Emergence of vancomycin resistance in Staphylococcus aureus. Glycopeptide-Intermediate Staphylococcus aureus Working Group.
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BACKGROUND: Since the emergence of methicillin-resistant Staphylococcus aureus, the glycopeptide vancomycin has been the only uniformly effective treatment for staphylococcal infections. In 1997, two infections due to S. aureus with reduced susceptibility to vancomycin were identified in the United States. METHODS: We investigated the two patients with infections due to S. aureus with intermediate resistance to glycopeptides, as defined by a minimal inhibitory concentration of vancomycin of 8 to 16 microg per milliliter. To assess the carriage and transmission of these strains of S. aureus, we cultured samples from the patients and their contacts and evaluated the isolates. RESULTS: The first patient was a 59-year-old man in Michigan with diabetes mellitus and chronic renal failure. Peritonitis due to S. aureus with intermediate resistance to glycopeptides developed after 18 weeks of vancomycin treatment for recurrent methicillin-resistant S. aureus peritonitis associated with dialysis. The removal of the peritoneal catheter plus treatment with rifampin and trimethoprim-sulfamethoxazole eradicated the infection. The second patient was a 66-year-old man with diabetes in New Jersey. A bloodstream infection due to S. aureus with intermediate resistance to glycopeptides developed after 18 weeks of vancomycin treatment for recurrent methicillin-resistant S. aureus bacteremia. This infection was eradicated with vancomycin, gentamicin, and rifampin. Both patients died. The glycopeptide-intermediate S. aureus isolates differed by two bands on pulsed-field gel electrophoresis. On electron microscopy, the isolates from the infected patients had thicker extracellular matrixes than control methicillin-resistant S. aureus isolates. No carriage was documented among 177 contacts of the two patients. CONCLUSIONS: The emergence of S. aureus with intermediate resistance to glycopeptides emphasizes the importance of the prudent use of antibiotics, the laboratory capacity to identify resistant strains, and the use of infection-control precautions to prevent transmission. (+info)
Legionnaires' disease on a cruise ship linked to the water supply system: clinical and public health implications.
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The occurrence of legionnaires' disease has been described previously in passengers of cruise ships, but determination of the source has been rare. A 67-year-old, male cigarette smoker with heart disease contracted legionnaires' disease during a cruise in September 1995 and died 9 days after disembarking. Legionella pneumophila serogroup 1 was isolated from the patient's sputum and the ship's water supply. Samples from the air-conditioning system were negative. L. pneumophila serogroup 1 isolates from the water supply matched the patient's isolate, by both monoclonal antibody subtyping and genomic fingerprinting. None of 116 crew members had significant antibody titers to L. pneumophila serogroup 1. One clinically suspected case of legionnaires' disease and one confirmed case were subsequently diagnosed among passengers cruising on the same ship in November 1995 and October 1996, respectively. This is the first documented evidence of the involvement of a water supply system in the transmission of legionella infection on ships. These cases were identified because of the presence of a unique international system of surveillance and collaboration between public health authorities. (+info)
Weekly administration of 2-chlorodeoxyadenosine in patients with hairy-cell leukemia is effective and reduces infectious complications.
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BACKGROUND AND OBJECTIVE: It has been widely demonstrated that one single 7-day course continuous infusion (c.i.) 2-chlorodeoxyadenosine (2-CdA) at a dose of 0.1 mg/kg daily is dramatically effective in inducing high and prolonged complete remission (CR) rates in patients with hairy-cell leukemia (HCL). However, 2-CdA administration often results in severe neutropenia and lymphocytopenia both responsible for the infectious complications observed in these patients. We previously reported preliminary data regarding the effectiveness and toxicity of a modified protocol of 2-CdA administration (0.15 mg/kg 2 hours infusion once a week for 6 courses) in 25 HCL patients. This treatment schedule produced a similar overall response rate compared to standard 2-CdA regimen and appeared to be followed by a lower incidence of infectious episodes. In the present study we report response rate and toxicity of weekly 2CdA administration in a larger cohort of patients and with a longer follow-up. DESIGN AND METHODS: In a group of HCL patients with a pronounced decrease in neutrophils count (< 1 x 10(9)/L), we modified the standard protocol (0.1 mg/kg daily x 7 days c.i.) by administering 2-CdA at a dose of 0.15 mg/kg 2 hours infusion once a week for 6 courses. Thirty HCL patients, 24 males and 6 females with a median age of 56 years (range 37-76), entered into this protocol. Seventeen out of 30 patients were at diagnosis while the remaining 13 had been previously treated with alpha-interferon (alpha-IFN) (7), or 2-CdA (4) or deoxycoformycin (DCF) (2). RESULTS: Overall, 22/30 (73%) patients achieved CR and 8 (27%) partial remission (PR) with a median duration of response at the time of writing of 35 months, ranging from 6 to 58 months. Five patients (1 CR and 4 PR) have so far progressed. The treatment was very well tolerated. Five out of 30 patients (16%) developed severe neutropenia (neutrophils < 0.5 x 10(9)/L) and only in two of them we did register an infectious complication which required treatment with systemic antibiotics and granulocyte colony-stimulating factor (G-CSF). INTERPRETATION AND CONCLUSIONS: In conclusion, we confirm that weekly administration of 2-CdA at a dose of 0.15 mg/kg for 6 courses appears to be very effective in HCL inducing a high CR rate, similar to that observed with daily c.i. administration. CR durability and relapse/progression rates are also comparable to standard 2-CdA schedule. Moreover this new regimen seems to be safer in pancytopenic patients, markedly reducing life-threatening infectious complications. (+info)
Treatment of multiple myeloma.
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BACKGROUND AND OBJECTIVE: Multiple myeloma (MM) accounts for about 10% of all hematologic malignancies. The standard treatment with intermittent courses of melphalan and prednisone (MP) was introduced more than 30 years ago and, since then there has been little improvement in event-free and overall survival (EFS & OS). The aim of this article is to review: 1) the role of initial chemotherapy (ChT), maintenance treatment with alpha-interferon and salvage ChT, 2) the results of high-dose therapy (HDT) followed by allogeneic or autologous stem cell transplantation (allo-SCT and auto-SCT), and 3) the most important supportive measures. EVIDENCE AND INFORMATION SOURCES: The authors of this review have been actively working and contributing with original investigations on the treatment of MM during the last 15 years. In addition, the most relevant articles and recent abstracts published in journals covered by the Science Citation Index and Medline are also reviewed. STATE OF THE ART AND PERSPECTIVES: The importance of avoiding ChT in asymptomatic patients (smoldering MM) is emphasized. The criteria and patterns of response are reviewed. MP is still the standard initial ChT with a response rate of 50-60% and an OS of 2-3 years. Combination ChT usually increases the response rate but does not significantly influence survival when compared with MP. Exposure to melphalan should be avoided in patients in whom HDT followed by auto-SCT is planned, in order to not preclude the stem cell collection. The median response duration to initial ChT is 18 months. Interferon maintenance usually prolongs response duration but in most studies does not significantly influence survival (a large meta-analysis by the Myeloma Trialists' Collaborative Group in Oxford is being finished). In alkylating-resistant patients, the best rescue regimens are VBAD or VAD. In patients already resistant to VBAD or VAD and in those in whom these treatments are not feasible we recommend a conservative approach with alternate day prednisone and pulse cyclophosphamide. While HDT followed by autotransplantation is not recommended for patients with resistant relapse, patients with primary refractory disease seem to benefit from early myeloablative therapy. Although results from large randomized trials are still pending in order to establish whether early HDT intensification followed by auto-SCT is superior to continuing standard ChT in responding patients, the favorable experience with autotransplantation of the French Myeloma Intergroup supports this approach. However, although the complete response rate is higher with intensive therapy, the median duration of response is relatively short (median, 16 to 36 months), with no survival plateau. There are several ongoing trials comparing conventional ChT with HDT/autoSCT in order to identify the patients who are likely to benefit from one or another approach. With allo-SCT there is a transplant-related mortality ranging from 30 to 50% and also a high relapse rate in patients achieving CR. However, 10 to 20% of patients undergoing allo-SCT are long-term survivors (> 5 years) with no evidence of disease and, consequently, probably cured. The use of allogeneic peripheral blood stem cells (PBSC) in order to speed the engraftment and also the use of partially T-cell depleted PBSC which can decrease the incidence of graft-versus-host disease are promising approaches. In the setting of allo-SCT, donor lymphocyte infusion is an encouraging strategy in order to treat or prevent relapses. Finally, important supportive measures such as the treatment of anemia with erythropoietin, the management of renal failure and the use of bisphosphonates are reviewed. (+info)
Feasibility and safety of a new technique of extracorporeal photochemotherapy: experience of 240 procedures.
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BACKGROUND AND OBJECTIVE: Extracorporeal photochemotherapy (ECP) is a therapeutic approach based on the biological effects of ultraviolet light (UV) - A and psoralens on mononuclear cells collected by apheresis. Recently, ECP has been under investigation as an alternative treatment for various immune and autoimmune diseases. The aim of this study was to evaluate the safety and feasibility of a new three-step ECP technique, in terms of reproducibility, acceptance, tolerability, and short and long term side effects. DESIGN AND METHODS: Seventeen patients affected by acute or chronic graft-versus-host disease (GvHD), pemphigus vulgaris, or interferon-resistant chronic hepatitis C and one patient being treated for prevention of heart transplant rejection underwent 240 ECP procedures. MNC collection and processing parameters were recorded, biological effects of UV-A/8 methoxy-psoralen (8-MOP) were evaluated, and short and long term side effects were monitored. RESULTS: At a mean follow up of 7 months (range 2-19) 240 ECP had been completed, a mean of 7,136 mL (range 1,998-10,591) of whole blood having beenprocessed per procedure. The mean of total nucleated cells collected per procedure was 6.5x109 (range 0.65-23.8), with a mean MNC percentage of 85% (41. 4-98%) in a mean final volume of 115.5 mL (37-160). No severe side effects were documented and no infectious episodes occurred throughout the course of the treatment. INTERPRETATION AND CONCLUSIONS: The new ECP technique was highly reproducible as regards the collection and each processing step. Short and long term side effects were mild. No increase in infectious episodes was recorded. All patients willingly underwent ECP, demonstrating an excellent tolerability for the procedure even after several courses. (+info)
Frequency of vaccine-related and therapeutic injections--Romania, 1998.
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In Romania and other countries, therapeutic injections have been associated with transmission of hepatitis B and C viruses, human immunodeficiency virus type 1 (HIV-1), and other bloodborne pathogens. During 1997-1998, acute hepatitis B was associated with recent injections in Romanian children aged <5 years. Injection-associated bloodborne pathogen transmission occurs when infection-control practices are inadequate, and overuse of injections to administer medications might increase opportunities for transmission. To estimate the frequency of therapeutic injections and to describe the attitudes and practices of adults about injections to administer medications, local health departments in Romania surveyed the general population of four districts (Hunedoara, Iasi, Mures, and Prahova [1997 combined population: 2.8 million]) in June 1998. This report summarizes results from these surveys, which indicate that injections are used frequently to administer medications in Romania. (+info)
Application of data mining to intensive care unit microbiologic data.
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We describe refinements to and new experimental applications of the Data Mining Surveillance System (DMSS), which uses a large electronic health-care database for monitoring emerging infections and antimicrobial resistance. For example, information from DMSS can indicate potentially important shifts in infection and antimicrobial resistance patterns in the intensive care units of a single health-care facility. (+info)
Preparing for the next round: convalescent care after acute infection.
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Infections pose a nutritional stress on the growing child. No therapeutic goal is as important as the rapid recovery of preillness weight after acute infections. Successful convalescence, with supernormal growth rates, can be achieved with relatively brief periods of intensive refeeding, offsetting any tendency toward reduced immune defenses or other nutritionally determined susceptibilities to further infection. Since the mother is the only person who can effectively manage convalescent care, she must be given specific tasks with measurable targets in order to reliably oversee the child's rehabilitation. Not generally considered in the realm of preventive medicine, effective home-based convalencent care is the first crucial step in preventing the next round of illness. An approach to the widespread mobilization of mothers to monitor and sustain their children's growth is proposed in this paper. Rather than a passive recipient of health services, the mother becomes the basic health worker, providing diagnostic and therapeutic primary care for her child. Only the mother can break the malnutrition-infection cycle. (+info)