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Biomedical subjects

D L Longworth

Publications and source records attributed to D L Longworth.

At least 37 records · Page 2Linked to original sources

Cytomegalovirus infection is a risk factor for invasive aspergillosis in lung transplant recipients.

Invasive aspergillosis (IA) remains a major cause of morbidity and mortality following solid organ transplantation. To assess the incidence of IA following lung transplantation and to identify risk factors for its occurrence, we performed a case-control study involving 101 patients undergoing lung transplantation at our institution from 1990 to 1995 and reviewed the findings. Fourteen patients (14%) developed IA. The mean time from transplantation to diagnosis was 15 months. Nine patients died; the mean time to death from diagnosis was 13 days. Risk factors associated with developing IA included concomitant cytomegalovirus (CMV) pneumonia or viremia and culture isolation of Aspergillus species from a respiratory tract specimen after lung transplantation. Optimal strategies to prevent IA in lung transplant recipients remain to be determined, but prevention of aspergillus airway colonization and CMV viremia and disease after transplantation may be important targets for prophylactic interventions.

Aspergillosis↗

Routine cultures of bone marrow and peripheral stem cell harvests: clinical impact, cost analysis, and review.

The American Association of Blood Banks requires routine culture of hematopoietic progenitor cells prior to bone marrow transplantation. We sought to evaluate the cost of that requirement and the incidence and clinical significance of positive cultures. We performed a retrospective analysis of transplant recipients at our institution. Of the 605 patients for whom 1,934 consecutive cultures of harvests were done between December 1992 and February 1996, 11 had positive cultures. Six patients received a culture-positive harvest with no adverse effects. The total cost of cultures was $35,660 (U.S. $). In North America and worldwide in 1995, routine culture of harvests would have prevented 7.9 and 18.9 cases of bacteremia, respectively, at a cost of $95,000 per bacteremia prevented. We conclude that routine culture of hematopoietic progenitor cells yields low rates of positivity and that infusion of contaminated harvests rarely results in clinically adverse outcomes.

Adult↗

Incidence and risk of developing fungal prosthetic valve endocarditis after nosocomial candidemia.

PURPOSE: To determine the incidence of prosthetic valve endocarditis (PVE) in fungemic patients with prosthetic heart valves (PHV), estimate risk of subsequent PVE, and describe risk factors and diagnostic and therapeutic management issues in such patients. PATIENTS AND METHODS: This is a retrospective chart review in a 1,100-bed tertiary referral center with an active cardiothoracic surgical service. Forty-four patients with PHVs developed nosocomial fungemia between January 1985 and April 1995. RESULTS: Of 44 patients, 33 never developed evidence of PVE (group 1), 7 (16%) had evidence of PVE at the time of candidemia (group 2), and 4 (9%) developed PVE a mean of 232 days after candidemia (group 3). Predisposing factors including intravascular lines, prior antibiotic therapy, and an identifiable portal of entry for fungemia were common in group 1 but not group 2. Candidemia occurred significantly later after PHV surgery in group 2 (mean 270 days) as compared to groups 1 and 3 (means 48 and 15.5 days, respectively; P = 0.02). Ten of 11 patients with Candida PVE (group 2 and 3) were treated with amphotericin B and valve replacement. Three relapses after combined therapy were documented in two patients. Mortality was significantly higher for patients without Candida PVE (group 1) as compared to patients with Candida PVE (groups 2 and 3) at 1 month (53% vs 9%), 2 months (69% vs 20%) and 1 year (83% vs 25%) after candidemia. CONCLUSIONS: Patients with prosthetic heart valves who develop nosocomial candidemia are at notable risk of either having or developing Candida PVE months or years later. Late onset candidemia and lack of an identifiable portal of entry should heighten concern about Candida PVE in such patients.

Candidiasis↗

Coagulase-negative staphylococcal sternal wound infections after open heart operations.

BACKGROUND: Coagulase-negative staphylococci are commonly isolated from wounds of patients after median sternotomy; however, the epidemiology of these infections is poorly described and the morbidity, mortality, and cost of care remain undefined. METHODS: Retrospectively, we studied all patients with sternal wound infections attributable to coagulase-negative staphylococci after 22,180 open heart procedures performed at the Cleveland Clinic between January 1, 1988, and December 31, 1994 (84 months). In an assessment of potential risk factors for sternal wound infections caused by coagulase-negative staphylococci, 17 patients with coagulase-negative staphylococcal sternal wound infections were compared with 29 patients who underwent open heart operations without subsequent sternal wound infections, as well as with another 22 patients in whom sternal wound infections attributable to other pathogens developed. RESULTS: A total of 436 sternal wound infections were identified (19 per 1,000 procedures), of which 100 (23%) were attributable to coagulase-negative staphylococci (4.5 per 1,000). Fifty-six percent of coagulase-negative staphylococcal sternal wound infections were superficial, 27% were deep, and 17% represented mediastinitis; 14% of patients had a concomitant secondary bloodstream infection. Ninety-two percent of coagulase-negative staphylococcal isolates were methicillin resistant. The mean interval from operation to onset of infection was 24 days (range, 4 to 388 days), and most patients had purulent discharge from the chest wound, fever, and leukocytosis. Adverse outcomes included reexploration (39%), flap operation (12%), and sternectomy (5%); 89% required parenteral antibiotics for a mean of 22 days. This resulted in 2,600 additional hospital days, with an average additional direct cost per case of $20,000. In both case-control studies, insulin-dependent diabetes mellitus was the only risk factor significantly associated with sternal wound infections attributable to coagulase-negative staphylococci (p value = 0.02 by two-tailed Fisher's exact test). CONCLUSIONS: Sternal wound infections attributable to coagulase-negative staphylococci had a substantial impact on cardiothoracic surgery-related morbidity.

Anti-Bacterial Agents↗

Oral disease burden in patients undergoing prosthetic heart valve implantation.

BACKGROUND: Valvular heart disease predisposing to endocarditis and requiring prosthetic valve implantation is common among the elderly. Spontaneous bacteremias associated with acute or chronic oral/odontogenic infections may represent a far greater cumulative risk for the development of endocarditis than do occasional health care procedures administered in a professional setting. METHODS: To determine the oral disease burden in patients undergoing mechanical or bioprosthetic heart valve implantation, we performed a comprehensive clinical and radiographic regional examination on 156 consecutive patients, with emphasis on identifying acute and chronic oral/odontogenic infections and conditions. RESULTS: The mean number of remaining teeth in the cohort was 19.32; of these, 1.07 were carious, involving a mean number of 2.51 tooth surfaces. In addition, 15.38% of the patients had evidence of acute or chronic periapical abscesses, and 43.6% of the patients had moderate to advanced periodontitis. CONCLUSIONS: In view of the substantial morbidity and mortality associated with prosthetic valve endocarditis and based upon the high incidence of dental disease identified in patients undergoing valvular operations, routine preoperative dental assessment should be deemed a "medical necessity" by third-party payors. Appropriate therapeutic intervention should be initiated whenever possible before valve implantation.

Adult↗

Lactobacillus bacteremia and endocarditis: review of 45 cases.

Lactobacilli are part of normal gastrointestinal and genitourinary flora but are an uncommon cause of bacteremia. We reviewed the cases of 45 patients with clinically significant lactobacillus bacteremia occurring over 15 years. Underlying conditions were common, including cancer (40%), recent surgery (38%), and diabetes mellitus (27%). Twenty-two patients were in the intensive care unit at the time of onset of lactobacillus bacteremia. Eleven of the 45 patients were receiving immunosuppressive therapy, 11 were receiving total parenteral nutrition, and 23 had received antibiotics without activity against Lactobacillus prior to the occurrence of bacteremia. Bacteremia was polymicrobial in 27 patients and developed during hospitalization in 39. Thirty-one patients died, but only one death was attributable to lactobacillus bacteremia. Lactobacilli are relatively avirulent pathogens that produce bacteremia in patients with serious underlying illnesses, many of whom have received prior antibiotic therapy that may select out for the organism. While rarely fatal in itself, lactobacillus bacteremia identifies patients with serious and rapidly fatal illness.

Adult↗

Fungal prosthetic valve endocarditis in 16 patients. An 11-year experience in a tertiary care hospital.

Fungal prosthetic valve endocarditis (PVE) is an infrequent but serious complication of valve replacement surgery. To examine its long-term outcome, we retrospectively studied 16 patients with 19 episodes of definite fungal PVE. The mean age was 51 years (range, 27-71 yr). Onset of fungal PVE ranged from 8 days to 3.4 years after valve replacement. Candida albicans was the most common (56%) pathogen isolated. A portal of entry was identified in only 25% of the patients; the presence of intravascular catheters (50%) and prior bacterial endocarditis (38%) were leading predisposing factors. Fever (83%) was the most consistent clinical finding. Potentially serious embolic events, particularly strokes (32%), were common at presentation. Transesophageal echocardiography (sensitivity = 100%) was more useful than transthoracic echocardiography (sensitivity = 60%) in detecting lesions due to fungal PVE. Combined valve replacement surgery and amphotericin B (mean total dose of 1.8 g) in 15 patients resulted in an 87% in-hospital survival and 67% overall survival with a mean follow-up of 4.5 years (range, 5 mo to 16 yr). Two patients had 3 late relapses of fungal PVE up to 9 years after the preceding episode. Each relapse was treated with repeat valve replacement and amphotericin B; in addition, oral azole was utilized for chronic suppression, although the efficacy of this strategy remains unproven. Because of the possibility of relapse, long-term follow-up is essential even after surgical and prolonged antifungal therapy.

Adult↗

The emergence of Neisseria gonorrhoeae with decreased susceptibility to ciprofloxacin in Cleveland, Ohio: epidemiology and risk factors.

BACKGROUND: Until 1992, almost all strains of Neisseria gonorrhoeae that had been tested in the United States were susceptible to fluoroquinolones, including ciprofloxacin. However, among men with urethral gonococcal infections who attended one sexually transmitted disease clinic in Cleveland, Ohio, the prevalence of gonococci with decreased susceptibility to ciprofloxacin increased from 2% in 1991 to 16% in 1994. OBJECTIVE: To describe the emergence of and risk factors for gonococcal urethritis caused by gonococci with decreased susceptibility to ciprofloxacin. Resistance to ciprofloxacin was considered to be decreased if the mean inhibitory concentration was at least 0.12 microgram/mL, and was less than or equal to 0.25 microgram/mL; this definition did not equate with the definition of clinical resistance. DESIGN: Case-control study. SETTING: An urban sexually transmitted disease clinic. PARTICIPANTS: 51 case-patients and 106 controls. MEASUREMENTS: Pulsed-field gel electrophoresis was used to identify individual genotypes of ciprofloxacin-resistant and ciprofloxacin-susceptible isolates. RESULTS: 55 of the 746 isolates of N. gonorrhoeae that were tested (7.4%) had decreased susceptibility to ciprofloxacin, and the prevalence of N. gonorrhoeae with decreased susceptibility significantly increased during the study period. Case-patients were significantly less likely to have gram-negative diplococci seen on microscopic examination of urethral discharge (P < or = 0.01) and were less likely to be treated for gonococcal urethritis than were controls (P < or = 0.001). Molecular typing suggested the spread of a single genotype of N. gonorrhoeae. CONCLUSIONS: Strains of gonococci with decreased susceptibility to ciprofloxacin appear to have become endemic in Cleveland, Ohio. The clinical significance of these isolates is not clear, but the potential for the emergence of clinically important resistance may preclude the use of fluoroquinolones as an alternative treatment for uncomplicated gonorrhea.

Anti-Infective Agents↗

Impact of chlorhexidine-silver sulfadiazine-impregnated central venous catheters on in vitro quantitation of catheter-associated bacteria.

To assess the impact of the antiseptic effects of silver sulfadiazine-chlorhexidine-impregnated central venous catheters on catheter culture systems, a series of in vitro experiments was performed. Segments of antiseptic and non-antiseptic-impregnated catheters were sonicated in thioglycolate broth and removed. After the addition of 10(3) CFU of Staphylococcus epidermidis per ml, aliquots of catheter-exposed broth were subcultured onto blood agar at 15-min intervals. Decreased mean colony counts were noted at 45 min for broth exposed to antiseptic-impregnated catheters compared with the colony counts for broth exposed to non-antiseptic-impregnated catheters (170 versus 540 CFU/ml). These effects, which were also demonstrated by the roll-plate method, were abrogated by the use of medium containing inhibitors of silver sulfadiazine and chlorhexidine. To assess the duration of the antiseptic effects, catheter segments were suspended for up to 14 days in phosphate-buffered saline, incubated with 10(6) CFU of S. epidermidis per ml, and cultured. Inhibition of bacterial growth by antiseptic-impregnated catheters disappeared after 14 days. These studies suggest that antiseptic compounds elute from catheters during broth- and solid medium-based culturing processes, making necessary the addition of inhibitors of these compounds in culture media. They further suggest that the antimicrobial effects of antiseptic-impregnated catheters wane within several days of placement.

Anti-Infective Agents, Local↗

Early infectious complications in autologous bone marrow transplantation: a review of 219 patients.

The objective of this study was to define the incidence, type and timing of early infectious complications, occurring within the first 30 days, in autologous bone marrow transplant (autoBMT) recipients over a 45-month period, and in addition to assess the effects of growth factors and primed peripheral blood progenitor cells on the rate of infectious complications. The paper describes a retrospective and observational study, carried out at the bone marrow transplantation unit at a tertiary referral center. The subjects were two hundred and nineteen patients who underwent autologous bone marrow transplantation for a variety of indications from April 1989 to December 1992. The median duration of neutropenia after autologous bone marrow transplantation was 12 days. There was a direct correlation between the duration of neutropenia and the incidence of infectious complications. The overall incidence of infections and isolated febrile episodes was 35%. Septicemia occurred in 7.8% of patients, pneumonia in 2.7%, skin infection in 1.8%, other infections in 2.7% and isolated febrile episodes in 20.1%. Viridans streptococci were the most common cause of septicemia. Invasive fungal infections occurred in only 2.3% of patients. There were no documented viral infections. The use of growth factors and primed peripheral blood progenitor cells was associated with a shorter duration of neutropenia; a decrease in the overall incidence of infections, particularly septicemia and fungal infections; a shorter length of stay in the hospital and a lower mortality rate in the first 30 days after transplantation. We found a lower incidence of bacterial and fungal infections compared to previous studies. The critical factor associated with the occurrence of any early infection was the duration of neutropenia, which was significantly shortened by the use of growth factors and peripheral blood progenitor cells. Septicemia was uncommon in our population and viridans streptococci were the most common bloodstream isolates.

Adolescent↗

Drug-resistant malaria in children and in travelers.

Malaria remains a significant cause of childhood morbidity and mortality worldwide. Drug resistance in Plasmodium falciparum has become widespread in the past 30 years, and in some parts of the world multidrug resistance is common. Chloroquine resistance in Plasmodium vivax has recently been recognized in Indonesia. The mechanisms of drug resistance have been defined for the antifolate antimalarial agents but remain incompletely understood for the quinolines. Judicious use of antimalarial compounds will be essential to prevent the emergence and spread of further drug resistance. The history, geographic distribution, and mechanisms of drug resistance are reviewed, together with current recommendations regarding prophylaxis and therapy.

Animals↗

Deep tissue infections caused by Scopulariopsis brevicaulis: report of a case of prosthetic valve endocarditis and review.

Scopulariopsis brevicaulis is a saprophytic fungus that commonly causes onychomycosis but rarely causes deep tissue infection. To the best of our knowledge, this is the first reported case of endocarditis caused by S. brevicaulis. The infection persisted despite two aortic valve replacements, debridement, and prolonged therapy with several antifungal agents. The patient eventually died due to an acute myocardial infarction caused by ongoing prosthetic valve endocarditis. We review case reports of deep tissue infections due to Scopulariopsis species.

Aged↗

Viral pulmonary infections in thoracic and cardiovascular surgery.

Viral respiratory infections are uncommon causes of pulmonary infiltrates in immunocompetent patients who undergo cardiothoracic surgery. In winter months, however, influenza can be acquired in the community preoperatively or in the hospital setting. The recognition of influenza cases is essential to prevent nosocomial transmission. Respiratory syncytial virus is also an important pulmonary pathogen in pediatric patients who undergo cardiothoracic surgery and may produce serious disease in children with underlying pulmonary or congenital heart disease. Viral infections of the respiratory tract are important causes of morbidity and mortality in heart and lung transplant recipients, especially cytomegalovirus (CMV). Other herpes viruses such as varicella zoster virus and herpes simplex virus may also occasionally involve the lung. Epstein-Barr virus has been incriminated in the pathogenesis of post-transplant lymphoproliferative disease, an uncommon but severe complication of transplantation. Except for Epstein-Barr virus, effective therapy exists for CMV and the other herpes viruses. Prophylaxis with ganciclovir is effective in preventing serious CMV infections in seropositive heart transplant recipients. However, better strategies are needed to prevent primary CMV infection in these patients.

Adenovirus Infections, Human↗