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Biomedical subjects

M B Edmond

Publications and source records attributed to M B Edmond.

At least 19 recordsLinked to original sources

National surveillance of nosocomial blood stream infection due to species of Candida other than Candida albicans: frequency of occurrence and antifungal susceptibility in the SCOPE Program. SCOPE Participant Group. Surveillance and Control of Pathogens of Epidemiologic.

A national surveillance program of nosocomial blood stream infections (BSI) in the USA between April 1995 and June 1996 revealed that Candida was the fourth leading cause of nosocomial BSI, accounting for 8% of all infections. Forty-eight percent of 379 episodes of candidemia were due to species other than Candida albicans. The rank order of non-C. albicans species was C. glabrata (20%) > C. tropicalis (11%) > C. parapsilosis (8%) > C. krusei (5%) > other Candida spp. (4%). The species distribution varied according to geographic region, with non-C. albicans species predominating in the Northeast (54%) and Southeast (53%) regions, and C. albicans predominating in the Northwest (60%) and Southwest (70%) regions. In vitro susceptibility studies demonstrated that 95% of non-C. albicans isolates were susceptible to 5-fluorocytosine, and 84% and 75% were susceptible to fluconazole and itraconazole, respectively. Geographic variation in susceptibility to itraconazole, but not other agents, was observed. Isolates from the Northwest and Southeast regions were more frequently resistant to itraconazole (29-30%) than those from the Northeast and Southwest regions (17-18%). Molecular epidemiologic studies revealed possible nosocomial transmission (five medical centers). Continued surveillance for the presence of non-C. albicans species among hospitalized patients is recommended.

Antifungal Agents

National surveillance of nosocomial blood stream infection due to Candida albicans: frequency of occurrence and antifungal susceptibility in the SCOPE Program.

Surveillance of nosocomial blood stream infections (BSI) in the USA between April 1995 and June 1996 revealed that Candida was the fourth leading cause of nosocomial BSI, accounting for 8% of all infections. Fifty-two percent of 379 episodes of candidemia were due to Candida albicans. In vitro susceptibility studies using the 1997 National Committee for Clinical Laboratory Standards reference method demonstrated that 92% of C. albicans isolates were susceptible to 5-fluorocytosine and 90% were susceptible to fluconazole and itraconazole. Geographic variation in susceptibility of fluconazole and itraconazole was observed. Isolates from the Northwest and Southeast regions were more frequently resistant to fluconazole (13.3-15.5%) and to itraconazole (17.2-20.0%) than those from the Northeast and Southwest regions (2.9-5.5% resistant to fluconazole and itraconazole). Continued surveillance for infections caused by C. albicans and other species of Candida among hospitalized patients is recommended.

Antifungal Agents

Vancomycin-resistant Staphylococcus aureus: infection control considerations.

The lessons of the antibiotic era are crystal clear: in the footrace between humans and microbes, the organisms' genetic repertoire and efficient response to environmental changes will win the day. New antibiotics are essential, but their shelf life will be enhanced only if used wisely and sparingly. The antibiotic era is continually threatened by inappropriate decisions regarding use, inappropriate choices, and unnecessary durations of treatment. In concert with improved prescribing habits, efforts to identify and isolate resistant organisms introduced from outside institutions are essential. Last, continual energy is needed to influence the behavior of health care professionals and to maintain optimal infection control policies and procedures. We remain optimistic about the ability of infectious diseases physicians to respond appropriately to continued microbial challenges with research, education, and wise practice.

Anti-Bacterial Agents

The epidemiology of hemorrhage related to cardiothoracic operations.

OBJECTIVE: To define the epidemiology, risk factors, and unadjusted cost of hemorrhages related to cardiothoracic operations. STUDY DESIGN: We conducted two case-control studies to evaluate the risk of hemorrhage following cardiothoracic operations. The definition of hemorrhage required one of the following: reoperation for bleeding, postoperative loss of greater than 800 mL of blood over 4 hours, or surgeon-diagnosed excessive intraoperative bleeding. SETTING: The cardiothoracic surgery service of a university hospital. RESULTS: Of 511 patients undergoing cardiothoracic operations, 93 (18%) met the definition of hemorrhage. In the first case-control study, 3 (14%) of 21 cases and 0 of 42 controls died (odds ratio [OR], 15.0; 95% confidence interval [CI95], 1.18-191.55). Compared with controls, cases received significantly more packed red blood cells intraoperatively (OR, 1.18/100 mL; CI95, 1.01-1.38), and significantly more platelets (OR, 3.26/100 mL; CI95, 1.47-7.26) and fresh frozen plasma (OR, 1.73/100 mL; CI95, 1.05-.84) in the intensive-care unit. Cases were more likely than controls to receive protamine postoperatively (OR, 3.74; CI95, 1.27-11.02). Previous sternotomy, preoperative aspirin or heparin, and preoperative laboratory values did not predict bleeding. The median unadjusted hospital cost was $3,458 higher for patients who suffered hemorrhage than for controls. To decrease costs, hetastarch (acquisition cost $45/500 mL) was substituted for albumin (acquisition cost $76/100 mL) in the pump priming solution (estimated possible cost savings, $7,000-$53,000/year). Because hemorrhage rates increased subsequently, we conducted a second case-control study that identified patient age (P=.02) and use of greater than 5 mL/kg of hetastarch (OR, 1.82) as risk factors for hemorrhage. The cost of treating hemorrhages exceeded all estimates of possible cost savings ($7,000-$53,000 per year). CONCLUSIONS: Our definition of hemorrhage identified patients who required increased volumes of blood products and who had an increased crude mortality rate and a higher unadjusted cost of hospitalization. Patient age and hetastarch use were risk factors for hemorrhage. Efforts to save money by substituting less expensive products inadvertently may increase costs by increasing the probability of perioperative adverse events.

Aged

Hospital specificity, region specificity, and fluconazole resistance of Candida albicans bloodstream isolates.

In a survey of bloodstream infection (BSI) isolates across the continental United States, 162 Candida albicans isolates were fingerprinted with the species-specific probe Ca3 and the patterns were analyzed for relatedness with a computer-assisted system. The results demonstrate that particular BSI strains are more highly concentrated in particular geographic locales and that established BSI strains are endemic in some, but not all, hospitals in the study and undergo microevolution in hospital settings. The results, however, indicate no close genetic relationship among fluconazole-resistant BSI isolates in the collection, either from the same geographic locale or the same hospital. This study represents the first of three fingerprinting studies designed to analyze the origin, genetic relatedness, and drug resistance of Candida isolates responsible for BSI.

Antifungal Agents

Inducible amp C beta-lactamase producing gram-negative bacilli from blood stream infections: frequency, antimicrobial susceptibility, and molecular epidemiology in a national surveillance program (SCOPE).

A surveillance study of nosocomial blood stream infections [Surveillance and Control of Pathogens of Epidemiologic Importance (SCOPE)] was conducted during a 14-month period in 1995 to 1996 in approximately 50 American medical centers. Among the 4725 blood stream infections, the etiologic agent was Enterobacter spp. in 230, Citrobacter freundii in 24, and Serratia marcescens in 65. The vast majority of these isolates (89%) had been sent to the University of Iowa including 198 Enterobacter spp. (46 Enterobacter aerogenes, 141 Enterobacter cloacae, 11 other Enterobacter spp.), 23 C. freundii, and 62 S. marcescens. Because these species are capable of producing Amp C beta-lactamase, we examined their susceptibility to 12 broad-spectrum antimicrobial agents. The frequency of resistance to ceftazidime and the molecular epidemiology of ceftazidime-resistant strains was also examined. Among the Enterobacter spp. and C. freundii isolates, resistance to third generation cephalosporins (ceftazidime, ceftriaxone) and broad-spectrum semisynthetic penicillins (piperacillin), with or without an enzyme inhibitor (piperacillin/tazobactam), was high, e.g., 35 to 50%. The S. marcescens isolates were quite susceptible to all agents tested. Both imipenem and cefepime were active against virtually all isolates tested including 84 stably derepressed Amp C-producing ceftazidime-resistant strains of Enterobacter spp. and C. freundii. The overall rank order of activity for the six best agents against these Amp C-producing strains was: imipenem (100% susceptible) > amikacin = cefepime (98.6%) > ciprofloxacin = gentamicin = ofloxacin (93.6 to 94.0%). Molecular typing studies of ceftazidime-resistant E. cloacae using an automated ribotyping system, as well as pulsed-field gel electrophoresis, indicated that although clonal spread of a single strain occurred in some of the medical centers, most of the episodes of bacteremia were caused by patient-unique strains. Control of these resistant organisms will require attention to microbiologic recognition of phenotypes, to infection control practices, and to limiting the overuse of certain extended spectrum beta-lactams.

Anti-Bacterial Agents

Nosocomial enterococcal blood stream infections in the SCOPE Program: antimicrobial resistance, species occurrence, molecular testing results, and laboratory testing accuracy. SCOPE Hospital Study Group.

Characteristics of nosocomial enterococcal blood stream infection (NEBSI) isolates obtained from patients at 41 U.S. hospitals participating in the SCOPE Program were studied. Isolates from 480 episodes of NEBSI were characterized according to species and antimicrobial susceptibility profile. Selected isolates were also identified to species and vancomycin resistance genotype using polymerase chain reaction based methods. Polymerase chain reaction genotyping and ribotyping were used as genetic markers for molecular epidemiologic typing. Enterococci were the third most common cause of nosocomial blood stream infection in this study, accounting for 11.7% of all isolates reported. Enterococcus faecalis was the most common species (59.6%), followed by E. faecium (19.4%). Species identification errors involving E. faecium, E. durans, E. avium, and E. raffinosus were observed. Vancomycin resistance was observed in 36.4% of all participating medical centers and varied from 11.1% of medical centers in the Northwest to 60.9% of medical centers in the Southwest. Vancomycin-resistant enterococci accounted for 20.6% of NEBSI in the Northeast, 11.4% in the Southeast, 11.1% in the Southwest, and 9.5% in the Northwest regions. VanA genotypes predominated in the Northeast and Southwest, whereas vanA and vanB genotypes were equally prevalent in the Northwest and Southeast. Molecular typing studies identified strains that were unique to individual hospitals as well as strains that were prevalent in several different hospitals. NEBSI with vancomycin-resistant enterococci continues to escalate among hospitalized patients in all geographic areas of the USA.

Anti-Bacterial Agents

Nosocomial streptococcal blood stream infections in the SCOPE Program: species occurrence and antimicrobial resistance. The SCOPE Hospital Study Group.

Nosocomial blood stream infections due to streptococci represent an increasingly important problem, particularly among neutropenic cancer patients. This problem is compounded by the emerging resistance to antimicrobial agents commonly used for empiric or prophylactic treatment of hospitalized patients. In this study, we examined the species distribution and antimicrobial susceptibility profile of 295 streptococcal nosocomial blood stream isolates from more than 30 U.S. medical centers (SCOPE National Surveillance Program). Streptococci accounted for 5.9% of all nosocomial blood stream isolates reported. The viridans group streptococci (VGS) were the most frequently isolated streptococci (50.8%), followed by the beta-haemolytic streptococci (31.9%) and pneumococci (13.2%). The beta-haemolytic streptococci were dominated by serogroup B strains (63%), followed by serogroups A and G. Of these organisms, 193 strains were referred for subsequent monitor susceptibility testing. Approximately 14% of S. pneumoniae, 9.2% of VGS, and 0% of beta-haemolytic streptococci were resistant to penicillin. Ceftriaxone was highly active against virtually all isolates (93-100% susceptible) except the VGS (77% susceptible). The rank order for activity of the four agents tested against the 193 isolates was vancomycin > ceftriaxone > penicillin > erythromycin. Importantly, 69% of the penicillin intermediate and resistant strains of VGS were also resistant to at least one additional antimicrobial (31% resistant to ceftriaxone, 51% resistant to erythromycin, 15% resistant to both ceftriaxone and erythromycin). The relatively poor activity of erythromycin against virtually all streptococci and the frequent association of macrolide resistance with penicillin resistance among the VGS suggests that both macrolides and beta-lactam agents might have limited value as prophylactic agents for dental procedures and in empiric or prophylactic use in neutropenic patients.

Anti-Bacterial Agents

Hospital epidemiology--1997.

Selected issues for hospital epidemiology are presented. The issues of infection control, employee health and quality assessment cross the traditional department and reporting lines and require a multidisciplinary approach utilizing the epidemiological method. Programs seeking enhanced value--high quality outcomes per dollar cost--will likely support such an approach.

Epidemiology

Vancomycin-resistant Staphylococcus aureus: perspectives on measures needed for control.

Given the dramatic increase in the incidence of vancomycin resistance among the enterococci and experimental evidence for the transfer of vancomycin resistance from enterococci to Staphylococcus aureus, there is concern that strains of S. aureus will emerge that are resistant to vancomycin. The result would be a highly virulent pathogen for which effective antimicrobial therapy would not be available. To prevent the nosocomial transmission of such an organism, stringent infection control policies need to be developed and implemented. We offer proposals that are based on the limited data available on the transmission and control of S. aureus and that may be used as starting points for the development of formal guidelines for the isolation of colonized and infected patients and for microbiology laboratory precautions.

Clinical Protocols

Vancomycin-resistant enterococcal bacteremia: natural history and attributable mortality.

Previous studies have shown that bacteremia due to vancomycin-resistant Enterococcus species (VRE) is associated with mortality of 17%-100%, but comorbid conditions may have confounded the estimates. We designed a historical cohort study to determine the mortality attributable to VRE bacteremia. Twenty-seven patients with VRE bacteremia were identified as cases. Within 7 days of the onset of bacteremia, severe sepsis developed in 12 patients (44%) and septic shock developed in 10 (37%). Case patients were closely matched to control patients without VRE bacteremia (1:1) by time of hospitalization, duration of exposure, underlying disease, age, gender, and surgical procedure. The mortality was 67% among cases and 30% among matched controls (P = 0.1). Thus, the mortality attributable to VRE bacteremia was 37% (95% confidence interval [CI], 10%-64%) and the risk ratio for death was 2.3 [CI, 1.2-4.1). We conclude that VRE bacteremia is associated with high rates of severe sepsis and septic shock. The attributable mortality approaches 40%, and patients who have VRE bacteremia are twice as likely to die than closely matched controls.

Adult

Vancomycin-resistant Enterococcus faecium bacteremia: risk factors for infection.

We describe an outbreak of vancomycin-resistant Enterococcus faecium (vanA phenotype) bacteremia on the oncology ward of a tertiary care community hospital. In 10 of the 11 cases the patients had leukemia and were neutropenic (median duration of neutropenia, 21 days) at the time of bacteremia. On average, patients received six antibiotic agents for a total of 61 agent-days prior to development of vancomycin-resistant E. faecium bacteremia. The mortality rate was 73%. Molecular typing of 22 isolates revealed that the majority (83%) represented a common strain, indicating nosocomial spread. When the 11 cases were compared to 22 matched control patients, gastrointestinal colonization with vancomycin-resistant E. faecium (odds ratio [denominator, 0] infinity, P = .005) and the use of antimicrobial agents with significant activity against anaerobes (metronidazole, clindamycin, and imipenem; odds ratio infinity, P = .02) were found to be risk factors for the development of vancomycin-resistant E. faecium bacteremia. Since no proven therapy for such infection exists, there is an urgent need to identify effective measures to prevent and control the development of vancomycin-resistant E. faecium bacteremia.

Adult

Molecular epidemiology of an outbreak of meningococcal disease in a university community.

Over a 2-month period, five cases of serogroup C meningococcal disease occurred in Iowa City, Iowa. Two patients were unacquainted university students who had independently visited another university with endemic meningococcal disease. Isolates from these patients had DNA fingerprints identical to those of the isolates responsible for infections on the other campus. Three cases for which the patients' isolates had a different DNA fingerprint were linked to visiting a local tavern. To disrupt the outbreak, the University of Iowa offered free meningococcal vaccine to all students. This report demonstrates that outbreaks of meningococcal disease may be due to more than one circulating strain and illustrates the utility of pulsed-field gel electrophoresis in defining the molecular epidemiology of meningococcal infections.

Adolescent

Malaria: protection of the international traveler.

Thorough counseling with emphasis on the importance of mosquito bite avoidance, as well as on compliance with prophylactic antimalarial regimens, remains an important task for the physician preparing a patient for international travel. Chloroquine continues to be the drug of choice for prophylaxis in areas not reporting chloroquine resistance. Otherwise, mefloquine is the first-line agent. Under special circumstances, alternatives to mefloquine can be employed and include doxycycline or proguanil plus chloroquine.

Antimalarials