The epidemiology and treatment of infections in cancer patients

The Significance of Microenvironmental and Circulating Lactate in Breast Cancer

Lactate represents the main product of pyruvate reduction catalyzed by the lactic dehydrogenase family of enzymes. Cancer cells utilize great quantities of glucose, shifting toward a glycolytic metabolism. With the contribution of tumor stromal cells and under hypoxic conditions, this leads toward the acidification of the extracellular matrix. The ability to shift between different metabolic pathways is a characteristic of breast cancer cells and is associated with an aggressive phenotype. Furthermore, the preliminary scientific evidence concerning the levels of circulating lactate in breast cancer points toward a correlation between hyperlactacidemia and poor prognosis, even though no clear linkage has been demonstrated. Overall, lactate may represent a promising metabolic target that needs to be investigated in breast cancer.

A novel risk classifier to predict the in-hospital death risk of nosocomial infections in elderly cancer patients

Background

Elderly cancer patients are more predisposed to developing nosocomial infections during anti-neoplastic treatment, and are associated with a bleaker prognosis. This study aimed to develop a novel risk classifier to predict the in-hospital death risk of nosocomial infections in this population.

Methods

Retrospective clinical data were collected from a National Cancer Regional Center in Northwest China. The Least Absolute Shrinkage and Selection Operator (LASSO) algorithm was utilized to filter the optimal variables for model development and avoid model overfitting. Logistic regression analysis was performed to identify the independent predictors of the in-hospital death risk. A nomogram was then developed to predict the in-hospital death risk of each participant. The performance of the nomogram was evaluated using receiver operating characteristics (ROC) curve, calibration curve, and decision curve analysis (DCA).

Results

A total of 569 elderly cancer patients were included in this study, and the estimated in-hospital mortality rate was 13.9%. The results of multivariate logistic regression analysis showed that ECOG-PS (odds ratio [OR]: 4.41, 95% confidence interval [CI]: 1.95-9.99), surgery type (OR: 0.18, 95%CI: 0.04-0.85), septic shock (OR: 5.92, 95%CI: 2.43-14.44), length of antibiotics treatment (OR: 0.21, 95%CI: 0.09-0.50), and prognostic nutritional index (PNI) (OR: 0.14, 95%CI: 0.06-0.33) were independent predictors of the in-hospital death risk of nosocomial infections in elderly cancer patients. A nomogram was then constructed to achieve personalized in-hospital death risk prediction. ROC curves yield excellent discrimination ability in the training (area under the curve [AUC]=0.882) and validation (AUC=0.825) cohorts. Additionally, the nomogram showed good calibration ability and net clinical benefit in both cohorts.

Conclusion

Nosocomial infections are a common and potentially fatal complication in elderly cancer patients. Clinical characteristics and infection types can vary among different age groups. The risk classifier developed in this study could accurately predict the in-hospital death risk for these patients, providing an important tool for personalized risk assessment and clinical decision-making.

Updated Understanding of the Causes of Cancer, and a New Theoretical Perspective of Combinational Cancer Therapies, a Hypothesis

We present an integrative understanding of cancer as a metabolic multifactorial, multistage disease. We focus on underlying genetics-environmental interactions, evidenced by telomere changes. A range of genetic and epigenetic factors, including physical agents and predisposing factors such as diet and lifestyle are included. We present a structured model of the causes of cancer, methods of investigations, approaches to cancer prevention, and polypharmaceutical multidisciplinary complex treatment within a framework of personalized medicine. We searched PubMed, National Cancer Institute online, and other databases for publications regarding causes of cancer, reports of novel mitochondrial reprogramming, epigenetic, and telomerase therapies and state-of-the-art investigations. We focused on multistep treatment protocols to enhance early detection of cancer, and elimination or neutralization of the causes and factors associated with cancer formation and progression.Our aim is to suggest a model therapeutic protocol that incorporates the patient's genome, metabolism, and immune system status; stage of tumor development; and comorbidity(ies), if any. Investigation and treatment of cancer is a challenge that requires further holistic studies that improve the quality of life and survival rates, but are most likely to aid prevention.

Toll-Like Receptor 2 at the Crossroad between Cancer Cells, the Immune System, and the Microbiota

Toll-like receptor 2 (TLR2) expressed on myeloid cells mediates the recognition of harmful molecules belonging to invading pathogens or host damaged tissues, leading to inflammation. For this ability to activate immune responses, TLR2 has been considered a player in anti-cancer immunity. Therefore, TLR2 agonists have been used as adjuvants for anti-cancer immunotherapies. However, TLR2 is also expressed on neoplastic cells from different malignancies and promotes their proliferation through activation of the myeloid differentiation primary response protein 88 (MyD88)/nuclear factor kappa-light-chain-enhancer of activated B cell (NF-κB) pathway. Furthermore, its activation on regulatory immune cells may contribute to the generation of an immunosuppressive microenvironment and of the pre-metastatic niche, promoting cancer progression. Thus, TLR2 represents a double-edge sword, whose role in cancer needs to be carefully understood for the setup of effective therapies. In this review, we discuss the divergent effects induced by TLR2 activation in different immune cell populations, cancer cells, and cancer stem cells. Moreover, we analyze the stimuli that lead to its activation in the tumor microenvironment, addressing the role of danger, pathogen, and microbiota-associated molecular patterns and their modulation during cancer treatments. This information will contribute to the scientific debate on the use of TLR2 agonists or antagonists in cancer treatment and pave the way for new therapeutic avenues.

SARS-CoV-2 pathophysiology and its clinical implications: An integrative overview of the pharmacotherapeutic management of COVID-19

Common manifestations of COVID-19 are respiratory and can extend from mild symptoms to severe acute respiratory distress. The severity of the illness can also extend from mild disease to life-threatening acute respiratory distress syndrome (ARDS). SARS-CoV-2 infection can also affect the gastrointestinal tract, liver and pancreatic functions, leading to gastrointestinal symptoms. Moreover, SARS-CoV-2 can cause central and peripheral neurological manifestations, affect the cardiovascular system and promote renal dysfunction. Epidemiological data have indicated that cancer patients are at a higher risk of contracting the SARS-CoV-2 virus. Considering the multitude of clinical symptoms of COVID-19, the objective of the present review was to summarize their pathophysiology in previously healthy patients, as well as in those with comorbidities. The present review summarizes the current, though admittedly fluid knowledge on the pathophysiology and symptoms of COVID-19 infection. Although unclear issues still remain, the present study contributes to a more complete understanding of the disease, and may drive the direction of new research. The recognition of the severity of the clinical symptoms of COVID-19 is crucial for the specific therapeutic management of affected patients.

Bloodstream Infections With a Novel Nontuberculous Mycobacterium Involving 52 Outpatient Oncology Clinic Patients-Arkansas, 2018

BACKGROUND

In July 2018, the Arkansas Department of Health (ADH) was notified by hospital A of 3 patients with bloodstream infections (BSIs) with a rapidly growing nontuberculous Mycobacterium (NTM) species; on 5 September 2018, 6 additional BSIs were reported. All were among oncology patients at clinic A. We investigated to identify sources and to prevent further infections.

METHODS

ADH performed an onsite investigation at clinic A on 7 September 2018 and reviewed patient charts, obtained environmental samples, and cultured isolates. The isolates were sequenced (whole genome, 16S, rpoB) by the Centers for Disease Control and Prevention to determine species identity and relatedness.

RESULTS

By 31 December 2018, 52 of 151 (34%) oncology patients with chemotherapy ports accessed at clinic A during 22 March-12 September 2018 had NTM BSIs. Infected patients received significantly more saline flushes than uninfected patients (P < .001) during the risk period. NTM grew from 6 unused saline flushes compounded by clinic A. The identified species was novel and designated Mycobacterium FVL 201832. Isolates from patients and saline flushes were highly related by whole-genome sequencing, indicating a common source. Clinic A changed to prefilled saline flushes on 12 September as recommended.

CONCLUSIONS

Mycobacterium FVL 201832 caused BSIs in oncology clinic patients. Laboratory data allowed investigators to rapidly link infections to contaminated saline flushes; cooperation between multiple institutions resulted in timely outbreak resolution. New state policies being considered because of this outbreak include adding extrapulmonary NTM to ADH's reportable disease list and providing more oversight to outpatient oncology clinics.

Bacterial Etiology of Wound Exudates in Tertiary Care Cancer Patients and Antibiogram of the Isolates

Introduction:

Patients with malignancies frequently develop infections as a result of surgical procedures and fungating wounds leading to pus formation. This cross-sectional study was conducted to explore the bacteriological spectra of infections of various cancer sites and their antibiotic sensitivity patterns among the patients visiting minor operation theatre (OT) of B.P. Koirala Memorial Cancer Hospital (BPKMCH), Chitwan, Nepal.

Methods:

Over a period of 3 months from September to November 2018, a total of 183 wound exudates and pus samples were collected and analyzed by standard microbiological procedures. Isolates were identified based on the colony characters, Gram staining and an array of biochemical tests. Antibiotic susceptibility testing was performed by Kirby-Bauer disc diffusion technique according to criteria set by CLSI, 2016. Methicillin resistance in Staphylococcus aureus was tested with the help of cefoxitin using disc diffusion method.

Results:

Out of the 183 samples, 149 (81.4%) were culture positive. Among 13 different isolates identified, S. aureus (43.0%) was predominant followed by E. coli (14.0%). Higher incidence of bacteria was seen among the males (52.3%), in the age group 51 to 60 years (26.8%) and among the patients undergoing surgical intervention to deal with cancer (34.2%). The prevalence of wound infection was significantly affected by gender, age, and treatment regimen (P < .01). Out of the total 68 S. aureus isolates, 38 (44.1%) were deemed as Methicillin-resistant Staphylococcus aureus (MRSA). Among the 158 isolates, 85 (53.8%) were multi-drug resistant (MDR). Cefepime was the most effective antibiotic for Gram positive isolates whereas both imipenem and meropenem were found to be equally more effective for Gram negative isolates.

Conclusion:

This study suggests that patients with malignancies harbor pathogenic bacteria; therefore, prudent use of antibiotics is essential to prevent the emergence of MDR pathogens.

The relationship between mortality and microbiological parameters in febrile neutropenic patients with hematological malignancies

Objectives:

To determine effective risk factors on mortality in febrile neutropenic cases with hematologic malignancy. Patients with hematologic diseases are more prone to infections and those are frequent causes of mortality.

Methods:

This retrospective study was performed using data of 164 febrile neutropenic cases with hematologic malignancies who were followed up in a hematology clinic of a tertiary health care center between 2011-2015. The relationship between descriptive and clinical parameters rates and rates of mortality on the 7^th and the 21^st days were investigated.

Results:

Patients with absolute neutrophil count<100/mm³, duration of neutropenia longer than 7 days, pneumonia or gastrointestinal foci of infection, central catheterization (p=0.025), isolation of Gram (-) bacteria in culture, carbapenem resistance, septic shock, and bacterial growth during intravenous administration of antibiotic treatment were under more risk for mortality on both the 7^th and the 21^st days. The final multivariate logistic regression results showed that pneumonia (p<0.0001), septic shock (p=0.004) and isolation of Gram-negative bacteria (p=0.032) were statistically significant risk factors.

Conclusion:

Early diagnosis and appropriate treatment of serious infections, which are important causes of morbidity and mortality, are crucial in patients with febrile neutropenia. Thus, each center should closely follow up causes of infection and establish their empirical antibiotherapy protocols to accomplish better results in the management of febrile neutropenia.

Bacterial profile, antibiotic resistance pattern and associated factors among cancer patients at University of Gondar Hospital, Northwest Ethiopia

INTRODUCTION

Cancer is alarmingly increased in developing countries like Ethiopia, where multidrug resistant bacterial infection is rampant. The aim of this study was to determine the bacterial profile, antimicrobial resistance pattern, and associated factors among cancer patients attending University of Gondar Hospital.

METHODS

A consecutive 216 cancer patients were recruited from February to April, 2017. Socio-demographic and clinical data were collected using a structured questionnaire. Culture and antibiotic resistance were done following standard microbiological procedures.

RESULT

The overall prevalence of bacterial infection was 19.4%. The predominant bacterial isolates were Staphylococcus aureus (28.6%), followed by coagulase negative staphylococci (26.2%) and Escherichia coli (21.4%). Multidrug resistance was detected in 46.5% bacterial isolates. Methicillin resistance was detected in 25% of S. aureus and in 45.5% of coagulase negative staphylococci. Fluoroquinolone resistance was detected in 33.3% of E. coli isolates. Cancer patients with solid tumor, started cancer therapy, and being symptomatic had higher odds of culture positivity.

CONCLUSION

The overall burden of bacterial infection among cancer patients is considerably high. The findings of this study inform baseline information for policymakers and call for additional studies with large isolates in different cancer treatment centers in the region and in the country to better understand the bacterial isolate and resistance pattern.

Commonly Used Oncology Drugs Decrease Antifungal Effectiveness against Candida and Aspergillus Species

The incidence of invasive fungal infections has risen significantly in recent decades as medical interventions have become increasingly aggressive. These infections are extremely difficult to treat due to the extremely limited repertoire of systemic antifungals, the development of drug resistance, and the extent to which the patient's immune function is compromised. Even when the appropriate antifungal therapies are administered in a timely fashion, treatment failure is common, even in the absence of in vitro microbial resistance. In this study, we screened a small collection of FDA-approved oncolytic agents for compounds that impact the efficacy of the two most widely used classes of systemic antifungals against Candida albicans, Candida glabrata, and Aspergillus fumigatus We have identified several drugs that enhance fungal growth in the presence of azole antifungals and examine the potential that these drugs directly affect fungal fitness, specifically antifungal susceptibility, and may be contributing to clinical treatment failure.

Cost of Cancer-Related Neutropenia or Fever Hospitalizations, United States, 2012

PURPOSE

Neutropenia and subsequent infections are life-threatening treatment-related toxicities of chemotherapy. Among patients with cancer, hospitalizations related to neutropenic complications result in substantial medical costs, morbidity, and mortality. Previous estimates for the cost of cancer-related neutropenia hospitalizations are based on older and limited data. This study provides nationally representative estimates of the cost of cancer-related neutropenia hospitalizations.

METHODS

We examined data from the 2012 National Inpatient Sample and Kids' Inpatient Database. Hospitalizations for cancer-related neutropenia were defined as those with a primary or secondary diagnosis of cancer and a diagnosis of neutropenia or a fever of unknown origin. We examined characteristics of cancer-related neutropenia hospitalizations among children (age < 18 years) and adults (age ≥ 18 years). Adjusted predicted margins were used to estimate length of stay and cost per stay.

RESULTS

There were 91,560 and 16,859 cancer-related neutropenia hospitalizations among adults and children, respectively. Total cost of cancer-related neutropenia hospitalizations was $2.3 billion for adults and $439 million for children. Cancer-related neutropenia hospitalizations accounted for 5.2% of all cancer-related hospitalizations and 8.3% of all cancer-related hospitalization costs. For adults, the mean length of stay for cancer-related neutropenia hospitalizations was 9.6 days, with a mean hospital cost of $24,770 per stay. For children, the mean length of stay for cancer-related neutropenia hospitalizations was 8.5 days, with a mean hospital cost of $26,000 per stay.

CONCLUSION

We found the costs of cancer-related neutropenia hospitalizations to be substantially high. Efforts to prevent and minimize neutropenia-related complications among patients with cancer may decrease hospitalizations and associated costs.

Risk factors for community-acquired bacterial meningitis

BACKGROUND

Bacterial meningitis is a significant burden of disease and mortality in all age groups worldwide despite the development of effective conjugated vaccines. The pathogenesis of bacterial meningitis is based on complex and incompletely understood host-pathogen interactions. Some of these are pathogen-specific, while some are shared between different bacteria.

METHODS

We searched the database PubMed to identify host risk factors for bacterial meningitis caused by the pathogens Streptococcus pneumoniae, Neisseria meningitidis and Haemophilus influenzae type b, because they are three most common causative bacteria beyond the neonatal period.

RESULTS

We describe a number of risk factors; including socioeconomic factors, age, genetic variation of the host and underlying medical conditions associated with increased susceptibility to invasive bacterial infections in both children and adults.

CONCLUSIONS

As conjugated vaccines are available for these infections, it is of utmost importance to identify high risk patients to be able to prevent invasive disease.

Outcomes of high-grade gastrointestinal graft-versus-host disease posthematopoietic stem cell transplantation in children

We explored the clinical course of acute high-grade gastrointestinal graft-versus-host disease in children in a single center. This was a retrospective analysis of 28 pediatric patients who presented with a clinical diagnosis of stage III and IV acute graft-versus-host disease (aGVHD) of the gastrointestinal system (GIS). Generally, skin involvement was the initial manifestation of aGVHD that began in the first 3 weeks of hematopoietic stem cell transplantation (HSCT); on the other hand, GIS involvement predominated after the second week of HSCT. Reported adult data show a survival rate of only 25%; however, our study showed more favorable outcomes in children with a survival rate of 55%. We monitored levels of albumin and immunoglobulin G and observed low levels overall during treatment of unresponsive patients, although only albumin levels were shown to be significantly different. We observed a significant increase in mortality with the use of antithymocyte globulin in GIS aGVHD, although antithymocyte globulin used for graft-versus-host disease prophylaxis had no demonstrable effect on GIS aGVHD mortality. Whether the significantly lower GIS aGVHD mortality among the children recruited in our study than among their historical adult counterparts is a primary result of the specific attributes of the pediatric GIS, or whether it originated from HSCT kinetics remains to be determined by future studies.

Causative Organisms and Associated Antimicrobial Resistance in Healthcare-Associated, Central Line-Associated Bloodstream Infections From Oncology Settings, 2009-2012

BACKGROUND

Recent antimicrobial resistance data are lacking from inpatient oncology settings to guide infection prophylaxis and treatment recommendations. We describe central line-associated bloodstream infection (CLABSI) pathogens and antimicrobial resistance patterns reported from oncology locations to the Centers for Disease Control and Prevention's National Healthcare Safety Network (NHSN).

METHODS

CLABSI data reported to NHSN from 2009 to 2012 from adult inpatient oncology locations were compared to data from nononcology adult locations within the same hospitals. Pathogen profile, antimicrobial resistance rates, and CLABSI incidence rates per 1000 central line-days were calculated. CLABSI incidence rates were compared using Poisson regression.

RESULTS

During 2009-2012, 4654 CLABSIs were reported to NHSN from 299 adult oncology units. The most common organisms causing CLABSI in oncology locations were coagulase-negative staphylococci (16.9%), Escherichia coli (11.8%), and Enterococcus faecium (11.4%). Fluoroquinolone resistance was more common among E. coli CLABSI in oncology than nononcology locations (56.5% vs 41.5% of isolates tested; P < .0001) and increased significantly from 2009-2010 to 2011-2012 (49.5% vs 60.4%; P = .01). Furthermore, rates of CLABSI were significantly higher in oncology compared to nononcology locations for fluoroquinolone-resistant E. coli (rate ratio, 7.37; 95% confidence interval [CI], 6.20-8.76) and vancomycin-resistant E. faecium (rate ratio, 2.27, 95% CI, 2.03-2.53). However, resistance rates for some organisms, such as Klebsiella species and Pseudomonas aeruginosa, were lower in oncology than in nononcology locations.

CONCLUSIONS

Antimicrobial-resistant E. coli and E. faecium have become significant pathogens in oncology. Practices for antimicrobial prophylaxis and empiric antimicrobial therapy should be regularly assessed in conjunction with contemporary antimicrobial resistance data.

The rapid response team in outpatient settings identifies patients who need immediate intensive care unit admission: A call for policy maker

Background:

Caregivers in the ambulatory care setting with differing clinical background could encounter a patient at high risk of deterioration. In the absence of a dedicated acute care team, the response to an unanticipated medical emergencies in these settings is likely to have a poor outcome.

Objective:

To describe our experience in implementing an intensivist-led rapid response team (RRT) in the outpatient settings that identified patients who needed immediate Intensive Care Unit (ICU) admission. The effect on in hospital arrests, mortality, and ICU outcome is not the scope of this study.

Materials and Methods:

This retrospective descriptive study was performed from January 1, 2009 to December 31, 2011 in a tertiary hospital. Data from hospital records were used (none from patients’ records). Consent was not needed.

Measurements:

Direct ICU admissions from the outpatient areas.

Results:

There were 90 patients cared for by RRT in the outpatient's settings, 76 adult, and 14 pediatric patients. A total of12 adult patients were transferred directly to ICU. Among the patient who were transferred to the emergency department, additional four patients required to be transferred to ICU (total 16 patients [17.7%], 15 adult, and one pediatric patient). Follow-up at 24 h in the ICU showed death of one adult oncology patient (6.25%), and discharge of two patients (12.5%). Nine patients (81%) were still sick to require longer ICU stay.

Conclusion:

Intensivist-led RRT in outpatient settings identifies patients who are critically ill and in need of immediate ICU admission. Thus, an intensivist-led RRT policy in the outpatient settings needs to be implemented hospital wide.

2-fluoro-RNA oligonucleotide CD40 targeted aptamers for the control of B lymphoma and bone-marrow aplasia

Recent studies have underscored the importance of immunomodulatory antibodies in the treatment of solid and hematological tumors. ODN-Aptamers are rising as a novel class of drugs that can rival therapeutic antibodies. The success of some of the current cancer immunotherapy approaches in oncological patients depends on the intrinsic antigenicity of each tumor as has recently been disclosed, and it is hampered in those patients that are treated with myeloablative chemotherapy or radiotherapy, which induce profound immunosuppression. CD40 agonist and antagonist molecules offer a new therapeutic alternative which has the potential to generate anticancer effects by different mechanisms. HS-SELEX was performed to identify high-affinity aptamers against CD40, and three therapeutic CD40 constructs were engineered as: CD40 agonist aptamer, CD40 antagonist aptamer and CD40 agonistic aptamer-shRNA chimera. It is shown that CD40 agonist aptamers can be used to promote bone-marrow aplasia recovery. CD40 antagonist aptamers are revealed to have a direct antitumor effect on CD40-expressing B-cell lymphoma in vitro and in vivo. Further, in order to identify a therapeutic reagent that will generate the optimal conditions for cancer immunotherapy (antigen-presenting cell activation, tumor antigenicity enhancement and bone-marrow aplasia recovery), CD40 agonist aptamer-shRNA chimera was generated to target the inhibition of the Nonsense mRNA Mediated Decay (NMD) to tumor cells.

Outbreak of Tsukamurella species bloodstream infection among patients at an oncology clinic, West Virginia, 2011-2012

OBJECTIVE

To determine the source and identify control measures of an outbreak of Tsukamurella species bloodstream infections at an outpatient oncology facility.

DESIGN

Epidemiologic investigation of the outbreak with a case-control study.

METHODS

A case was an infection in which Tsukamurella species was isolated from a blood or catheter tip culture during the period January 2011 through June 2012 from a patient of the oncology clinic. Laboratory records of area hospitals and patient charts were reviewed. A case-control study was conducted among clinic patients to identify risk factors for Tsukamurella species bloodstream infection. Clinic staff were interviewed, and infection control practices were assessed.

RESULTS

Fifteen cases of Tsukamurella (Tsukamurella pulmonis or Tsukamurella tyrosinosolvens) bloodstream infection were identified, all in patients with underlying malignancy and indwelling central lines. The median age of case patients was 68 years; 47% were male. The only significant risk factor for infection was receipt of saline flush from the clinic during the period September-October 2011 (P = .03), when the clinic had been preparing saline flush from a common-source bag of saline. Other infection control deficiencies that were identified at the clinic included suboptimal procedures for central line access and preparation of chemotherapy.

CONCLUSION

Although multiple infection control lapses were identified, the outbreak was likely caused by improper preparation of saline flush syringes by the clinic. The outbreak demonstrates that bloodstream infections among oncology patients can result from improper infection control practices and highlights the critical need for increased attention to and oversight of infection control in outpatient oncology settings.

Infections After High-Dose Chemotherapy and Autologous Hematopoietic Stem Cell Transplantation

Infection represents an important cause of morbidity after autologous hematopoietic stem cell transplantation (HSCT). Immunodeficiency is the key risk factor and results from interplay between the underlying disease and its therapy. Various defects in the immune system coexist in HSCT recipients. In the early post-transplant period, neutropenia, oral and gastrointestinal mucositis, and the presence of central venous catheters are the main risk factors. Bacterial infections predominate, and the agents and antibiotic susceptibility profiles vary widely in different regions. Invasive candidiasis is infrequent with fluconazole use, but the incidence of invasive aspergillosis is on the rise, mainly in patients receiving purine analogues or intensive chemotherapy before transplant. In the post-engraftment period, infections are less frequent, but may contribute to significant non-relapse mortality. The dynamics of immune reconstitution drives the risk for infection in this period. The most frequent infections are varicella-zoster virus disease and respiratory tract infections. Assessment of the risk of infection in each period and the identification of patients at higher risk of specific infections are critical to the appropriate management of infectious complications after autologous hematopoietic stem cell transplantation.

Epidemiology of infections in cancer patients

Although major advances in the care of cancer patients over the past several decades have resulted in improved survival, infectious complications remain a significant cause of morbidity and mortality. To successfully identify, treat, and prevent infections, a comprehensive understanding of risk factors that predispose to infection and of commonly encountered pathogens is necessary. In addition, clinicians must keep abreast of the changing epidemiology of infections in this population. As therapeutic modalities continue to evolve, as established pathogens become increasingly drug resistant, and as new pathogens are discovered, successful management of infections will continue to present challenges in the years to come.

Differential proteomic analysis of Aspergillus fumigatus morphotypes reveals putative drug targets

Aspergillus fumigatus is the main etiological agent of invasive aspergillosis, an important opportunistic infection for neutropenic patients. The main risk groups are patients with acute leukemia and bone marrow transplantation recipients. The lack of an early diagnostic test together with the limited spectrum of antifungal drugs remains a setback to the successful treatment of this disease. During invasive infection the inhaled fungal conidia enter the morphogenic cycle leading to angioinvasive hyphae. This work aimed to study differentially expressed proteins of A. fumigatus during morphogenesis. To achieve this goal, a 2D-DIGE approach was applied to study surface proteins extractable by reducing agents of two A. fumigatus morphotypes: germlings and hyphae. Sixty-three differentially expressed proteins were identified by MALDI-ToF/MS. We observed that proteins associated with biosynthetic pathways and proteins with multiple functions (miscellaneous) were over-expressed in the early stages of germination, while in hyphae, the most abundant proteins detected were related to metabolic processes or have unknown functions. Among the most interesting proteins regulated during morphogenesis, two putative drug targets were identified, the translational factor, eEF3 and the CipC-like protein. Neither of these proteins are present in mammalian cells.

Implementation of national comprehensive cancer network evidence-based guidelines to prevent and treat cancer-related infections

Clinical practice guidelines are an important result of evidence-based research. However, current clinical practice remains out of step with the rapid pace of research advancements. Often, decades pass before research is translated into clinical practice. The National Comprehensive Cancer Network (NCCN) has created evidence-based clinical guidelines to promote effective clinical practice. Formerly, the NCCN established guidelines to reduce cancer-related infections only for neutropenic patients; however, they have expanded their guidelines beyond neutropenia to prevent and treat cancer-related infections. Implementing scientific evidence into clinical practice is challenging and complex, and healthcare professionals should understand barriers to implementing clinical practice guidelines to ensure successful translation into practice. This article provides a brief review of NCCN guidelines and describes common barriers encountered during implementation. In addition, a conceptual framework is offered to help identify and address potential concerns before and after adoption of guidelines.

Posaconazole prophylaxis in patients with acute myelogenous leukaemia--results from an observational study

Patients with acute myelogenous leukaemia (AML) and neutropenia after chemotherapy are at high risk for life-threatening invasive fungal disease (IFD), in particular, invasive aspergillosis (IA). The aim of the study was to evaluate data on characteristics, risk factors, complications and additional antifungal treatment of patients with AML receiving posaconazole prophylaxis (PP) after chemotherapy in an actual clinical setting. A retrospective single-centre observational study on 40 patients with AML, median age 66 years, was conducted. PP 200 mg three times daily was given routinely. After 76 cycles of remission induction chemotherapy followed by PP, median duration of 31 days (range 6-61 days), no fatal case occurred. The majority of patients had at least one additional risk factor for IFD and during 32 cycles (42.1%), three risk factors were present. During 40 therapy cycles (52.6%), fever of unknown origin occurred. Pneumonia was diagnosed after 23 cycles (30.3%), thereof one case of proven IA (1.3%). PP was interrupted in 25 cycles (32.9%) and was followed by systemic antifungal therapy with different agents, with a median duration 15 days (range: 6-32 days). PP appears to be an effective and well-tolerated protection against IFD for AML patients under natural clinical conditions.

Formal adult infectious disease specialist consultations in the outpatient setting at a comprehensive cancer center (1998-2008): diverse and impactful

PURPOSE

The literature on the impact of infectious disease (ID) consulations in the outpatient treatment of cancer is scarce.

METHODS

The medical records of consecutive adult patients with cancer formally evaluated by two board-certified ID specialists in an outpatient setting at our institution over a 10-year period (1998-2008) were reviewed retrospectively. The patients' demographics, referring departments, purposes for consultation, ID specialist recommendations, and overall impact of consultations on outcome were analyzed.

RESULTS

We identified 598 patients who underwent ID specialist consultations. Most of them had solid tumors (53%), predominantly breast cancer, whereas non-Hodgkin's lymphoma was the most common hematologic malignancy. Almost half of the patients (45%) had active malignancies, but few of them were severely neutropenic (8%) or had been receiving high doses of corticosteroids (17%). The most frequent requests for consultation were culture or serologic test (15%), and treatment of cellulitis and/or surgical wound infections (14%). Of 337 isolated pathogens, the most prevalent were methicillin-resistant Staphylococcus aureus (13%) and Pseudomonas aeruginosa (8%), as well as atypical mycobacteria (16%) and Aspergillus species (11%). ID specialists provided alternative diagnoses in 53% of the cases, including identification of a different infection (46%), a noninfectious etiology (29%), colonization (16%), and drug-related toxic effects (9%). Overall, we deemed the contribution of the ID specialist to be significant in 62% of the consultations.

CONCLUSIONS

ID specialists contribute significantly to the outpatient care of individuals with cancer.

[Children with cancer and respiratory viral infection: epidemiology, diagnosis and treatment options]

Community-adquired respiratory viral infection is the most common cause of febrile infection in children, and an important cause of infection to consider in children with cancer. Nevertheless, there are few well-designed, controlled studies in this population, which makes it difficult to understand the importance, behaviour and management of these viruses in immunocompromised children. New diagnostic techniques in PCR-based microbiology, could provide many opportunities for early diagnosis, preventing the spread of the virus and to implement the correct therapy. It is important to design appropriate prospective studies to assess these types of infections in children with cancer. In this review we analyse the main studies published in the literature, evaluating the epidemiology, diagnosis and management of children with cancer and respiratory viral infection.

Mapping interactions between germinants and Clostridium difficile spores

Germination of Clostridium difficile spores is the first required step in establishing C. difficile-associated disease (CDAD). Taurocholate (a bile salt) and glycine (an amino acid) have been shown to be important germinants of C. difficile spores. In the present study, we tested a series of glycine and taurocholate analogs for the ability to induce or inhibit C. difficile spore germination. Testing of glycine analogs revealed that both the carboxy and amino groups are important epitopes for recognition and that the glycine binding site can accommodate compounds with more widely separated termini. The C. difficile germination machinery also recognizes other hydrophobic amino acids. In general, linear alkyl side chains are better activators of spore germination than their branched analogs. However, L-phenylalanine and L-arginine are also good germinants and are probably recognized by distinct binding sites. Testing of taurocholate analogs revealed that the 12-hydroxyl group of taurocholate is necessary, but not sufficient, to activate spore germination. In contrast, the 6- and 7-hydroxyl groups are required for inhibition of C. difficile spore germination. Similarly, C. difficile spores are able to detect taurocholate analogs with shorter, but not longer, alkyl amino sulfonic acid side chains. Furthermore, the sulfonic acid group can be partially substituted with other acidic groups. Finally, a taurocholate analog with an m-aminobenzenesulfonic acid side chain is a strong inhibitor of C. difficile spore germination. In conclusion, C. difficile spores recognize both amino acids and taurocholate through multiple interactions that are required to bind the germinants and/or activate the germination machinery.

Aspergillus DNA contamination in blood collection tubes

Fungal polymerase chain reaction (PCR)-based diagnostic methods are at risk for contamination. Sample collection containers were investigated for fungal DNA contamination using real-time PCR assays. Up to 18% of blood collection tubes were contaminated with fungal DNA, probably Aspergillus fumigatus. Lower proportions of contamination in other vessels were observed.

Kinetic evidence for the presence of putative germination receptors in Clostridium difficile spores

Clostridium difficile is a spore-forming bacterium that causes Clostridium difficile-associated disease (CDAD). Intestinal microflora keeps C. difficile in the spore state and prevents colonization. Following antimicrobial treatment, the microflora is disrupted, and C. difficile spores germinate in the intestines. The resulting vegetative cells are believed to fill empty niches left by the depleted microbial community and establish infection. Thus, germination of C. difficile spores is the first required step in CDAD. Interestingly, C. difficile genes encode most known spore-specific protein necessary for germination, except for germination (Ger) receptors. Even though C. difficile Ger receptors have not been identified, taurocholate (a bile salt) and glycine (an amino acid) have been shown to be required for spore germination. Furthermore, chenodeoxycholate, another bile salt, can inhibit taurocholate-induced C. difficile spore germination. In the present study, we examined C. difficile spore germination kinetics to determine whether taurocholate acts as a specific germinant that activates unknown germination receptors or acts nonspecifically by disrupting spores' membranes. Kinetic analysis of C. difficile spore germination suggested the presence of distinct receptors for taurocholate and glycine. Furthermore, taurocholate, glycine, and chenodeoxycholate seem to bind to C. difficile spores through a complex mechanism, where both receptor homo- and heterocomplexes are formed. The kinetic data also point to an ordered sequential progression of binding where taurocholate must be recognized first before detection of glycine can take place. Finally, comparing calculated kinetic parameters with intestinal concentrations of the two germinants suggests a mechanism for the preferential germination of C. difficile spores in antibiotic-treated individuals.

Antibiotic management of febrile neutropenia: current developments and future directions

Mortality due to febrile neutropenia has decreased since the concept of empiric therapy became standard care. However, infectious complications remain the most common adverse events of chemotherapy. bacterial epidemiology has changed during the past decades. There is currently an increasing trend in infections due to Gramnegative bacteria which have higher rates of resistance for a variety of reasons.The use of biomarkers for diagnosis remains a domain of further investigation. Since the patient population with febrile neutropenia is very heterogeneous, models of risk assessment have been developed with the most commonly used today being the mASCC score.Oral antibiotic treatment seems to be appropriate in low-risk patients. In moderate or high-risk patients monotherapy is the most common option. However, due to emerging resistance this could change by next year. Some new antibiotics have been developed, but experience in the treatment of neutropenic fever is limited. The use of antibiotics for prophylaxis remains controversial, although recent studies suggest a reduction in death from all causes.

Classification of invasive fungal disease in patients with acute myeloid leukaemia

Invasive fungal diseases (IFD) are a major cause of morbidity and mortality in patients with acute myeloid leukaemia (AML). Their incidence has risen dramatically in recent years. The diagnosis of IFDs remains difficult, even if the European Organisation for the Research and Treatment of Cancer (EORTC)/Mycosis Study Group (MSG) criteria are applied for study purposes to classify the likelihood of these infections. These criteria have been developed for clinical trials, and their relevance in clinical settings outside a clinical trial remains unknown. We evaluated the impact of the EORTC/MSG criteria and a modification thereof for clinical purposes in patients with AML. We retro-spectively analysed 100 AML patients for the occurrence of IFD. First, EORTC/MSG criteria were applied to classify the patients. Second, a modified version of these criteria already used in clinical trials was used to re-classify the patients. Fifty-seven patients developed an invasive fungal infection. Following the original criteria, 43% were classified as 'possible' IFD, whereas 7% each were classified as 'probable' and 'proven' IFD. After application of the modified criteria, only 9% of the patients remained 'possible' IFD, whereas 41% were 'probable'. The occurrence of 'proven' cases was not altered by the modification and thus remained 7%. The application of modified criteria for the classification of IFD in AML patients leads to a considerable shift from 'possible' IFD (according to conventional EORTC criteria) towards 'probable' IFD. Nevertheless, neither the old EORTC criteria nor their modification was designed for use in clinical practice. As this study underscores the uncertainty in the diagnosis of IFD, the need for a clinically applicable classification is obvious.

Pharmacokinetics of vancomycin in adult cancer patients

Background and Objectives. Gram-positive infections are prevalent among cancer patients and vancomycin therapy is often initiated empirically. A typical vancomycin pharmacokinetics is observed in such patients. The aim of the study was to evaluate the pharmacokinetics of vancomycin in this patient population and compare it to that of normal population.

Method and Results. The pharmacokinetics of vancomycin was examined retrospectively in two groups of patients — 18 cancer patients (age 43.4 ± 22.1 years) and 13 patients without cancer (age 48.5 ± 20.2 years). Following the administration of intermittent intravenous infusion of 15 mg/kg of vancomycin, peak and trough vancomycin serum concentration were determined after the third dose or at steady state as per standard of care. Vancomycin data were analyzed according to a one-compartment open model. Pharmacokinetic parameters such as clearance (CL), volume of distribution (Vd), and K elimination (ke) were calculated. Both Vd and CL were significantly higher in the cancer group (Mean Vd was 70 ± 45 L in the cancer group and 31.1 ± 8.3 L in the noncancer group, p-value 0.002; CL mean was 110.1 ± 42 mL/min in the cancer group and 71.2 ± 22.2 mL/min in the noncancer group, p-value 0.005). There was no significant difference in K elimination and half-life (t1/2).

Conclusion. Cancer patients may require higher than usual dosing regimens to ensure optimal therapeutic concentrations, since vancomycin CL and Vd is significantly higher in these patients, a dosing schedule as high as 60 mg/kg/day may be needed for cancer patients.

Risk factors associated with methicillin-resistant Staphylococcus aureus colonization on hospital admission among oncology patients

A nested case-control study at a tertiary care facility was conducted to assess potential risk factors for colonization with methicillin-resistant Staphylococcus aureus (MRSA) on admission among oncology patients. Risk factors for any S aureus and MRSA colonization on admission in oncology patients are consistent with previous studies in general populations. In addition, recent chemotherapy as a risk factor is a unique finding in this population.