in patients with hematologic malignancy

This study was performed to evaluate the impact of extended-spectrum β-lactamase (ESBL)-producing bacteremia on outcome in patients with hematologic malignancy. We collected and analyzed data on 156 hematologic malignancy patients with Escherichia coli or Klebsiella pneumoniae bacteremia from the database of nationwide surveillance studies for bacteremia. Thirty-seven of the 156 patients (23.7%) harbored ESBL-producing bacteremia. No significant differences in underlying diseases were found in either group. The multivariate analysis showed that significant factors associated with ESBL-producing bacteremia were ICU care (OR = 7.03, 95% CI = 1.79-27.6) and nosocomial acquisition (OR = 5.66, 95% CI = 1.60-20.23). There was an association between prior receipt of cephalosporins and ESBL-producing bacteremia, although this association was not statistically significant (OR = 2.27, 95% CI = 0.99-5.23). The overall 30-day mortality rate of the study population was 20.4% (29/142), and the 30-day mortality rate for the ESBL group was significantly higher than that for the non-ESBL group (44.8% vs. 14.2%, P < 0.001). Multivariate analysis showed that ESBL-producing bacteremia was the most important risk factor associated with 30-day mortality (OR, 5.64; 95% CI, 1.91-16.67), along with ICU care (OR = 4.35, 95% CI = 1.16-16.26) and higher Pitt bacteremia score (per 1-point increment) (OR = 1.50, 95% CI = 1.18-1.92). In conclusion, ESBL-producing bacteremia was the most important risk factor associated with 30-day mortality in patients with hematologic malignancy, along with ICU care and higher Pitt bacteremia score. Our data suggest that determining the optimal empiric antimicrobial therapy in patients with hematologic malignancy is now becoming a challenge for clinicians in the era of multidrug-resistant Gram-negative bacilli.

Clinical and microbiological characterization of carbapenem-resistant Acinetobacter baumannii bloodstream infections

The incidence of carbapenem-resistant Acinetobacter baumannii infection is increasing, which might be associated with high morbidity and mortality among critically ill patients with limited therapeutic options. This study was conducted to evaluate the clinical and microbiological features of carbapenem-resistant A. baumannii bacteraemia. The medical records of 28 adult patients with this bacteraemia admitted to Korea University Guro Hospital, from January 2005 through December 2010, were reviewed. Using the 28 bloodstream isolates, we intended to detect genes encoding carbapenemases, and investigate the inoculum effect on each of the antimicrobial agents rifampicin, imipenem, colistin and tigecycline. With one blood isolate from a patient with pneumonia, rifampicin-inducible resistance was examined using the experimental mouse pneumonia model. Out of 28 carbapenem-resistant A. baumannii bloodstream infections (BIs), the most common primary focus was the central venous catheter (35.7 %) and then the lung (32.1 %). The 30 day overall mortality was 53.6 %; in most cases (80 %) the patients died within 10 days after the onset of the bacteraemia. By univariate analysis, inappropriate antimicrobial therapy (73.3 vs 30.8 %, P = 0.02), mechanical ventilation (53.3 vs 15.4 %, P = 0.04) and a high Pitt bacteraemia score (4.9±1.9 vs 2.2±1.2, P<0.01) were statistically significant risk factors for mortality, while only a high Pitt bacteraemia score (odds ratio 2.6; 95 % confidence interval 1.1-6.5) was independently associated with 30 day mortality by multivariate analysis. All 28 isolates had the bla(OXA-51)-like gene with upstream ISAbaI, 2 of which additionally had the bla(OXA-58)-like gene and the bla(OXA-23)-like gene. Inoculum effect and rifampicin inducible resistance were not detected. Considering the rapid progression to death in carbapenem-resistant A. baumannii BIs, early empirical antibiotic therapy would be warranted based on the local microbiological data in each hospital.

Clinical significance of nosocomial acquisition in urinary tract–related bacteremia caused by gram-negative bacilli

Although hospital-acquired infections presumably may have a poorer prognosis than community-onset infections because of unanticipated antimicrobial resistance, little data are available on the clinical and microbiological characteristics of hospital-acquired versus community-onset urinary tract-related bacteremia cases. Data were collected from a nationwide database of surveillance for bacteremia. Data from patients with hospital-acquired urinary tract-related bacteremia were compared with those with community-onset bacteremia. Of 398 patients with urinary tract-related bacteremia, 71 (17.8%) had hospital-acquired infection, and the remaining 327 (82.2%) had community-onset infection. Although Escherichia coli was the most common isolate identified, pathogens other than E coli were more frequently isolated in hospital-acquired infections than in community-onset infections (46.5% vs 19.3%). Among E coli isolates causing hospital-acquired infections, 26.3% (10 of 38) were resistant to extended-spectrum cephalosporins (ESCs), whereas among E coli isolates causing community-onset infections, only 6.1% (16 of 264) were ESC-resistant. Hospital-acquired infection had a significantly higher mortality rate than community-onset infection (21.1% [15 of 71] vs 8.3% [27 of 327]; P=.004). Multivariate analysis identified nosocomial acquisition as a significant independent risk factor for mortality, along with severe sepsis, underlying solid tumor, ESC resistance, and high Pitt bacteremia score (all P < .05). Hospital-acquired urinary tract-related bacteremia has a poorer prognosis than community-onset bacteremia. TheESC-resistant nature of gram-negative bacilli, which may be more common in nosocomial isolates than in community isolates, adversely affects the outcome of urinary tract-related bacteremia.

Clinical Characteristics and Risk Factors for Fatality in Patients with Bloodstream Infections Caused by Glucose Non-fermenting Gram-negative Bacilli

Glucose non-fermenting Gram-negative bacilli (GNF-GNB) bloodstream infections (BSIs) are often hospital-acquired and are important causes of morbidity and mortality. Our objectives were to evaluate the epidemiology and clinical characteristics of GNF-GNB BSIs, and to identify risk factors for fatality. We retrospectively reviewed cases of GNF-GNB BSIs in adult patient (≥ 18 years of age) hospitalized between January and December 2005. A total 221 GNF-GNB bacteremic episodes (200 hospital-acquired and 21 community-acquired) in 215 patients (123 men and 92 women; mean age, 63.38±16.10 years) were included in our study. Of these, 52.5% were elderly (age > 65). Malignancy (43.0%), diabetes mellitus (22.6%) and steroid use (22.6%) were the major underlying diseases/conditions. Central venous catheter (CVC) placement had been carried out in 57.5% of patients. The 28-day mortality was significantly higher in those patients with: liver cirrhosis, steroid use, pneumonia as the primary source of infection, intensive care unit-acquired infections, septic shock, and a high Pitt bacteremia score (≥ 4 points). Liver cirrhosis [odds ratio (OR)=6.4; 95% confidence interval (CI)=1.7-23.9; p < 0.01)], hematologic malignancy (OR=3.9; 95% CI=1.1-14.1; p=0.04), pneumonia (OR=4.0; 95% CI=1.4 - 11.0; p< 0.01), septic shock (OR=13.0; 95% CI=4.6-36.6; p< 0.01), and intensive care unit-acquired infections (OR=2.9; 95% CI=1.1-8.0; p= 0.04) were all independent risk factors for fatality. Our data suggested that CVC placement and steroid use predispose to GNF-GNB bacteremia. Early removal of CVC and avoidance of steroids may minimize the chances of acquiring this infection, which is of particular importance for patients at high risk of mortality once they are infected with GNF-GNB.

Aeromonas Spontaneous Bacterial Peritonitis: A Highly Fatal Infectious Disease in Patients with Advanced Liver Cirrhosis

Aeromonas infections, rarely reported in Western countries, are not uncommon infectious diseases in Taiwan. The clinical manifestations and prognostic factors of Aeromonas spontaneous bacterial peritonitis (SBP) in patients with liver cirrhosis were investigated. We reviewed the medical charts and microbiological records of liver cirrhosis patients with Aeromonas SBP between January 1990 and December 2005, in a medical center in southern Taiwan. Thirty-one liver cirrhosis patients developed Aeromonas SBP within a 16-year period. The majority (26, 84%) had concurrent Aeromonas bacteremia. A. sobria (55%) and A. hydrophila (45%) were the causative species. The predominant clinical manifestations included fever (84%), abdominal pain (74%), hypotension on admission (48%), altered mental status (45%), and acute renal failure (42%). Gram-negative bacilli were found in Gram staining of ascitic fluids in 27% of 26 patients, while aeromonads were isolated from ascitic fluids in 55% of 31 patients. The yield rate of ascitic fluid cultures decreased greatly, if paracentesis was performed at > 3 hours after the administration of antimicrobial therapy. All but one patient received in-vitro-active antimicrobial agents within 48 hours, but the all-cause mortality rate was 56%. Initial high Pitt's bacteremia score was independently associated with a fatal outcome in multivariate analysis. Aeromonas SBP is a fatal disease, and must be included in the differential diagnosis of SBP in patients with advanced liver cirrhosis in endemic areas.

Clinical Significance and Predictors of Community-Onset Pseudomonas aeruginosa Bacteremia

Background Pseudomonas aeruginosa bacteremia is a serious and possibly fatal condition. It is important to determine the likelihood of P. aeruginosa bacteremia when Gram-negative sepsis is suspected in community-onset infection. Methods We performed a retrospective cohort study to identify the risk factors for P. aeruginosa infection in community-onset Gram-negative bacteremia. Results A total of 106 patients with P. aeruginosa bacteremia and a total 508 patients with E. coli bacteremia were included in this study. Factors associated with P. aeruginosa bacteremia in the multivariate analysis included presentation with neutropenia, presentation with septic shock, indwelling central venous catheter, and health-care-associated infection (all P <.05). The 30-day mortality rate was 26.4% in patients with P. aeruginosa and 13.6% in those with E. coli bacteremia ( P <.001). Multivariate analysis demonstrated that risk factors for mortality included a P. aeruginosa bacteremia, inappropriate initial antimicrobial therapy, a higher Charlson's weighted index of comorbidity, and a higher Pitt bacteremia score (all P <.05). In addition, urinary tract infection and benign pancreatobiliary disease were found to be protective factors for mortality based on multivariate analysis (all P <.05). Conclusions Our data suggest that initial empirical antimicrobial coverage of P. aeruginosa should be seriously considered in patients with neutropenia, presentation with septic shock, indwelling central venous catheter, or health-care-associated infection, when Gram-negative sepsis is suspected in community-onset infection.

Inappropriate initial antimicrobial therapy as a risk factor for mortality in patients with community-onset Pseudomonas aeruginosa bacteraemia

This study was performed to identify the risk factors for mortality and evaluate the effect of inappropriate initial antimicrobial therapy on the outcomes of patients with community-onset Pseudomonas aeruginosa bacteraemia in an emergency department (ER) setting. All cases with P. aeruginosa bacteraemia occurring within 48 h after ER visit from January 2000 to December 2005 were retrospectively analysed. A total of 106 community-onset P. aeruginosa bacteraemia cases in the ER were included (mean age, 57.61 +/- 14.44 years old; M:F, 58:48). Although P. aeruginosa bacteraemia was diagnosed in the ER, most of the cases of P. aeruginosa bacteraemia were healthcare-associated (88.7%). Malignancy (n = 83, 78.3%) was the most common underlying disorder. Fifty patients (47.2%) were neutropaenic and 56 patients (52.8%) had septic shock. The overall 30-day mortality rate was 26.4% (28/106). In the univariate analysis, underlying malignancy, high Charlson's weighted index of comorbidity (> or = 3), high Pitt bacteraemia score (> or = 4), indwelling central venous catheter and inappropriate initial therapy were significantly associated with 30-day mortality (all P < 0.05). In the multivariate analysis, high Pitt bacteraemia score (OR, 17.03; 95% CI, 4.60-63.15; P < 0.001) and inappropriate initial antimicrobial therapy (OR, 4.29; 95% CI, 1.39-13.24; P = 0.011) were found to be significant risk factors for 30-day mortality. The 30-day mortality rate was significantly higher in the inappropriate therapy group (18/51, 35.3%) than in the appropriate therapy group (10/55, 18.2%) (P = 0.046). This study demonstrated that inappropriate initial antimicrobial therapy was significantly associated with unfavourable outcomes in patients with community-onset P. aeruginosa bacteraemia. As P. aeruginosa bacteraemia can be a fatal infection, even when community-onset, inappropriate antimicrobial therapy should be avoided in suspected cases of P. aeruginosa bacteraemia.

Clinical significance of healthcare-associated infections in community-onset Escherichia coli bacteraemia

The increasing antimicrobial resistance of Escherichia coli infection is of great concern, even for community-onset infections. We conducted a retrospective cohort study of patients with E. coli bacteraemia who visited the emergency department of the Samsung Medical Center from February 2002 to December 2005 to identify the risk factors for mortality and association between healthcare-associated (HCA) infection and mortality. We classified community-onset E. coli bacteraemia into community-acquired (CA) and HCA infections. A total of 508 patients with E. coli bacteraemia were enrolled (mean age, 61.8 +/- 14.3 years; male/female, 191:317). The HCA E. coli bacteraemia had significantly higher severity of illness and higher antimicrobial resistance rate than CA bacteraemia. The overall 30-day mortality rate was 13.6% (69/508) and the mortality of HCA infections was significantly higher than that of CA infections (26.4% versus 9.6%, P < 0.001). In multivariate analysis, high Charlson's co-morbidity index (OR 4.84, 95% CI 2.14-10.95, P < 0.001), high Pitt bacteraemia score (OR 32.03, 95% CI 13.08-74.43, P < 0.001), presentation with acute renal failure (OR 4.11, 95% CI 1.90-8.89, P < 0.001) and HCA bacteraemia (OR 2.34, 95% CI 1.09-5.01, P = 0.030) were found to be the significant risk factors for 30-day mortality in E. coli bacteraemia. The mortality rate of HCA E. coli bacteraemia was higher than twice that of CA bacteraemia and HCA bacteraemia was one of the significant risk factors for mortality, even after adjusting for a large number of potential confounders.

Treatment of ESBL-producing Klebsiella pneumoniae bacteraemia with carbapenems or flomoxef: a retrospective study and laboratory analysis of the isolates

To better understand the clinical outcomes of patients with extended-spectrum beta-lactamase-producing Klebsiella pneumoniae (ESBL-KP) bacteraemia treated with either flomoxef or a carbapenem, and to evaluate the in vitro activities of these antibiotics against ESBL-KP. Retrospective analyses to identify risk factors for mortality in patients with flomoxef-susceptible ESBL-KP, especially addressing the therapeutic roles of flomoxef and carbapenem. In vitro activities of flomoxef and carbapenem against flomoxef-susceptible ESBL-KP isolates were evaluated by susceptibility testing and time-kill study. Twenty-seven patients (flomoxef group, n=7; carbapenem group, n=20) were included. Clinical severity reflected by high Pitt bacteraemia score (>or=6) was an independent risk factor for mortality (OR 13.43; 95% CI, 1.08-166.73; P=0.043), while use of flomoxef or a carbapenem was not. The MICs of flomoxef and carbapenem indicated that the tested ESBL-KP were susceptible to these antibiotics regardless of the inoculum size of 10(5) or 10(7) cfu/mL. Time-kill study showed that these antibiotics (flomoxef 8 mg/L and meropenem 4 mg/L) each acted actively against and inhibited the regrowth of the tested ESBL-KP for at least 24 h. Flomoxef might be as clinically effective as a carbapenem in treating flomoxef-susceptible ESBL-KP bacteraemia.