Bloodstream infections in patients with solid tumors: epidemiology, antibiotic therapy, and outcomes in 528 episodes in a single cancer center

Increasing Antimicrobial Resistance Monitored in Surveillance Analysis of Blood Stream Infections in Febrile Neutropenic Pediatric Oncology Patients

BACKGROUND

Continuous surveillance of pattern of blood stream infection is necessary in febrile neutropenia (FN)especially with the recent escalating trend in the management of pediatric cancer patients towards intensified regimens and with the increase in infections caused by resistant organisms limiting the choice of antibiotics.

AIM

To monitor change in pattern of blood stream infections (BSI) in FN pediatric cancer patients.

MATERIALS AND METHODS

Surveillance of FN episodes with positive BSI was prospectively monitored and compared to a previous surveillance in the same pediatric oncology unit.

RESULTS

A total of 232 BSI positive episodes were documented in 192 patients during a 6 months period. The results of recent surveillance analysis showed an increase in intensified regimens of chemotherapy, antimicrobial resistance, fungal infections, and prolonged duration of episodes when compared to previous surveillance, with p value sof <0.001, 0.005, 0.021, and <0.001, respectively. There was an apparent decrease in the crude mortality but this was not statistically significant, to 6% in 2011 from 10 % in 2006.

CONCLUSIONS

The pattern of BSI at our institution is still inclining towards gram positive organisms but is showing a shift towards more antibiotic resistance and fungal infections.

Prospective Evaluation of Infection Episodes in Cancer Patients in a Tertiary Care Academic Center: Microbiological Features and Risk Factors for Mortality

OBJECTIVE

We aimed to determine the frequency, type, and etiology of infections and the risk factors for infections and mortality in hospitalized cancer patients.

MATERIALS AND METHODS

We prospectively enrolled adult cancer patients hospitalized in the internal medicine wards of a tertiary care academic center between January and August 2004. Patients were followed during their hospitalization periods for neutropenia, infections, culture results, and mortality.

RESULTS

We followed 473 cancer patients with 818 hospitalization episodes and 384 infection episodes in total. Seventy-nine percent of the infections were nosocomial, and febrile neutropenia (FN) was observed in 196 (51%) of the infection episodes. Bacteremia was found in 29% of FN episodes and in 8% of nonneutropenic patients. Gram-positive bacteria were the leading cause of bacteremia in both neutropenic and nonneutropenic cases (70% and 58%, respectively). Presence of an indwelling central catheter increased bacteremia risk by 3-fold. The overall mortality rate was 17%, whereas 34% of the patients with bloodstream infections died. Presence of bacteremia and advanced disease stage increased overall mortality by 6.1-fold and 3.7-fold, respectively.

CONCLUSION

Nearly half of the cancer patients developed an infection during their hospital stays, with gram-positive bacteria being the predominant etiologic microorganisms. This demonstrates the changing trends in infections considering that, until 2004, gram-negative bacteria were the most predominant microorganisms among cancer patients in our institute.

Bloodstream infections in patients with solid tumors

Little information is currently available regarding bloodstream infection (BSI) in patients with solid tumors who, for a variety of reasons, are particularly predisposed to develop this condition. In this review we focus on the incidence, epidemiology, clinical features, etiology, antimicrobial resistance, and outcomes of BSI of adult cancer patients with solid tumors. Most episodes of BSI occur in non-neutropenic patients, in whom the site of primary or metastatic tumor often serves as the portal of entry. The urinary tract and the abdomen are the most frequent sources of infection, and cholangitis is the most common recurrent source of BSI. Gram-negative bacilli are becoming the leading cause of BSI in patients with solid tumors, and the rate of multidrug resistance is increasingly being recognized. The case-fatality rate in patients with solid tumors and BSI is high, especially among those with comorbidities, advanced neoplasms, corticosteroid therapy, and shock at presentation.

Bloodstream infections in internal medicine

Bloodstream infections (BSI) carry a heavy burden of morbidity and mortality in modern internal medicine wards (IMW). These wards are often filled with elderly subjects with several risk factors for BSI, such as multiple comorbidities, polypharmacy, immunosuppression, and indwelling devices. Diagnosing BSI in such a setting might require a high degree of suspicion, since the clinical presentation could be affected by underlying conditions and concomitant medications, which might delay the administration of an appropriate antimicrobial therapy, an event strongly and unfavorably influencing survival. Furthermore, selecting the appropriate antimicrobial therapy to treat these patients is becoming an increasingly complex task in which all possible benefits and costs should be carefully analyzed from patient and public health perspectives. Only a specialized, continuous, and interdisciplinary approach could really improve the management of IMW patients in an era of increasing antimicrobial resistance and complexity of care.

Management of infection and febrile neutropenia in patients with solid cancer

An expert group from the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC, for its acronym in Spanish) and the Spanish Society of Medical Oncology (SEOM, for its acronym in Spanish) have reviewed the main aspects to be considered when evaluating patients with solid cancer and infectious complications contained in this article. Recommendations have, therefore, been put forth regarding the prophylaxis of the most prevalent infections in these patients, the use of vaccines, measures to control infection through vascular catheters, and preventing infection in light of certain surgical maneuvers. The following is a revision of the criteria for febrile neutropenia management and the use of colony-stimulating factors and closes with several guidelines for treating the cancer patient with serious infection. The document concludes with a series of measures to control hospital infection.

Pseudomonas aeruginosa: arsenal of resistance mechanisms, decades of changing resistance profiles, and future antimicrobial therapies

Antimicrobial resistance is one of the most serious public health issues facing humans since the discovery of antimicrobial agents. The frequent, prolonged, and uncontrolled use of antimicrobial agents are major factors in the emergence of antimicrobial-resistant bacterial strains, including multidrug-resistant variants. Pseudomonas aeruginosa is a leading cause of nosocomial infections. The abundant data on the increased resistance to antipseudomonal agents support the need for global action. There is a paucity of new classes of antibiotics active against P. aeruginosa. Here, we discuss recent antibacterial resistance profiles and mechanisms of resistance by P. aeruginosa. We also review future potential methods for controlling antibiotic-resistant bacteria, such as phage therapy, nanotechnology and antipseudomonal vaccines.

Port type is a possible risk factor for implantable venous access port-related bloodstream infections and no sign of local infection predicts the growth of gram-negative bacilli

BACKGROUND

Implantable venous access port (IVAP)-related blood stream infections (BSIs) are one of the most common complications of implantable venous ports. The risk factors and pathogens for IVAP-related BSIs are still controversial.

METHODS

We retrospectively reviewed all patients who received IVAPs at a Hospital in Taiwan from January 1, 2011 to June 31, 2014. Two types of venous port, BardPort® 6.6 fr (Bard port) and Autosuture Chemosite® 7.5 fr (TYCO port) were used. All patients with clinically proven venous port-related BSIs were enrolled.

RESULTS

A total of 552 patients were enrolled. There were 34 episodes of IVAP-related BSIs during the study period for a total incidence of 0.177 events/1000 catheter days. Port type (TYCO vs. Bard, HR = 7.105 (95% confidence interval (CI), 1.688-29.904), p = 0.0075), age > 65 years (HR = 2.320 (95 % CI, 1.179-4.564), p = 0.0148), and lung cancer (HR = 5.807 (95% CI, 2.946-11.447), p < 0.001) were risk factors for port infections. We also found that no local sign of infection was significantly associated with the growth of gram-negative bacilli (p = 0.031).

CONCLUSIONS

TYCO venous ports, age > 65 years, and lung cancer were all significant risk factors for IVAP-related BSIs, and no sign of infection was significantly associated with the growth of gram-negative bacilli.

Local bacteria affect the efficacy of chemotherapeutic drugs

In this study, the potential effects of bacteria on the efficacy of frequently used chemotherapies was examined. Bacteria and cancer cell lines were examined in vitro and in vivo for changes in the efficacy of cancer cell killing mediated by chemotherapeutic agents. Of 30 drugs examined in vitro, the efficacy of 10 was found to be significantly inhibited by certain bacteria, while the same bacteria improved the efficacy of six others. HPLC and mass spectrometry analyses of sample drugs (gemcitabine, fludarabine, cladribine, CB1954) demonstrated modification of drug chemical structure. The chemoresistance or increased cytotoxicity observed in vitro with sample drugs (gemcitabine and CB1954) was replicated in in vivo murine subcutaneous tumour models. These findings suggest that bacterial presence in the body due to systemic or local infection may influence tumour responses or off-target toxicity during chemotherapy.

Management of Infection and Febrile Neutropenia in Patients with Solid Cancer

A group of experts from the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC) and the Spanish Society of Medical Oncology (SEOM) have reviewed in this paper the main aspects to be considered in the evaluation of patients with solid cancer and infectious diseases. They have established a series of recommendations on the prevention of the most prevalent infections in these patients, the use of vaccines, the control measures of vascular catheter infection and prevention of infections before certain surgical procedures. Also the criteria for management of febrile neutropenia and the use of colony-stimulating factors were revised. Finally they provide a series of recommendations for the treatment of cancer patients with severe infection. The document is completed with a series of measures for the control of hospital infection.

Vaccine protection of leukopenic mice against Staphylococcus aureus bloodstream infection

The risk for Staphylococcus aureus bloodstream infection (BSI) is increased in immunocompromised individuals, including patients with hematologic malignancy and/or chemotherapy. Due to the emergence of antibiotic-resistant strains, designated methicillin-resistant S. aureus (MRSA), staphylococcal BSI in cancer patients is associated with high mortality; however, neither a protective vaccine nor pathogen-specific immunotherapy is currently available. Here, we modeled staphylococcal BSI in leukopenic CD-1 mice that had been treated with cyclophosphamide, a drug for leukemia and lymphoma patients. Cyclophosphamide-treated mice were highly sensitive to S. aureus BSI and developed infectious lesions lacking immune cell infiltrates. Virulence factors of S. aureus that are key for disease establishment in immunocompetent hosts-α-hemolysin (Hla), iron-regulated surface determinants (IsdA and IsdB), coagulase (Coa), and von Willebrand factor binding protein (vWbp)-are dispensable for the pathogenesis of BSI in leukopenic mice. In contrast, sortase A mutants, which cannot assemble surface proteins, display delayed time to death and increased survival in this model. A vaccine with four surface antigens (ClfA, FnBPB, SdrD, and SpAKKAA), which was identified by genetic vaccinology using sortase A mutants, raised antigen-specific immune responses that protected leukopenic mice against staphylococcal BSI.