Biomedical subjects
Publications and source records attributed to Larry M Baddour.
Infective endocarditis due to vancomycin-resistant (VR) Enterococcus faecalis has only rarely been reported. We report a case of VR E. faecalis endocarditis that failed to respond to linezolid therapy, outline the virulence traits of the isolate, and review previously published cases of VR E. faecalis endocarditis.
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The VisualDx system (http://www.logicalimages.com/prodVDx.htm) is a JAVA-based decision-support program developed by Logical Images to be used in clinical care to develop differential diagnoses based upon morphologic finding- and patient finding-driven searching. It consists of several modules, many of which are very relevant to infectious diseases specialists, such as Fever & Rash; International Travel; Drug Eruptions; Smallpox Vaccination; Terrorism Recognition; Immunocompromised, HIV or AIDS; Female Genital Rashes & Growths; and Male Genital Rashes & Growths. Unlike books and atlases indexed by disease, with VisualDx, clinicians can enter patient descriptors and lesion morphologies, resulting in rapid assistance with differential diagnosis. VisualDx also increases clinician awareness of, knowledge about, and skills in the recognition of chemical warfare, bioterrorism, and radiation injuries.
Evidence from cohort studies and a randomized clinical trial indicates that annual vaccination against seasonal influenza prevents cardiovascular morbidity and all-cause mortality in patients with cardiovascular conditions. The American Heart Association and American College of Cardiology recommend influenza immunization with inactivated vaccine (administered intramuscularly) as part of comprehensive secondary prevention in persons with coronary and other atherosclerotic vascular disease (Class I, Level B). Immunization with live, attenuated vaccine (administered intranasally) is not currently recommended [corrected] for persons with cardiovascular conditions. It is important to note that influenza vaccination coverage levels overall and in this population remain well below national goals and are marked by disparities across different age and ethnic groups. One of the barriers to vaccination for patients with cardiovascular disease is that cardiology practices frequently do not stock and administer influenza vaccine. Healthcare providers who treat individuals with cardiovascular disease can help improve influenza vaccination coverage rates by providing and strongly recommending vaccination to their patients before and throughout the influenza season.
Evidence from cohort studies and a randomized clinical trial indicates that annual vaccination against seasonal influenza prevents cardiovascular morbidity and all-cause mortality in patients with cardiovascular conditions. The American Heart Association and American College of Cardiology recommend influenza immunization with inactivated vaccine (administered intramuscularly) as part of comprehensive secondary prevention in persons with coronary and other atherosclerotic vascular disease (Class I, Level B). Immunization with live, attenuated vaccine (administered intranasally) is not currently recommended [corrected] for persons with cardiovascular conditions. It is important to note that influenza vaccination coverage levels overall and in this population remain well below national goals and are marked by disparities across different age and ethnic groups. One of the barriers to vaccination for patients with cardiovascular disease is that cardiology practices frequently do not stock and administer influenza vaccine. Healthcare providers who treat individuals with cardiovascular disease can help improve influenza vaccination coverage rates by providing and strongly recommending vaccination to their patients before and throughout the influenza season.
BACKGROUND: Despite the frequent occurrence of bacteremia due to gram-negative organisms in patients with underlying permanent pacemakers (PPMs) or implantable cardioverter defibrillators (ICDs), the outcome and treatment of these patients has received scant attention. In patients with PPMs or ICDs who have Staphylococcus aureus bacteremia, 45% have PPM/ICD infection. METHODS: We conducted a retrospective cohort study over a 7-year period to assess the clinical features and frequency of PPM/ICD infection in patients with gram-negative bacteremia, as well as the incidence of relapse in patients for whom the device was not removed. RESULTS: Forty-nine patients were included in the study; 3 (6%) had either definite (2 patients) or possible (1 patient) PPM/ICD infection. Both patients with definite PPM/ICD infection had clear infection of the generator pocket. None of the other patients with alternate sources of bacteremia developed PPM/ICD infection. Thirty-four patients with retained PPM/ICD were observed for >12 weeks (median time, 759 days), and 2 (6%) developed relapsing bacteremia, although they each had alternative sources of relapse. CONCLUSIONS: In sharp contrast to S. aureus infection, PPM/ICD infection in patients with gram-negative bacteremia was rare, and no patients appeared to have secondary PPM/ICD infection due to hematogenous seeding of the system. Despite infrequent system removal in these patients, relapsing bacteremia among patients who survived initial bacteremia was rarely seen. If secondary PPM/ICD infection occurs in patients with gram-negative bacteremia, it is either uncommon or it is cured with antimicrobial therapy despite device retention.
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RATIONALE: Although the serial dilution technique for quantitative culture of bronchoalveolar fluid is considered to be the gold standard for the diagnosis of ventilator-associated pneumonia, it is more labor intensive than the calibrated loop technique. OBJECTIVE: We sought to determine the agreement between the calibrated loop and serial dilution techniques in the diagnosis of ventilator-associated pneumonia. METHODS: We prospectively measured bacterial colony counts by the serial dilution and calibrated loop techniques in 121 bronchoalveolar lavage samples of 104 patients with suspected ventilator-associated pneumonia. MEASUREMENTS AND MAIN RESULTS: At the time of bronchoscopy, patients had received mechanical ventilation for a median of 8 d. Patients were receiving antibiotics when 90 of the 121 (74.4%) bronchoalveolar samples were obtained. The colony counts of 13 bacterial isolates were too numerous to count by the calibrated loop technique; by serial dilution technique, their counts ranged from 4.70 to 6.74 log10 cfu/ml. Fifty other bacteria had paired colony counts measured by each of the two techniques: the bias (95% confidence interval) between the two techniques was -0.380 (-0.665 to -0.095) log10 cfu/ml, with precision of 1.002 log10 cfu/ml and 95% limits of agreement of -2.344 to 1.584 log10 cfu/ml. Using the threshold of 4 log10 cfu/ml as a criterion for the diagnosis of ventilator-associated pneumonia, there was discordance only for one bacterial organism between the two techniques. CONCLUSIONS: The calibrated loop technique can be used for the diagnosis of ventilator-associated pneumonia using bronchoalveolar lavage fluid.
BACKGROUND: The clinical impact of penicillin resistance on the outcome of pneumococcal pneumonia has remained controversial. We performed a meta-analysis of prospective cohort studies to examine the association between penicillin resistance and short-term all-cause mortality for pneumococcal pneumonia. METHODS: We retrieved studies published in any language by a comprehensive search of the Medline, Current Contents, and Embase databases for all appropriate articles published up to January 2005. We also manually reviewed bibliographies of retrieved articles, recent national treatment guidelines, and review articles. We included prospective cohort studies that involved adult subjects, and we examined the association between penicillin resistance and short-term mortality for pneumococcal pneumonia. Two reviewers independently extracted data on crude and adjusted risk estimates of all-cause mortality for pneumococcal infections with different levels of penicillin resistance and assessed the methodological quality of selected studies. We also contacted authors to obtain additional information. We performed meta-analyses using a random-effect model. RESULTS: Of 1152 articles identified in the search, 10 studies that involved 3430 patients (most of whom were hospitalized) were included. The mortality rate was 19.4% in the penicillin-nonsusceptible Streptococcus pneumoniae group and 15.7% in the penicillin-susceptible S. pneumoniae group. The combined relative risks of all-cause mortality for the penicillin-nonsusceptible, -intermediate, and -resistant S. pneumoniae groups, compared with the penicillin-susceptible S. pneumoniae group, were 1.31 (95% confidence interval [CI], 1.08-1.59), 1.34 (95% CI, 1.13-1.60), and 1.29 (95% CI, 1.01-1.66), respectively. The combined adjusted relative risks of mortality for penicillin-nonsusceptible versus penicillin-susceptible S. pneumoniae group was 1.29 (95% CI, 1.04-1.59) for the 6 studies that adjusted for age, comorbidities, and severity of illness. There was minimal between-study heterogeneity in these analyses. CONCLUSION: Penicillin resistance is associated with a higher mortality rate than is penicillin susceptibility in hospitalized patients with pneumococcal pneumonia. Additional efforts are needed to understand the mechanisms of this association.
PURPOSE: The study's purpose was to identify prognostic factors associated with mortality in Staphylococcus aureus prosthetic valve endocarditis and to determine whether these factors influenced decisions to treat medically versus surgically. We also analyzed whether there was a subset of patients who were cured with medical therapy alone. SUBJECTS AND METHODS: A retrospective review of patients with S aureus prosthetic valve endocarditis was performed. Demographic and clinical data were collected from existing medical records. Severity of illness was classified using American Society of Anesthesiologists (ASA) score. Impact of treatment on in-hospital mortality was assessed using multiple logistic regression analysis. RESULTS: Fifty-five patients met the Duke criteria for definite S aureus prosthetic valve endocarditis. Twenty-three patients were treated medically, and 32 patients had surgical intervention. Overall mortality was 36% (28% in the surgical group and 48% in the medical group). ASA score IV (P < .001) and older age (P = .014) were significant risk factors of mortality. Patients with ASA score IV (P = .037) and multiple prosthetic valves (P = .013) were less likely to undergo surgery. Medically treated patients were older compared with those in the surgical group (median age 66 vs 55 years, P = .04). All 4 patients aged less than 50 years in the medically treated group survived. CONCLUSION: Mortality was generally higher in the medically treated patients with S aureus prosthetic valve endocarditis. Multivariable analysis showed that ASA class IV and bioprosthetic valves were independent predictors of mortality. A subset of medically treated patients characterized by age less than 50 years, ASA score III, and without cardiac, central nervous system, or systemic complications were cured without surgical intervention.
PURPOSE OF REVIEW: Use of electrophysiologic devices (permanent cardiac pacemaker and implantable cardioverter/defibrillator) has been increasing. Infection of these cardiac devices is a devastating complication, and medical treatment alone without device removal is often unsuccessful and frequently leads to infection relapse. This article reviews recent publications that address the diagnosis and management of infected electrophysiologic devices. RECENT FINDINGS: Recent studies have shed new light on the incidence, risk factors, management, and outcome of cardiac device infection. Rates of both cardiac device implantation and infection have been increasing, although the rate of increase of cardiac device infection has outdistanced that of implantation and this has had enormous economic and clinical consequences. SUMMARY: The large majority of cardiac device infections are likely due to pocket site contamination at the time of device placement. Hematogenous seeding from a distant focus of infection, particularly due to Staphylococcus aureus, can account for late-onset infection. Although no prospective studies have been conducted to date, management with parenteral antibiotics and complete device removal is the current standard of care. Further study is needed to better define optimal diagnostic and management interventions, particularly in patients with bloodstream infection and no local chest wall or echocardiographic evidence of cardiac device infection.
OBJECTIVE: To determine the incidence, risk factors, associated pathogens, and outcome of ventilator-associated pneumonia (VAP) in patients admitted to a coronary care unit (CCU). PATIENTS AND METHODS: This retrospective cohort study was performed in the CCU of a single tertiary medical center. Patients who were admitted to the CCU between March 23, 2002, and May 25, 2003, and who required invasive mechanical ventilation for more than 48 hours were included. RESULTS: Of the 92 patients who met the study criteria, 17 (18.5%; 95% confidence interval, 11.9%-27.6%) developed VAP. The incidence of VAP was 36.3 (95% confidence interval, 21.1-58.1) per 1000 days of mechanical ventilation. There were no statistically significant differences in demographics, presence of chronic obstructive pulmonary disease, or use of continuous intravenous sedatives or neuromuscular blockers between patients with and without VAP. The most commonly isolated organisms were methicillin-sensitive Staphylococcus aureus, Sphingomonas paucimobilis, and Stenotrophomonas maltophilia. The median length of stay in the CCU for patients with VAP was 10 days compared to 6 days for patients without VAP (P < .01). Eight (47%) of the 17 patients with VAP died compared to 29 (39%) of 75 patients without VAP (P = .52). CONCLUSIONS: The incidence of VAP in the CCU is similar to or higher than that reported in other intensive care units. The development of VAP in CCU patients is associated with a prolonged CCU stay but not with an increased hospital mortality.
OBJECTIVES: Several factors have been anecdotally reported to increase the risk of prosthetic vascular graft infection (PVGI), a serious complication with high mortality and limb amputation rates. The goal of this study is to confirm purported risk factors using a well-designed statistical model. METHODS: Patients undergoing vascular graft placement at Mayo Clinic Rochester between January 1, 1982 and December 31, 2002 were retrospectively evaluated, excluding redo cases. PVGI cases had to meet one of the following criteria: perigraft air or fluid >8 weeks postoperatively, positive Gram stain or cultures of graft or perigraft material, intraoperative gross purulence, failure of graft incorporation, or exposed graft. Each case had two controls matched for age, gender and date of surgery. Duration of follow-up for a given control had to be at least equal to the time to infection of the corresponding case. Demographic and other clinical data were collected for each patient. RESULTS: Fifty-one cases and 102 controls met the inclusion criteria. Median age was 68 years. Staphylococcal species were identified in 45% of the total number of cases, and 60% of cases with a recovered organism. Univariate analysis identified groin incision, wound complication and wound infection as significant risk factors for PVGI (p<0.005 for all three factors). After adjusting for age and surgery date, multivariate analysis confirmed the statistical significance of groin incision and wound infection as risk factors for PVGI. CONCLUSIONS: This is the first published risk factor analysis that includes statistical evaluation in a case-control study of PVGI. Groin incision, wound complication, and wound infection are significantly associated with developing PVGI. These findings will assist in identifying patients at increased risk of developing subsequent infection. SUMMARY: In order to confirm purported risk factors of prosthetic vascular graft infections (PVGI), a well designed case-control study was conducted at Mayo Clinic, Rochester, MN. Univariate and multivariate analyses of 51 cases and 102 controls identified three statistically significant risk factors for the development of PVGI: groin incision, wound complication, and wound infection.
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CONTEXT: Limited data exist regarding population-based epidemiologic changes in incidence of infective endocarditis (IE). OBJECTIVE: To evaluate temporal trends in the incidence and clinical characteristics of IE. DESIGN, SETTING, AND PATIENTS: Population-based survey using the resources of the Rochester Epidemiology Project of Olmsted County, Minnesota. One hundred seven IE episodes occurred in 102 Olmsted County residents between 1970 and 2000. The modified Duke criteria were used to validate the diagnosis of definite or possible IE. MAIN OUTCOME MEASURES: Incidence of IE, proportion of patients with underlying heart disease, and causative microorganisms and clinical characteristics. RESULTS: Age- and sex-adjusted incidence of IE ranged from 5.0 to 7.0 cases per 100,000 person-years during the study period and did not change significantly over time (P = .42 for trend). Infective endocarditis caused by viridans group streptococci was the most common organism-specific subgroup, with an annual adjusted incidence of 1.7 to 3.5 cases per 100,000; in comparison, IE due to Staphylococcus aureus had an annual adjusted incidence of 1.0 to 2.2 cases per 100,000. No time trend was detected for either pathogen group (P = .63 and P = .66, respectively). An increasing temporal trend was observed in the proportions of prosthetic valve IE cases (P = .09). Among people with underlying heart disease, there was an increasing temporal trend in mitral valve prolapse (P = .04) and a decreasing trend in rheumatic heart disease (P = .08). However, the absolute numbers were small. There was no time trend in rates of valve surgery or 6-month mortality during the study period (P = .97 and P = .59, respectively). CONCLUSIONS: In this community-based temporal trend study, we found no substantial change in the incidence of IE over the past 3 decades. Viridans group streptococci continue to outnumber S aureus as the most common causative organisms of IE in this population.
BACKGROUND: Despite advances in medical, surgical, and critical care interventions, infective endocarditis remains a disease that is associated with considerable morbidity and mortality. The continuing evolution of antimicrobial resistance among common pathogens that cause infective endocarditis creates additional therapeutic issues for physicians to manage in this potentially life-threatening illness. METHODS AND RESULTS: This work represents the third iteration of an infective endocarditis "treatment" document developed by the American Heart Association under the auspices of the Committee on Rheumatic Fever, Endocarditis, and Kawasaki Disease, Council on Cardiovascular Disease of the Young. It updates recommendations for diagnosis, treatment, and management of complications of infective endocarditis. A multidisciplinary committee of experts drafted this document to assist physicians in the evolving care of patients with infective endocarditis in the new millennium. This extensive document is accompanied by an executive summary that covers the key points of the diagnosis, antimicrobial therapy, and management of infective endocarditis. For the first time, an evidence-based scoring system that is used by the American College of Cardiology and the American Heart Association was applied to treatment recommendations. Tables also have been included that provide input on the use of echocardiography during diagnosis and treatment of infective endocarditis, evaluation and treatment of culture-negative endocarditis, and short-term and long-term management of patients during and after completion of antimicrobial treatment. To assist physicians who care for children, pediatric dosing was added to each treatment regimen. CONCLUSIONS: The recommendations outlined in this update should assist physicians in all aspects of patient care in the diagnosis, medical and surgical treatment, and follow-up of infective endocarditis, as well as management of associated complications. Clinical variability and complexity in infective endocarditis, however, dictate that these guidelines be used to support and not supplant physician-directed decisions in individual patient management.
The efficacy and renal safety of amphotericin B lipid complex (ABLC) injection were assessed in 106 patients with cryptococcal infection. Eighty-three patients (78%) had a central nervous system (CNS) infection. Of these patients, 20 initiated azole therapy concomitantly with ABLC therapy, and 7 had received prior azole therapy, which continued during administration of ABLC. Clinical response (cured or improved) was achieved in 67 (66%) of 101 patients whose results could be evaluated. Response rates were 65% (51/78) for patients with a CNS infection and 70% (16/23) for patients without a CNS infection. The response rate for patients with HIV infection was 58% (30/52). Response rates were 56% (19/34) for patients who were refractory to prior antifungal therapy, 65% (11/17) for patients who were intolerant of prior antifungal therapy, 60% (3/5) for patients with underlying renal disease who received prior antifungal therapy, 76% (25/33) for patients with underlying renal disease who did not receive prior antifungal therapy, and 73% (8/11) for patients with no renal disease who did not receive prior antifungal therapy. A mean serum creatinine level decrease of 0.02 mg/dL occurred. ABLC was an effective treatment for cryptococcal infection in immunocompromised patients.
BACKGROUND: Necrotizing fasciitis is an uncommon disease with high morbidity and mortality rates. Little is known about the role of histopathologic examination in disease prognosis. METHODS: A retrospective study was conducted to determine what correlations, if any, exist between the histopathologic features of resected tissue in patients with necrotizing fasciitis and clinical outcome. RESULTS: Eighty-two cases of necrotizing fasciitis that occurred between January 1990 and December 2002 were identified. Histopathologic findings were available for review in 63 cases. A novel histopathologic classification scheme, based on hematoxylin-eosin and Gram stain results, was developed. The classification scheme included 3 stages: stage I, characterized by an intense neutrophilic response and an absence of bacteria in infected tissue; stage II, characterized by the presence of a moderate-to-severe neutrophilic response and positive Gram stain results or by minimal to absent neutrophilic response with a negative Gram stain result; and stage III, characterized by the presence of few or no polymorphonuclear leukocytes and a Gram stain result positive for bacteria during histopathologic examination. Patients with stage I findings had a significantly lower risk of death than patients with stage III findings (7.1% vs. 47%; odds ratio [OR], 0.1; 95% confidence interval [CI], 0.01-0.8; P=.03). Patients with stage II findings had a significantly lower mortality rate than patients with stage III findings (14.2% vs. 47%; OR, 0.2; 95% CI, 0.04-0.9; P=.04). Due to the small number of deaths (n=11) in patients for whom histopathologic examination of resected tissue was performed, multivariate analysis was not done. CONCLUSIONS: Results of this study suggest that histopathologic findings may correlate with clinical outcome in cases of necrotizing fasciitis. Because the histopathologic scheme is based on results of commonly available stains, it could be easily adopted for use in other institutions that could further evaluate its usefulness as a prognostic tool.