Carlota Gudiol

Bacteraemia due to multidrug-resistant Gram-negative bacilli in cancer patients: risk factors, antibiotic therapy and outcomes

OBJECTIVES To assess the risk factors, antibiotic therapy and outcomes of multidrug-resistant Gram-negative bacilli (MDRGNB) bacteraemia in hospitalized patients with cancer. METHODS Episodes of MDRGNB bacteraemia were compared with a susceptible control group in a 4 year prospective study. RESULTS Of 747 bacteraemias, 372 (49.7%) were caused by a Gram-negative bacilli (GNB). Fifty-one of these (13.7%) were caused by a multidrug-resistant (MDR) strain. Previous antibiotics [odds ratio (OR) 3.57; 95% confidence interval (CI) 1.63-7.80] and urinary catheter (OR 2.41; 95% CI 1.01-5.74) were identified as independent risk factors for MDRGNB acquisition. The most frequent mechanism of resistance was extended-spectrum β-lactamase (ESBL) production (45%), mainly by Escherichia coli, followed by Amp-C cephalosporinase hyperproduction (24%). Patients with MDRGNB bacteraemia more frequently received inadequate initial antibiotic therapy (69% versus 9%; P < 0.001) and time to adequate therapy was longer in this group (41% versus 4%; P < 0.001). Patients in the resistant group more frequently required intensive care unit (ICU) admission (14% versus 5%; P = 0.023), had greater need for mechanical ventilation (14% versus 3%; P = 0.005) and had a higher overall case-fatality rate (41% versus 21%; P = 0.003). Risk factors for mortality were solid tumour (OR 5.04; 95% CI 2.49-10.19), current corticosteroid use (OR 4.38; 95% CI 2.39-8.05), ICU admission (OR 11.40; 95% CI 3.19-40.74) and MDRGNB bacteraemia (OR 3.52; 95% CI 1.36-9.09). CONCLUSIONS MDRGNB bacteraemia was common among cancer patients, especially in those exposed to antibiotics and urinary catheter. The most frequent mechanism of resistance was ESBL production. Patients with MDRGNB more frequently received inadequate empirical antibiotic therapy and presented poorer outcomes with a higher overall case-fatality rate (within 30 days).

Changing aetiology, clinical features, antimicrobial resistance, and outcomes of bloodstream infection in neutropenic cancer patients

Recent changes in the management of patients with haematological malignancies might have influenced the aetiology, characteristics, antimicrobial resistance and outcomes of bloodstream infection (BSI) during neutropenia. We compared 272 episodes of BSI in adult neutropenic patients with cancer prospectively collected from January 1991 to December 1996 (first period), when quinolone prophylaxis was used, with 283 episodes recorded from January 2006 to March 2010 (second period), when antibacterial prophylaxis was stopped. Patients in the second period were significantly older and were more likely to have graft-versus-host disease and a urinary catheter in place, whereas the presence of a central venous catheter, parenteral nutrition, corticosteroids and antifungal and quinolone prophylaxis, were more frequent in the first period. More patients in the first period had mucositis and soft-tissue infection as the origin of BSI, but an endogenous source was more common during the second. Gram-positive BSI was more frequent in the first period (64% versus 41%; p <0.001), mainly due to coagulase-negative staphylococci and viridans group streptococci. In the second period gram-negative BSI increased (28% versus 49%; p <0.001), quinolone susceptibilities were recovered, but multidrug-resistant gram-negative BSI also increased (1% versus 6%; p <0.001). Although patients in the second period were more likely to need admission to the intensive-care unit, overall case-fatality rate was similar in the two periods (19% versus 15%). The aetiology of BSI in neutropenic patients with cancer has shifted from gram-positive to gram-negative organisms. Multidrug resistance among gram-negative bacilli is emerging as a therapeutic challenge. Overall case-fatality rate remains high.

Serum Galactomannan–Based Early Detection of Invasive Aspergillosis in Hematology Patients Receiving Effective Antimold Prophylaxis

BACKGROUND There is a practical need to investigate the performance of the serum galactomannan (GM) assay in hematology patients with a potentially low pretest risk of invasive aspergillosis following effective antimold prophylaxis. METHODS We present a 4-year study with 262 unselected consecutive high-risk episodes, prospectively managed with posaconazole primary prophylaxis and a uniform diagnostic algorithm, including biweekly serum GM quantification for early detection of invasive aspergillosis. RESULTS A total of 2972 serum GM tests were performed (median, 11 per episode [range, 3-30]); the vast majority were negative (96.7% of tests and 83.6% of episodes). The incidence of breakthrough invasive aspergillosis was 1.9% (5/262), all with true-positive GM test results. Our study identified 30 false-positive GM evaluable episodes (85.7%; 13.8% of all evaluable episodes), validating with real-life data the low positive predictive value of the assay in this setting (12%). In 26 of these 30 episodes (86.7%), the false-positive result(s) occurred in tests performed as preemptive surveillance only. Conversely, in evaluable cases with positive GM tests and a clinical suspicion of invasive fungal disease, the performance of diagnostic-driven GM tests improved, with a positive predictive value of 89.6%. CONCLUSIONS The low pretest risk of invasive aspergillosis in the context of effective antimold prophylaxis renders serum GM surveillance of asymptomatic patients unreliable, as all results would be either negative or false positive. The test remains useful to diagnose patients with a clinical suspicion of invasive fungal disease, calling for a more efficient copositioning of effective prophylaxis and GM testing in this clinical setting.

Invasive Aspergillosis Complicating Pandemic Influenza A (H1N1) Infection in Severely Immunocompromised Patients

We report 5 cases of invasive aspergillosis occurring in severely immunosuppressed patients hospitalized with pandemic influenza A (H1N1). We suggest that infection with influenza A (H1N1) may predispose immunocompromised patients to develop invasive aspergillosis. Physicians should be aware of this potential association to allow early diagnosis and prompt treatment of aspergillosis.

Clinical efficacy and safety of primary antifungal prophylaxis with posaconazole vs itraconazole in allogeneic blood and marrow transplantation

Posaconazole has been recently approved for primary antifungal prophylaxis in patients with prolonged neutropenia after AML induction chemotherapy and patients with GVHD. We now present the first experience of the efficacy and safety of posaconazole during the early phase of post-allogeneic BMT (n=33; from June 2007), in comparison with itraconazole primary prophylaxis (n=16; up to May 2007). More patients receiving posaconazole were T-cell depleted (P=0.003). Groups were otherwise comparable in terms of age, sex, disease, neutrophil engraftment, incidence of GVHD, use of unrelated donors and type of conditioning. Safety data as well as the incidence of fever (84%) and persistent fever (27%) during the 100-day treatment period were comparable for both antifungal agents. Patients receiving posaconazole had a lower cumulative incidence of proven or probable invasive fungal disease, as defined by the European Organization for Research and Treatment of Cancer criteria (0 vs 12%; P=0.04), which associated with a higher probability of fungal-free survival (91 vs 56%; P=0.003) and an improved probability of OS (91 vs 63%; P=0.011) compared with patients receiving itraconazole. Our single-centre experience suggests that antifungal prophylaxis with posaconazole may lead to a better outcome than itraconazole for patients in the early high-risk neutropenic period after allogeneic BMT.

Bloodstream Infections in Patients With Solid Tumors: Epidemiology, Antibiotic Therapy, and Outcomes in 528 Episodes in a Single Cancer Center

AbstractCurrent information regarding bloodstream infection (BSI) in patients with solid tumors is scarce. We assessed the epidemiology, antibiotic therapy, and outcomes of BSI in these patients. We also compared patients who died with those who survived to identify risk factors associated with mortality. From January 2006 to July 2012 all episodes of BSI in patients with solid tumors at a cancer center were prospectively recorded and analyzed. A total of 528 episodes of BSI were documented in 489 patients. The most frequent neoplasms were hepatobiliary tumors (19%), followed by lung cancer (18%) and lower gastrointestinal malignancies (16%). Many patients had received corticosteroid therapy (41%), and 15% had neutropenia (<500 neutrophils/&mgr;L) at the time of BSI. The most common source of BSI was cholangitis (21%), followed by other abdominal (19.5%) and urinary tract infections (17%). Gram-negative BSI occurred in 55% of cases, mainly due to Escherichia coli (55%), Pseudomonas aeruginosa (18%), and Klebsiella pneumoniae (16%). Among gram-positive BSI (35%), viridans group streptococci were the most frequent causative organisms (22%), followed by Staphylococcus aureus (21%) and Enterococcus species (18%). We identified 61 multidrug-resistant (MDR) organisms (13%), mainly extended-spectrum &bgr;-lactamase-producing Enterobacteriaceae (n = 20) and AmpC-producing Enterobacteriaceae (n = 13). The majority of patients with BSI caused by MDR organisms had received antibiotics (70%), and they had been previously hospitalized (61.4%) more frequently than patients with BSI caused by susceptible strains. Inadequate empirical antibiotic therapy was given to 23% of patients, with a higher proportion in those with BSI due to a MDR strain (69%). Early (<48 h) and overall (30 d) case-fatality rates were 7% and 32%, respectively. The overall case-fatality rate was higher among cases caused by MDR organisms (39.3%). The only independent risk factors for the early case-fatality rate were the endogenous source of BSI (odds ratio [OR], 3.57; 95% confidence interval [CI], 1.06–12.02), shock at presentation (OR, 3.63; 95% CI, 1.63–8.09), and corticosteroid therapy (OR, 3.245; 95% CI, 1.43–7.32). The independent risk factors for overall case-fatality rate were the presence of a chronic advanced cancer (OR, 35.39; 95% CI, 2.48–504.91), shock at presentation (OR, 25.84; 95% CI, 3.73–179.0), and corticosteroid therapy (OR, 6.98; 95% CI, 1.61–30.21).BSI in patients with solid tumors occurred mainly among those with hepatobiliary cancer, and cholangitis was the most frequent source; gram-negative bacilli were the most frequent causative agents. MDR organisms were relatively common, particularly in patients who had previously received antibiotics and had been hospitalized; these patients were frequently treated with inadequate empirical antibiotic therapy and had a poorer outcome. The case-fatality rate of patients with solid tumors and BSI was high and was associated with chronic advanced cancer, corticosteroid therapy, and shock at presentation.

Etiology, clinical features and outcomes of pre-engraftment and post-engraftment bloodstream infection in hematopoietic SCT recipients

We conducted an observational study to assess the etiology, clinical features and outcomes of bloodstream infection (BSI) in 172 hematopoietic SCT (HCST) recipients. One hundred episodes of BSI in the pre-engraftment period (early onset) were compared with 89 episodes in the post-engraftment phase (late onset). More patients with late-onset BSI received an allogeneic HSCT, had GVHD and had received corticosteroids, whereas patients with early-onset BSI were more likely to have neutropenia, severe mucositis and a central venous catheter (CVC) in place. CVC was the most frequent site of infection, followed by an endogenous source. Pneumonia and gastrointestinal infection were particularly frequent in late-onset BSI, whereas mucositis was more frequent in the early-onset group. Gram-positive organisms predominated over Gram negatives. Streptococcus pneumoniae was more frequent in patients with late-onset BSI. Patients with late-onset BSI presented worse outcomes regarding septic shock, intensive care unit admission and early and overall case-fatality rates. Early-onset BSI was mainly related to the presence of neutropenia, mucositis and CVC, whereas late-onset BSI mainly affected severely immunosuppressed allogeneic HSCT recipients with GVHD and corticosteroids. Late-onset BSI caused high case-fatality rates. BSI due to S. pneumoniae was especially frequent late after transplantation. The development of better vaccination strategies is needed.

Bloodstream infections in neutropenic patients with cancer: Differences between patients with haematological malignancies and solid tumours

OBJECTIVES We sought to identify the characteristics, aetiology, antibiotic resistance and outcomes of bloodstream infection (BSI) in neutropenic patients with haematological malignancies (HM) and in those with solid tumours (ST) and assess their impact on empirical therapy and outcomes. METHODS All episodes of BSI in neutropenic patients with HM and ST were prospectively recorded and compared. RESULTS Of 579 episodes of BSI, 493 occurred in patients with HM and 86 in patients with ST. An endogenous source and catheter-related infection were more frequent in patients with HM, whereas pneumonia and urinary tract were more common in the ST group. BSI was mainly due to Gram-negative bacilli. Coagulase-negative staphylococci were more frequent in patients with HM, while Pseudomonas aeruginosa was more common in patients with ST and was the leading cause of pneumonia. Multidrug-resistant Gram-negative bacilli (MDRGNB) were more frequently isolated in haematological patients who more often received inadequate empirical therapy than those with ST. Case-fatality rates were higher in patients with ST. CONCLUSIONS We identified significant differences in BSI in neutropenic patients with HM and ST. MDRGNB were more often isolated in patients with HM. Pneumonia due to P. aeruginosa was particularly frequent among patients with ST. Case-fatality rates were higher in patients with ST.

Diagnosis and antimicrobial treatment of invasive infections due to multidrug-resistant Enterobacteriaceae. Guidelines of the Spanish Society of Infectious Diseases and Clinical Microbiology

The spread of multidrug-resistant Enterobacteriaceae related to the production of extended-spectrum β-lactamases and carbapenemases is a serious public health problem worldwide. Microbiological diagnosis and therapy of these infections are challenging and controversial. Clinically relevant questions were selected and the literature was reviewed for each of them. The information from the selected articles was extracted and recommendations were provided and graded according to the strength of the recommendations and quality of the evidence. The document was opened to comments from the members from the Spanish Society of Infectious Diseases and Clinical Microbiology, which were considered for inclusion in the final version. Evidence-based recommendations are provided for the use of microbiological techniques for the detection of extended-spectrum β-lactamases and carbapenemases in Enterobacteriaceae, and for antibiotic therapy for invasive/severe infections caused by these organisms. The absence of randomised controlled trials is noteworthy; thus, recommendations are mainly based on observational studies (that have important methodological limitations), pharmacokinetic and pharmacodynamics models, and data from animal studies. Additionally, areas for future research were identified.

Increase in Bloodstream Infection Due to Vancomycin-Susceptible Enterococcus faecium in Cancer Patients: Risk Factors, Molecular Epidemiology and Outcomes

We conducted a prospective study to assess the risk factors, molecular epidemiology and outcome of bloodstream infection (BSI) due to Enterococcus faecium in hospitalized cancer patients. Between 2006 and 2012, a significant increase in vancomycin-susceptible E. faecium BSI was observed among cancer patients. Comparison of 54 episodes of BSI due to E. faecium with 38 episodes of BSI due to E. faecalis showed that previous use of carbapenems was the only independent risk factor for E. faecium acquisition (OR 10.24; 95% CI, 1.35-77.66). All E. faecium isolates were susceptible to glycopeptides, whereas 97% showed high-level resistance to ampicillin and ciprofloxacin. All 30 isolates available for genotyping belonged to the hospital-associated E. faecium lineages 17, 18 and 78. After 2009, most of the isolates belonged to ST117 (lineage 78). Patients with E. faecium BSI were more likely to receive inadequate initial empirical antibiotic therapy than patients with E. faecalis BSI, and time to adequate empirical antibiotic therapy was also longer in the former group. No significant differences were found between the two groups regarding early and overall case-fatality rates. Independent risk factors for overall case-fatality were current corticosteroids (OR 4.18; 95% CI, 1.34-13.01) and intensive care unit admission (OR 9.97; 95% CI, 1.96-50.63). The emergence of E. faecium among cancer patients is a concern since there are limited treatment options and it may presage the emergence of vancomycin-resistant enterococci. A rationale approach that combines infection control with antimicrobial stewardship.