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Summary and conclusionThe association among malignancies, the immunocompromised host and infectious morbidity and mortality are well established. Infections are the most common cause of early morbidity and mortality. In approximately ,70 % of patients with cancer in general and those with haematological malignancies in particular.The patients with haematological malignancies and those undergoing autologus bone marrow transplantation are immunocompromised either as a part of disease process or as consequence of chemotherapy. Broadly defined, an immunocompromised host has an alteration in phagocytic, cellular or humoral immunity that increases the risk of an infectious complication or an apportunistic processAs a rule a variety of host defense defect will ocurr in patients with haematological malignancies undergoing chemotherapy that will predispose them to infection.1- Integumentary and mucosal barrier2- Neutropenia3- Deficient immunoglobulin production4- Defects in cellular immunity5- Splenectomy6- Malnutrition7- Implanted vascular catheters8- Exogenous and endogenous microbial flora9- Interface of colonization and infectionNeutropenia remain the major defect for many patients and therefore continues to severe as a model system for dealing with infection in patients who are immunocompromised. Neutropenia defined when absolute neutrophil count dropped below 500-1000 µL. the longer the duration of neutropenia and the more the rapid the decline in white cells, the greater the incidence of infection. In addition to neutropenia severe alteration in either humoral or cellular immunity can lead to life threatening infectionAlso these patients have an alteration or breaches of their skin or mucosal defense barriers that permits microorganisms to cause either local or systemic infectionMucosal barrier injury (MBI) provides a portal of entery to the systemic circulation for commensal oral and gastrointestinal microorganisms. Thus, the ability to treat or prevent severe (MBI) is an important step toward decreasing the infectious complications experienced by patients given intensive chemotherapyThe spectrum of organisms responsible for infectious complications in patients with haematological malignancies is daunting, since virtually any organism can become invasive if host defences are severely impaired . Infectiuos complications may be caused by different pathogens including : bacteria, viruses, fungi, and / or parasitesAlthough no guideline is sacrosanct, the most probable offending organisms can be identified on the basis of the degree and duration of immunosuppression and the type of immune defect ( isolated or part of multifactorial process ). The predominant organisms are also influenced by the patient’s treatment regimen as well as by where the patient resides and receives careHowever the primary infection is almost caused by a bacterium, while the organisms that cause superinfection when the empiric antibiotic therapy for presumed infection has already been used, include antibiotic resistant bacteria, fungi and viruses . There is increasing trend of gram negative organisms developing resistance to commonly used antibiotics. Gram positive bacteria including Enterococcus spp. and coagulase negative staphylococci are also showing emerging resistance to vancomycin .Fungal infection is a major complication in patients with malignant haematologic disorders who are receiving intensive myelosuppressive chemotherapy or undergoing bone marrow transplantation .Steps of diagnosis of infection in patients with haematological malignancies1- Specimen2- Microscopy and Staining3- Culture systems and Bacterial identification4- Antigen detection5-Serology6- Molecular TechniquesReal-time PCR has revolutionized the way clinical microbiology laboratories diagnose many human microbial infections. This testing method combines PCR chemistry with fluorescent probe detection of amplified product in the same reaction vessel. In general, both PCR and amplified product detection are completed in an hour or less, which is considerably faster than conventional PCR detection methods. Real-time PCR assays provide sensitivity and specificity equivalent to that of conventional PCR combined with Southern blot analysis, and since amplification and detection steps are performed in the same closed vessel, the risk of releasing amplified nucleic acids into the environment is negligible. The combination of excellent sensitivity and specificity, low contamination risk, and speed has made real-time PCR technology an appealing alternative to culture- or immunoassay-based testing methods for diagnosing many infectious diseases.Because immunodeficient patient are predictably at risk of infection by opportunistic pathogens, the administration of antibiotics with activity against select organisms is frequently used as a preventive measure .The potential benefits of such chemoprophylaxis measures are clear. Unfortunately, such strategies pose some hazards, including medication toxicities and the selection of resistant organisms including fungi .The prevention of infection is an important outcome to measure in patients with cancer because infectious complications are a significant cause of morbidity and mortality. Nurses play a vital role in the prevention of infection in patients with cancer through nursing practice, research, and patient education. However, many common nursing interventions to prevent infection are based on tradition or expert opinion and have not been subjected to scientific examination .A significant impact in preventing infections can be made with simple educational and hygienic measures because most organisms that cause infections in immunocompromised patients are present as flora in the surrounding environment. Careful hand washing remains the single most effective procedures for preventing infection. It is essential that patients, families, and health care staff be instructed and frequently reminded of proper technique and required repetition. Printed material combined with verbal instructions to reinforce strategies may be useful.Febrile neutropenia is an expected complication during treatment of aggressive haematological malignancies and hematopoietic cell transplantation. A prospective cohort trial to determine the effects and safety of prophylactic fluoroquinolone administration, and rotation of empiric antibiotics for neutropenic fever in this patient population A prophylactic and cycling antibiotic schedule was successfully implemented on a haematological malignancy and hematopoietic cell transplant unit. gram-negative bacteremia was significantly decreased, without emergence of resistance. Concerns with Gram-positive resistance will require further observation .More attention has been directed toward colony-stimulating factors involved in maturation and proliferation of hematopoietic stem cells. Granulocyte colony-stimulating factor (G-CSF) induces the formation and function of granulocyte, and granulocyte-macrophage colony-stimulating factor (GM-CSF) induces both granulocyte and monocyte proliferation and activation. Since the initial cloning and clinical trials in the late 1980s and eventual licensure, use has expanded to include stimulation of hematopoiesis and therapy for neutropenia in a variety of settings .With continued progress in treating haematological malignancies using more effective and more myelosuppressive and immunosuppressive agents, the role of supportive care has become more prominent. In addition, analyses identifying prognostic factors for specific infections may identify a high risk population and allow prophylactic strategies to be more cost effective by avoiding treatment of patients who are unlikely to suffer such complications.Recommendations• Careful hand washing remains the single most effective procedures for preventing infection.• The care of patient mucocutaneous surfaces should receive special attention ,especially during periods of predictable neutropenia .• When the risk for particular infections is determined to be significant, preemptive therapy or chemoprophylaxis is one strategy used to minimize infections .• More attention has been directed toward colony-stimulating factors involved in maturation and proliferation of hematopoietic stem cells.• Analyses identifying prognostic factors for specific infections may identify a high risk population and allow prophylactic strategies to be more cost effective by avoiding treatment of patients who are unlikely to suffer such complications.
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