Search PubMed⌕ Search

Biomedical subjects

Issam I Raad

Publications and source records attributed to Issam I Raad.

At least 55 records · Page 3Linked to original sources

Catheter-related bloodstream infection caused by Mycobacterium brumae.

Mycobacterium brumae is a rapidly growing environmental mycobacterial species identified in 1993; so far, no infections by this organism have been reported. Here we present a catheter-related M. brumae bloodstream infection in a 54-year-old woman with breast cancer. The patient presented with high fever (39.7 degrees C), and >1,000 colonies of M. brumae grew from a quantitative culture of blood drawn through the catheter. A paired peripheral blood culture was negative, however, suggesting circulational control of the infection. The patient was treated empirically with meropenem and vancomycin, and the fever resolved within 24 h. The catheter was removed a week later, and from the tip M. brumae was isolated a second time, suggesting catheter colonization. The organism was identified by colonial morphology, sequence analysis of the 16S rRNA gene, and biochemical tests.

Bacteremia↗

West Nile encephalitis in 2 hematopoietic stem cell transplant recipients: case series and literature review.

Most human cases of West Nile virus infection are acquired via bites from an infected mosquito. In some cases, infection may also be transmitted by infected blood products or transplanted organs. There have been recent publications suggesting that chemotherapy and immunosuppression may increase a person's risks of developing central nervous system disease if the person is infected with the West Nile virus. Because patients undergoing hematopoietic stem cell transplantation not only are immunocompromised, but also receive multiple blood products, they are at a particularly high risk for acquiring symptomatic disease if exposed to the West Nile Virus. We describe here 2 patients who underwent hematopoietic transplantation at our institution and subsequently developed fatal West Nile virus infections.

Aged↗

Treatment of febrile neutropenic patients with cancer who require hospitalization: a prospective randomized study comparing imipenem and cefepime.

BACKGROUND: The objective of the current study was to compare the efficacy and safety of imipenem and cefepime in the treatment of adult patients with cancer who had fever and neutropenia requiring hospitalization according to Infectious Disease Society of America criteria. METHODS: In the current prospective randomized clinical trial at a university-affiliated tertiary cancer center, adult patients with cancer who had fever (> or = 38.3 degrees C or > or = 38.0 degrees C for > 2 hours) and neutropenia (< or = 500/mm(3) or < 1000/mm(3) but declining) requiring hospitalization were randomized to receive either cefepime or imipenem. Vancomycin or amikacin was added on suspicion of gram-positive or gram-negative bacterial infection, respectively. RESULTS: Patients who received an imipenem regimen or a cefepime regimen were comparable in terms of age, gender, underlying malignancy, prior transplantation, degree and trend of neutropenia, and presence of central venous catheters (P > or = 0.3). An intent-to-treat analysis showed a 68% response rate to the imipenem regimen, compared with a 75% response rate to the cefepime regimen (P = 0.2). The rates of antibiotic-related adverse events and superinfections also were comparable (P = 0.6). There was no difference in response among patients who received imipenem or cefepime alone compared with patients who also received vancomycin or amikacin (P = 1.0). Leukemia was the only independent risk factor associated with a poor outcome (odds ratio, 4.6; 95% confidence interval, 1.9-10.7; P < 0.0001). CONCLUSIONS: Imipenem and cefepime had similar efficacy and safety profiles in the treatment of adult cancer patients with fever and neutropenia who required hospitalization. The addition of either vancomycin or amikacin may not be necessary.

Adolescent↗

Efficacy and toxicity of caspofungin in combination with liposomal amphotericin B as primary or salvage treatment of invasive aspergillosis in patients with hematologic malignancies.

BACKGROUND: Caspofungin (CAS) as salvage therapy for refractory invasive aspergillosis (IA) had a response rate of 45% among a heterogeneous group of patients. The use of CAS with other agents is appealing given its unique mechanism of action. Therefore, the authors retrospectively evaluated the efficacy and toxicity of CAS plus liposomal amphotericin B (LipoAMB) in patients with documented (definite or probable) or possible IA. METHODS: Patients were evaluable for outcome if they received CAS/LipoAMB for at least 7 days. Patients who received CAS and LipoAMB sequentially were excluded. All patients were evaluable for toxicity. Outcome was assessed weekly and at the end of therapy. Stable disease and progression were considered treatment failures. RESULTS: Forty-eight patients with documented (n=23) or possible (n=25) IA were identified between March 2001 and December 2001. The majority of the patients (65%) received CAS/LipoAMB as salvage therapy for progressive IA despite 7 or more days of previous LipoAMB monotherapy. The overall response rate was 42%. No significant toxic effects were seen. Factors associated with failure at the end of therapy were documented IA (P=0.03), significant steroid use before the study (P=0.02), and duration of combination therapy for less than 14 days (P=0.01). The response rate in patients with progressive documented IA was low (18%). CONCLUSIONS: The CAS/LipoAMB combination is a promising preemptive therapy for IA and was generally well tolerated. This combination might have limited benefit as salvage therapy for documented IA.

Adolescent↗

Infections in patients with aplastic anemia: experience at a tertiary care cancer center.

BACKGROUND: Infection is a significant cause of death in patients with aplastic anemia (AA). However, few recent studies have examined infectious complications in patients with AA. METHODS: The authors retrospectively evaluated the type of infections, associated pathogens, and outcome of infectious episodes (IEs) in patients with AA who were treated at The University of Texas M. D. Anderson Cancer Center between July 1994 and June 2000. RESULTS: Fifty-two patients with a median age of 37 years (range, 3-83 years) were identified. Overall, 104 IEs were documented in 42 patients (81%). The most common microbiologically documented infections were bacteremias (38%) followed by pneumonias (16%). Most patients (55%) had bacterial infections, mainly caused by gram-positive cocci. Multidrug-resistant, gram-negative bacilli also were not uncommon in this patient population. Five of 12 patients who died during the study period died of infection. All of these patients had invasive fungal infections, mostly due to molds. All five patients had prolonged and severe neutropenia. CONCLUSIONS: Infections remain a major cause of death in patients with AA. Bacterial infections, especially those caused by gram-positive cocci, constitute the main cause of IE. Invasive mold infections, however, are the major cause of death in this patient population.

Adolescent↗

Evaluation of the silver iontophoretic catheter in an animal model.

Silver iontophoretic catheters (SIC) were shown to be highly efficacious in preventing catheter infections in vitro and in a rabbit model (J. Infect. Dis. 173 (1996) 495). Furthermore, we sought to determine the safety and durability of SIC prior to use in humans. A total of 30 New Zealand white rabbits (3-4 kg) were randomly assigned to one of three groups whereby SIC or Arrow Guard (AG) catheters were tunneled and inserted in the jugular vein. All animals were followed for 2-12 weeks after catheter implantation. Blood was collected from each rabbit for assessment of toxicity and determination of silver levels. The electrical current generated by each SIC was measured once daily. At the end of the follow-up period, tissue samples were collected from the skin surrounding the catheter, the lungs, spleen, and liver. Microscopically, none of the tissues examined from any of the animals showed evidence of silver deposits, silver toxicity, thermal or electrical injury. The silver levels in the animals that received the SIC ranged from 0.1 to 2.23 microg/l with a mean of 0.62 (+/-0.44 SD). In conclusion SIC were safe with normal serum silver levels and were not associated with any local or systemic toxicity.

Animals↗

Aspergillosis caused by non-fumigatus Aspergillus species: risk factors and in vitro susceptibility compared with Aspergillus fumigatus.

Invasive aspergillosis (IA) caused by inherently more antifungal-resistant non-fumigatus Aspergillus species has become an important life-threatening complication in severely immunocompromised patients with cancer. The purpose of this study was to compare the relative incidence of, risk factors for, and in vitro correlation of amphotericin B and itraconazole with the clinical outcome of IA caused by Aspergillus fumigatus with those of IA caused by non-fumigatus Aspergillus spp. in patients with cancer. A retrospective search of our tertiary care cancer center's microbiology laboratory reports from 1998-2001 revealed 40 patients with cancer and IA. A non-fumigatus Aspergillus species caused IA in 28 (70%) of those patients. A. fumigatus was the predominant cause of late-onset IA after bone marrow transplantation (p = 0.05), whereas IA due to non-fumigatus Aspergillus spp. was more common in patients with neutropenia (p = 0.01). The minimum inhibitory concentration (50/90) and minimum fungicidal concentration (50/90) for amphotericin B were higher in the non-fumigatus Aspergillus spp. group than in the A. fumigatus one. The Aspergillus species distribution in IA cases in our institution shows a predominance of the more antifungal-resistant or -tolerant non-fumigatus Aspergillus spp.

Adult↗

Sequential exposure of Aspergillus fumigatus to itraconazole and caspofungin: evidence of enhanced in vitro activity.

We investigated the in vitro activity of sequential itraconazole and caspofungin against 10 isolates of Aspergillus fumigatus. Previous exposure of A. fumigatus to itraconazole resulted in dose-dependent enhanced effects of caspofungin and vice versa. Our finding suggests a preferential role for azole-caspofungin sequential combinations and merits further in vivo investigation.

Antifungal Agents↗

Candidemia in a tertiary care cancer center: in vitro susceptibility and its association with outcome of initial antifungal therapy.

Since the 1990s, changing trends have been documented in species distribution and susceptibility to bloodstream infections caused by Candida species in cancer patients. However, few data are available regarding the association between in vitro antifungal susceptibility and outcome of candidemia in this patient population. We therefore evaluated the association of in vitro antifungal susceptibility and other risk factors with failure of initial antifungal therapy in cancer patients with candidemia. Candidemia cases in cancer patients from 1998 to 2001 (n = 144) were analyzed retrospectively along with their in vitro susceptibility to amphotericin B, fluconazole, and itraconazole (National Committee for Clinical and Laboratory Standards M27-A method). Patients were evaluable for outcome analysis if they received continuous unchanged therapy with either fluconazole or amphotericin B for >/=5 days. We excluded cases of mixed candidemia. In vitro susceptibility testing data of the first Candida bloodstream isolate were analyzed. Appropriate therapy was defined as that using an active in vitro antifungal for >/=5 days. For fluconazole susceptible-dose dependent Candida species, we defined appropriate therapy as a fluconazole dose of >/=600 mg/day. The Candida species distribution was 30% Candida albicans, 24% Candida glabrata, 23% Candida parapsilosis, 10% Candida krusei, 9% Candida tropicalis, and 3% other. Overall, amphotericin B was the most active agent in vitro, with only 3% of the isolates exhibiting resistance to it (>1 mg/L). Dose-dependent susceptibility to fluconazole and itraconazole was seen in 13% and 21% of the isolates, respectively, while resistance to fluconazole and itraconazole was seen in 13% and 26%, respectively.Eighty patients were evaluable for outcome analysis. In multivariate analysis, the following factors emerged as independent predictors of failure of initial antifungal therapy: leukemia (p = 0.01), bone marrow transplantation (p = 0.006), and intensive care unit stay at onset of infection (p = 0.02). Inappropriate antifungal therapy, as defined by daily dose and in vitro susceptibility, was not shown consistently to be a significant factor (it was significant in multivariate analysis, p = 0.04, but not in univariate analysis), indicating the complexity of the variables that influence the response to antifungal treatment in cancer patients with candidemia.

Adolescent↗

Antibiotic-impregnated catheters associated with significant decrease in nosocomial and multidrug-resistant bacteremias in critically ill patients.

OBJECTIVE: To evaluate the impact of using central venous catheters (CVCs) impregnated with the combination of minocycline and rifampin on nosocomial bloodstream infections (BSIs), morbidity, and mortality in cancer patients in the ICU. DESIGN: Prospective surveillance study consisting of the following two time periods: September 1997 through August 1998 (ie, fiscal year [FY] 1998); and from September 1998 through August 1999 (ie, FY 1999). SETTING: ICUs of a tertiary care hospital in Houston, TX. PATIENTS: Cancer patients in the medical ICU (MICU) and surgical ICU (SICU). INTERVENTIONS: ICUs started using CVCs impregnated with the minocycline-rifampin combination at the beginning of FY 1999. MEASUREMENTS AND MAIN RESULTS: The rates of nosocomial BSIs and other patients' characteristics were compared for the two study periods to determine the impact of using the impregnated catheters in the ICU. Patients' characteristics, including antibiotic use, were comparable for the two study periods in both the MICU and the SICU. The rate of nosocomial BSIs in the MICU unit decreased from 8.3 to 3.5 per 1,000 patient-days (p < 0.01), and decreased in the SICU from 4.8 to 1.3 per 1,000 patient-days (p < 0.01) in FY 1999. Nosocomial vancomycin-resistant enterococcus (VRE) bacteremia also decreased significantly (p = 0.004). Length of stay in the MICU and SICU significantly decreased in FY 1999 (p < 0.01 and p = 0.03, respectively). The duration of hospitalization decreased for MICU and SICU patients (p = 0.06 and p < 0.01, respectively). The rate of catheter-related infections decreased from 3.1 to 0.7 per 1,000 patient-days in FY 1999 (p = 0.02). The decrease in infections resulted in net savings of at least $1,450,000 for FY 1999. CONCLUSIONS: The use of antibiotic-impregnated CVCs in the MICU and SICU was associated with a significant decrease in nosocomial BSIs, including VRE bacteremia, catheter-related infections, and lengths of hospital and ICU stays.

Adolescent↗

Guidelines for the prevention of intravascular catheter-related infections. Centers for Disease Control and Prevention.

These guidelines have been developed for practitioners who insert catheters and for persons responsible for surveillance and control of infections in hospital, outpatient, and home health-care settings. This report was prepared by a working group comprising members from professional organizations representing the disciplines of critical care medicine, infectious diseases, health-care infection control, surgery anesthesiology interventional radiology pulmonary medicine, pediatric medicine, and nursing. The working group was led by the Society of Critical Care Medicine (SCCM), in collaboration with the Infectious Disease Society of America (IDSA), Society for Healthcare Epidemiology ofAmerica (SHEA), Surgical Infection Society (SIS), American College of Chest Physicians (ACCP), American Thoracic Society (ATS), American Society of Critical Care Anesthesiologists (ASCCA), Association for Professionals in Infection Control and Epidemiology (APIC), Infusion Nurses Society (INS), Oncology Nursing Society (ONS), Society of Cardiovascular and Interventional Radiology (SCVIR), American Academy of Pediatrics (AAP), and the Healthcare Infection Control Practices Advisory Committee (HICPAC) of the Centers for Disease Control and Prevention (CDC) and is intended to replace the Guideline for Prevention of Intravascular Device-Related Infections published in 1996 These guidelines are intended to provide evidence-based recommendations for preventing catheter-related infections. Major areas of emphasis include 1) educating and training health-care providers who insert and maintain catheters; 2) using maximal sterile barrier precautions during central venous catheter insertion; 3) using a 2% chlorhexidine preparation for skin antisepsis; 4) avoiding routine replacement of central venous catheters as a strategy to prevent infection; and 5) using antiseptic/antibiotic impregnated short-term central venous catheters if the rate of infection is high despite adherence to other strategies (i.e., education and training, maximal sterile barrier precautions, and 2% chlorhexidine for skin antisepsis). These guidelines also identify performance indicators that can be used locally by health-care institutions or organizations to monitor their success in implementing these evidence-based recommendations.

Adult↗

Intravascular catheter-related infections: new horizons and recent advances.

BACKGROUND: Central venous catheters have become essential devices for the management of critically and chronically ill patients; however, their use is often complicated by catheter-related bloodstream infections (CRBSIs), many of which could be prevented. METHODS: This report is based on a literature review of more than 100 published articles in intravascular catheter-related infections. This review focuses on the most recent advances in the methods of diagnosis of CRBSI as they relate to its pathogenesis and on novel preventive techniques and approaches to management. RESULTS: Catheter-related bloodstream infections may be diagnosed by different methods, including simultaneous quantitative blood cultures, with the central blood culture yielding at least 5-fold colony-forming units greater than the peripheral blood culture, and simultaneous blood cultures, whereby the catheter-drawn blood culture becomes positive at least 2 hours before the peripheral blood culture. Novel preventive techniques include the use of ionic silver, an anticoagulant/antimicrobial flush solution, a new aseptic hub, and antimicrobial impregnation of catheters and dressings. Management of CRBSIs should be based on whether the infection is complicated or uncomplicated. CONCLUSIONS: Novel technologies that have been proved to aid in the diagnosis and prevention of CRBSIs should be considered in clinical practice. The management approach should be based on the type of microorganism causing the infection and on whether the infection is complicated or uncomplicated.

Bacteremia↗

The epidemiology of Candida glabrata and Candida albicans fungemia in immunocompromised patients with cancer.

PURPOSE: Candida glabrata is an increasing cause of candidemia, especially at cancer and bone marrow transplant centers where fluconazole is used for antifungal prophylaxis. This yeast is less susceptible to fluconazole in vitro than is Candida albicans. We compared the characteristics of patients who had C. glabrata and C. albicans candidemia at a large cancer center. SUBJECTS AND METHODS: We searched the microbiological laboratory reports and identified 116 cases of C. glabrata candidemia between 1993 and 1999. The 116 cases of C. albicans candidemia that occurred most closely in time (before or after each case of C. glabrata candidemia) served as the control group. Data were collected from patients' medical records. RESULTS: When compared with patients who had C. albicans infection, patients with C. glabrata candidemia more often had an underlying hematologic malignancy (68 [59%] vs. 26 [22%], P = 0.0001), had an Acute Physiology and Chronic Health Evaluation (APACHE) II score > or =16 (55 [48%] vs. 28 [25%], P = 0.0002), and received fluconazole prophylaxis (57 [49%] vs. 8 [7%], P = 0.0001). Patients with C. albicans candidemia more often had concomitant infections (101 [87%] vs. 78 [67%], P = 0.0003) and septic thrombophlebitis (11 [10%] vs. 2 [2%], P = 0.01). Among patients treated with antifungal therapy, those with C. albicans candidemia had a significantly greater overall response to therapy (83/104 [80%] vs. 60/97 [62%], P = 0.005) and to primary therapy (74/104 [71%] vs. 45/97 [46%], P = 0.0003). Amphotericin B preparations were not more effective than fluconazole (19/45 [42%] vs. 20/38 [53%], P = 0.5) in patients with C. glabrata candidemia. Fluconazole was less effective against C. glabrata than against C. albicans (20/38 [53%] vs. 57/74 [77%], P = 0.008). CONCLUSION: C. glabrata has emerged as an important cause of candidemia, especially among neutropenic patients who receive fluconazole prophylaxis.

APACHE↗

Efficacy of antimicrobial-impregnated silicone sections from penile implants in preventing device colonization in an animal model.

OBJECTIVES: To assess, in an animal study, the efficacy of minocycline/rifampin-impregnated silicone sections of pump bulbs from penile implants in preventing device colonization by Staphylococcus aureus. Infection constitutes a very serious complication of penile implants. METHODS: Minocycline/rifampin-impregnated and control silicone pump bulb sections from penile implants were each inoculated with about 10(3) to 10(4) colony-forming units of S. aureus. After 8 hours of incubation with bacteria at room temperature, the test devices were allowed to dry for 30 minutes, and then subcutaneously implanted in the backs of rabbits. Eleven rabbits each received a total of six devices. The wounds were sutured, and the rabbits were monitored daily, then killed at 2 days after surgery. In vitro zones of inhibition against S. aureus by the minocycline/rifampin-impregnated and control devices were also determined. RESULTS: All of the six tested antimicrobial-impregnated devices but none of the control devices produced zones of inhibition in vitro against S. aureus (mean zone of inhibition by antimicrobial-impregnated devices of 23 mm). The antimicrobial-impregnated devices retrieved from rabbits were sixfold less likely than were the control devices to be colonized with S. aureus (2 [6%] of 33 versus 11 [33%] of 33, respectively; P = 0.011). CONCLUSIONS: The results of this animal study indicate that minocycline/rifampin-impregnated pump bulb sections from penile implants provide antimicrobial activity in vitro against S. aureus and protect against staphylococcal colonization of devices implanted for 2 days in animals.

Animals↗

Guidelines for the prevention of intravascular catheter-related infections.

BACKGROUND: Although many catheter-related bloodstream infections (CR-BSIs) are preventable, measures to reduce these infections are not uniformly implemented. OBJECTIVE: To update an existing evidenced-based guideline that promotes strategies to prevent CR-BSIs. DATA SOURCES: The MEDLINE database, conference proceedings, and bibliographies of review articles and book chapters were searched for relevant articles.Studies Included: Laboratory-based studies, controlled clinical trials, prospective interventional trials, and epidemiological investigations. OUTCOME MEASURES: Reduction in CR-BSI, catheter colonization, or catheter-related infection. SYNTHESIS: The recommended preventive strategies with the strongest supportive evidence are education and training of healthcare providers who insert and maintain catheters; maximal sterile barrier precautions during central venous catheter insertion; use of a 2% chlorhexidine preparation for skin antisepsis; no routine replacement of central venous catheters for prevention of infection; and use of antiseptic/antibiotic impregnated short-term central venous catheters if the rate of infection is high despite adherence to other strategies (i.e. education and training, maximal sterile barrier precautions and 2% chlorhexidine for skin antisepsis). CONCLUSION: Successful implementation of these evidence-based interventions can reduce the risk for serious catheter-related infection.

Adolescent↗