CHAPTER 20. Endocarditis in Oncology Patients by Sara E. Cosgrove and Aruna Subramanian

/in /by

ABSTRACT

Although relatively uncommon in the general population with an incidence of 2-7 cases per 100,000 person years, infective endocarditis (IE) is associated with significant morbidity and mortality. Recent studies suggest that the incidence of IE in oncology patients overall has increased and that it is reasonable to maintain a baseline suspicion in patients who present with the appropriate clinical scenario. An in-depth review of epidemiology, risk factors, clinical presentation, diagnosis, medical and surgical management of IE in oncology patients is presented in this chapter.

CHAPTER 19. Central Nervous System Infections in Cancer Patients by Victor Mulanovich, Amar Safdar

/in /by

ABSTRACT

Central nervous system (CNS) infections represent an important complication in cancer patients undergoing therapy. These infections are often difficult to diagnose, a high level of suspicion, prompt investigation and institution of appropriate and early therapy remains critical for improved outcomes. A wide variety of viruses, bacteria, mycobacteria, fungi and parasitic meningeal and brain disease makes empiric selection of antimicrobial therapy a daunting task. The factors that assist in the selection of initial therapy includes predisposing factors such as a) presence of prosthetic devices, b) surgical manipulation, c) host’s immune defects either related to underlying malignancy, antineoplastic chemotherapy, or d) complications arising from stem cell transplantation to name a few. For instance, patients with severe neutropenia have an increased risk for bacterial meningitis due to Gram negative organisms, and fungal brain abscesses, where as patients with profound cellular immune defects are susceptible to Listeria monocytogenes infection, Cryptococcal meningitis and recrudescent herpes viruses and toxoplasmosis. In evaluation of patients with CNS infections a knowledge of non-infectious causes that are clinically difficult to distinguish from an infection also need to be considered. In this regard, neoplastic meningitis, paraneoplastic syndrome and recently described chemotherapy-induced reversible posterior leukoencephalopathy syndrome, are to name a few. Mental confusion and fever related to a drug is a important consideration in this population

CHAPTER 18. Management of Genitourinary Tract Infections by Amar Safdar, Maurie Markman

/in /by

ABSTRACT

The risk of developing an infection in patients with genitourinary tract malignancy arise from a host of factors such as 1) tumor encroachment and invasion of adjacent structures; 2) tumor necrosis; 3) complications arising from antineoplastic chemotherapy; 4) early and late effects of abdomiopelvic radiation therapy; 5) surgical tumor excision and removal of internal organs; 6) structural abnormalities resulting from surgical diversion procedures; and 7) other causes that disrupt protective barriers in urinary and female reproductive tract. The spectrum of causative organisms most frequently arise from patients’ endogenous microflora. The vagina, lower urinary and intestinal tract colonization with bacteria and yeast serves as important sources for infection. The normal aerobic and anaerobic vaginal bacterial flora may be altered in patients undergoing antineoplastic therapy. Among factors that influence changes in colonization includes, hormonal dysfunction, frequent exposure to broad-spectrum antimicrobial agents, antineoplastic therapy, hospitalization and instrumentation. Peritonitis, intraabdominal abscess, complicated urinary tract infection, surgical wound infection, skin and soft tissue infection such as cellulitis, necrotizing fasciitis, clostridial myonecrosis, and septic pelvic thrombophlebitis are important infectious complications encountered in patients with genitourinary tract malignancies.

CHAPTER 17. Management of Reactivation of Hepatitis B and Hepatitis C during antineoplastic therapy by Marta Davila, Harrys A. Torres

/in /by

ABSTRACT

Hepatitis viruses can cause serious illness in patient with cancer and those who have undergone stem cell transplantation.  Patients with hematological malignancies chronically infected with either Hepatitis B virus or Hepatitis C virus are at risk for viral reactivation following chemotherapy.  Hepatitis B virus reactivation is a common and serious complication but preventable. Hepatitis C virus has a lower reactivation rate following chemotherapy than Hepatitis B virus, but its presentation can be severe and non-preventable. In this chapter, we review the management of reactivation of viral hepatitis during antineoplastic therapy affecting patients with cancer or stem cell transplantation.

CHAPTER 16. Neutropenic Enterocolitis and Clostridium difficile Infections BY Amar Safdar, Bruno P. Granwehr, Stephen A. Harold, Herbert L. DuPont

/in /by

ABSTRACT

Neutropenic enterocolitis is best defined as a clinical syndrome with features indistinguishable from other causes of bowel inflammation. Patients usually present with fever, abdominal pain, diarrhea, and have evidence of thickened bowel wall.  This potentially fatal complication is not uncommon in neutropenic children, whereas, in adults neutropenic enterocolitis is often seen in older patients with advanced cancer undergoing salvage chemotherapy for a hematologic malignancy. Patients with oro-intestinal mucosal damage following antineoplastic therapy are at an increased risk. The diagnosis is based on clinical features and evidence of diffuse or localized bowel wall thickening on CT scan; presence of air with in the bowel wall “pneumatosis intestinalis” indicates serious disease with an increased risk of perforation. Treatment is generally supportive with strict bowel rest, parenteral hydration and nutritional support, along with broad spectrum antimicrobials. Myeloid growth factors promote early recovery form neutropenia. Surgery is reserved for patients with perforation of bowel with complicated peritonitis. In this chapter a comprehensive discussion regarding Clostridium difficile (Cdiff) is presented with emphasis on risk factors, clinical presentation and antimicrobial therapy.

CHAPTER 15. Bacterial Colonization and Host Immunity by Coralia N. Mihu, Karen J. Vigil, Javier Adachi

/in /by

ABSTRACT

The gastrointestinal (GI) tract is a highly evolved anatomical and functional structure that encounters a vast array of antigens, food particles and microorganisms on a daily basis. The intestine has to perform the daunting function of absorbing nutrients essential for human life, while keeping us protected from luminal antigens, particles and pathogens. The adult human intestine is home to an enormous number of microorganisms that is extraordinarily complex, collectively known as intestinal microbiota. Understanding our relationship with commensal flora has gained more depth in recent years; new data demonstrate that gastro-intestinal microbiota plays an important role in defense against pathogenic organisms. Since it is only a thin monolayer of epithelial cells that separates us from the intestinal flora and pathogens, the intestine has acquired specialized cells organized in complex structures that have to perform the function of defending us against pathogens by initiating innate and adaptive immune responses. By constant signaling and communication, intestinal immune cells are organized in a vast and complex network that contributes to maintenance of homeostasis.

CHAPTER 14. Mucosal Barrier Injury and Infections by Nicole M.A. Blijlevens, Peter J. Donnelly

/in , /by

ABSTRACT

Neutropenia is well known as a risk factor for infectious complications of patients treated for hematological malignancies. Less is known about the impact of intensive chemotherapy on the epithelial innate immunity that protects us from infections due to opportunistic pathogens that reside on the mucosal surfaces. Injury to the mucosal barrier leads to barrier dysfunction, perturbed microbial signaling and inadequate host responses all of which increase the risk for life-threatening clinically- and microbiologically-defined infections. Greater awareness of mucosal barrier injury should help the physician to know better when and how to act when fever occurs during neutropenia innate immune system (e.g. complement, lysozyme, lectins), especially epithelial cells of the digestive tract and skin for protection against potentially lethal infectious complications. These epithelia form an anatomical and immunological barrier often referred to as the integument that serves as the front line against microbial invasion. Although these epithelia are highly organized and sophisticated structures, the barrier they create is not invincible to microorganisms, certainly not after it is damaged by anti-cancer therapy. Adequate supportive care is predicated by recognition of the disintegration of the primary host defense mechanisms aimed at early recognition and treatment of infection to improve survival.

CHAPTER 13. Non-Infectious Lung Infiltrates that may be Confused with Pneumonia in the Cancer Patient by Rana Kaplan, Lara Bashoura, Vickie R. Shannon, Burton F. Dickey, Diane E. Stover

/in , /by

ABSTRACT

Pneumonia is the leading cause of death from infection among cancer patients and second most common cause of death after uncontrolled cancer itself.  Therefore, the prevention, diagnosis and treatment of pneumonia are critical to outcomes among cancer patients.  During the workup of a symptom or sign, such as cough, fever or chills, abnormalities in imaging studies of the lungs are commonly detected.  Consideration of the differential diagnosis of a lung infiltrate in a cancer patient includes both infectious, as well as several common non-infectious, causes.  Failure to accurately diagnose non-infectious causes of lung infiltrates can lead to unnecessary treatment with antibiotics, and, more importantly, in failure to address the underlying pathophysiologic process.  This chapter is focused on the many clinical presentations that mimic infectious pneumonia.

CHAPTER 12. Pneumonia in the Cancer Patients by Scott E. Evans, Amar Safdar

/in , /by

ABSTRACT

Lower respiratory tract infections result in unacceptably high mortality among cancer patients.  Pneumonias cause death in this population both directly through impairment of gas exchange and progression to system infection/sepsis, as well as indirectly by precluding delivery of necessary, but immuncompromising, anti-neoplastic therapies.1-3  Malignancy and treatment-related impairments of host immune responses and the emergence of multidrug-resistant (MDR) organisms associated with recurrent exposures to hospital environments may not only enhance the risks of mortality, but also exacerbate the difficulty of diagnosing pneumonia in the cancer setting.  As a consequence of disordered inflammatory responses, the typical clinical observations of pneumonia, including purulent respiratory secretions and early radiographic findings may be in apparent or absent.  A comprehensive review of etiology, clinical presentation, diagnosis and management of pulmonary infections is presented in this chapter.

CHAPTER 11. Intravascular Device-Related Infections Catheter Salvage Strategies and Prevention of Device-Related Infection by Nasia Safdar, Dennis G. Maki

/in , /by

ABSTRACT

The use of intravascular devices for administration of chemotherapeutic drugs, fluids, blood products and nutritional support is essential to the care of patients with cancer. Unfortunately, intravascular devices have great potential to produce iatrogenic disease, especially bloodstream infection originating from colonization of the device used for access or from contamination of the infusate administered through the device. Over two-thirds of all healthcare-associated bacteremias originate from devices for vascular access. Probably more than any other healthcare-associated infection, IVDR BSI  is eminently preventable. The first step to preserve vascular access is a highly effective institutional program for prevention of IVDR BSI. In recent years, high-quality research studies have delineated key measures for prevention, such as chlorhexidine for cutaneous antisepsis, maximal barrier precautions, antiinfective-impregnated catheters, and the use of a CVC insertion “bundle” , and IVDR BSI rates in the ICU have declined markedly in most  hospitals. However, despite adherence to best practices, IVDR BSI continues to pose formidable challenges, especially in patients with cancer. Catheter salvage in the context of established IVDR BSI is particularly challenging but recent advances such as antibiotic lock technique are now providing previously unavailable options.