Fatal Serratia marcescens meningitis and myocarditis in a patient with an indwelling urinary catheter.
Serratia marcescens is commonly isolated from the urine of patients with an indwelling urinary catheter and in the absence of symptoms is often regarded as a contaminant. A case of fatal Serratia marcescens septicaemia with meningitis, brain abscesses, and myocarditis discovered at necropsy is described. The patient was an 83 year old man with an indwelling urinary catheter who suffered from several chronic medical conditions and from whose urine Serratia marcescens was isolated at the time of catheterisation. Serratia marcescens can be a virulent pathogen in particular groups of patients and when assessing its significance in catheter urine specimens, consideration should be given to recognised risk factors such as old age, previous antibiotic treatment, and underlying chronic or debilitating disease, even in the absence of clinical symptoms. (+info)
Role of schools in the transmission of measles in rural Senegal: implications for measles control in developing countries.
Patterns of measles transmission at school and at home were studied in 1995 in a rural area of Senegal with a high level of vaccination coverage. Among 209 case children with a median age of 8 years, there were no deaths, although the case fatality ratio has previously been 6-7% in this area. Forty percent of the case children had been vaccinated against measles; the proportion of vaccinated children was higher among secondary cases (47%) than among index cases (33%) (prevalence ratio = 1.36, 95% confidence interval (CI) 1.04-1.76). Vaccinated index cases may have been less infectious than unvaccinated index cases, since they produced fewer clinical cases among exposed children (relative risk = 0.55, 95% CI 0.29-1.04). The secondary attack rate was lower in the schools than in the homes (relative risk = 0.31, 95% CI 0.20-0.49). The school outbreaks were protracted, with 4-5 generations of cases being seen in the two larger schools. Vaccine efficacy was found to be 57% (95% CI -23 to 85) in the schools and 74% (95% CI 62-82) in the residential compounds. Measles infection resulted in a mean of 3.8 days of absenteeism per case, though this did not appear to have an impact on the children's grades. Among the index cases, 56% of children were probably infected by neighbors in the community, and 7% were probably infected at health centers, 13% outside the community, and 24% in one of the three schools which had outbreaks during the epidemic. However, most of the school-related cases occurred at the beginning and therefore contributed to the general propagation of the epidemic. To prevent school outbreaks, it may be necessary to require vaccination prior to school entry and to revaccinate children in individual schools upon detection of cases of measles. Multidose measles vaccination schedules will be necessary to control measles in developing countries. (+info)
Risk factors for nosocomial bloodstream infections due to Acinetobacter baumannii: a case-control study of adult burn patients.
Risk factors for Acinetobacter baumannii bloodstream infection (BSI) were studied in patients with severe thermal injury in a burn intensive care unit where A. baumannii was endemic. Of 367 patients hospitalized for severe thermal injury during the study period, 29 patients with nosocomial A. baumannii BSI were identified (attack rate, 7.9%). Cases were compared with 58 matched controls without A. baumannii BSI. The overall mortality rate was 31% among cases and 14% among controls; only two deaths (7%) were considered directly related to A. baumannii BSI. Molecular typing of A. baumannii blood isolates by means of randomly amplified polymorphic DNA analysis and pulsed-field gel electrophoresis revealed the presence of three different strain types. Multivariate analysis showed that female gender (P = .027), total body surface area burn of > 50% (P = .016), prior nosocomial colonization with A. baumannii at a distant site (P = .0002), and use of hydrotherapy (P = .037) were independently associated with the acquisition of A. baumannii BSI in burn patients. These data underscore the need for effective infection control measures for this emerging nosocomial problem. (+info)
Infective endocarditis due to Staphylococcus aureus: 59 prospectively identified cases with follow-up.
Fifty-nine consecutive patients with definite Staphylococcus aureus infective endocarditis (IE) by the Duke criteria were prospectively identified at our hospital over a 3-year period. Twenty-seven (45.8%) of the 59 patients had hospital-acquired S. aureus bacteremia. The presumed source of infection was an intravascular device in 50.8% of patients. Transthoracic echocardiography (TTE) revealed evidence of IE in 20 patients (33.9%), whereas transesophageal echocardiography (TEE) revealed evidence of IE in 48 patients (81.4%). The outcome for patients was strongly associated with echocardiographic findings: 13 (68.4%) of 19 patients with vegetations visualized by TTE had an embolic event or died of their infection vs. five (16.7%) of 30 patients whose vegetations were visualized only by TEE (P < .01). Most patients with S. aureus IE developed their infection as a consequence of a nosocomial or intravascular device-related infection. TEE established the diagnosis of S. aureus IE in many instances when TTE was nondiagnostic. Visualization of vegetations by TTE may provide prognostic information for patients with S. aureus IE. (+info)
Optimizing aminoglycoside therapy for nosocomial pneumonia caused by gram-negative bacteria.
Nosocomial pneumonia is a notable cause of morbidity and mortality and leads to increases in lengths of hospital stays and institutional expenditures. Aminoglycosides are used to treat patients with these infections, but few data on the doses and schedules required to achieve optimal therapeutic outcomes exist. We analyzed aminoglycoside treatment data for 78 patients with nosocomial pneumonia to determine if optimization of aminoglycoside pharmacodynamic parameters results in a more rapid therapeutic response (defined by outcome and days to leukocyte count resolution and temperature resolution). Cox proportional hazards, Classification and Regression Tree (CART), and logistic regression analyses were applied to the data. By all analyses, the first measured maximum concentration of drug in serum (Cmax)/MIC predicted days to temperature resolution and the second measured Cmax/MIC predicted days to leukocyte count resolution. For days to temperature resolution and leukocyte count resolution, CART analyses produced breakpoints, with an 89% success rate at 7 days of therapy for a Cmax/MIC of > 4.7 and an 86% success rate at 7 days of therapy for a Cmax/MIC of > 4.5, respectively. Logistic regression analyses predicted a 90% probability of temperature resolution and leukocyte count resolution by day 7 if a Cmax/MIC of > or = 10 is achieved within the first 48 h of aminoglycoside therapy. Aggressive aminoglycoside dosing immediately followed by individualized pharmacokinetic monitoring would ensure that Cmax/MIC targets are achieved early in therapy. This would increase the probability of a rapid therapeutic response for pneumonia caused by gram-negative bacteria and potentially decreasing durations of parenteral antibiotic therapy, lengths of hospitalization, and institutional expenditures, a situation in which both the patient and the institution benefit. (+info)
Efficacy of sulbactam alone and in combination with ampicillin in nosocomial infections caused by multiresistant Acinetobacter baumannii.
From March 1995 to March 1997, sulbactam was prospectively evaluated in patients with non-life-threatening multiresistant Acinetobacter baumannii infections. During this period, 47 patients were treated with sulbactam; of them, five were excluded because they had received < or =48 h of sulbactam therapy. A total of 42 patients, 27 males and 15 females with a mean age of 60+/-15 years, were finally evaluated. Infections were as follows: surgical wound, 19; tracheobronchitis, 12; urinary tract, 7; catheter-related bacteraemia, 2; and pneumonia, 2. Eighteen patients received intravenous sulbactam alone (1 g every 8 h) and 24 patients received intravenous sulbactam/ampicillin (1 g:2 g every 8 h) with no major adverse effects. Of the 42 patients, 39 improved or were cured and showed A. baumannii eradication and one patient had persistence of wound infection after 8 days of sulbactam/ampicillin requiring surgical debridement. Two patients died after 3 days of therapy (one of the deaths was attributable to A. baumannii infection). The in-vitro activity of the sulbactam/ampicillin combination was by virtue of the antimicrobial activity exhibited by sulbactam. Killing curves showed that sulbactam was bacteriostatic; no synergy was observed between ampicillin and sulbactam. Our results indicate that sulbactam may prove effective for non-life-threatening A. baumannii infections. Its role in the treatment of severe infections is unknown. However, the current formulation of sulbactam alone may allow its use at higher doses and provide new potential synergic combinations, particularly for those infections by A. baumannii resistant to imipenem. (+info)
Transmission dynamics of epidemic methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci in England and Wales.
A simple epidemiological framework for the analysis of the transmission dynamics of hospital outbreaks of epidemic methicillin-resistant Staphylococcus aureus (EMRSA) and vancomycin-resistant enterococci (VRE) in hospitals in England and Wales is presented. Epidemic strains EMRSA-15 and EMRSA-16 are becoming endemic in hospitals in the United Kingdom, and theory predicts that EMRSA-15 and EMRSA-16 will reach respective endemic levels of 158 (95% confidence interval [CI], 143-173) and 116 (95% CI, 109-123) affected hospitals with stochastic fluctuations of up to 30 hospitals in each case. An epidemic of VRE is still at an early stage, and the incidence of hospitals newly affected by VRE is growing exponentially at a rate r=0.51/year (95% CI, 0.48-0.54). The likely impact of introducing surveillance policies if action is taken sufficiently early is estimated. Finally, the role of heterogeneity in hospital size is considered: "Super-spreader hospitals" may increase transmission by 40%-132% above the expected mean. (+info)
Serum is more suitable than whole blood for diagnosis of systemic candidiasis by nested PCR.
PCR assays for the diagnosis of systemic candidiasis can be performed either on serum or on whole blood, but results obtained with the two kinds of samples have never been formally compared. Thus we designed a nested PCR assay in which five specific inner pairs of primers were used to amplify specific targets on the rRNA genes of Candida albicans, C. tropicalis, C. parapsilosis, C. krusei, and C. glabrata. In vitro, the lower limit of detection of each nested PCR assay was 1 fg of purified DNA from the corresponding Candida species. In rabbits with candidemia of 120 minutes' duration following intravenous (i.v.) injection of 10(8) CFU of C. albicans, the sensitivities of the PCR in serum and whole blood were not significantly different (93 versus 86%). In other rabbits, injected with only 10(5) CFU of C. albicans, detection of candidemia by culture was possible for only 1 min, whereas DNA could be detected by PCR in whole blood and in serum for 15 and 150 min, respectively. PCR was more often positive in serum than in whole blood in 40 culture-negative samples (27 versus 7%; P < 0.05%). Lastly, experiments with rabbits injected i.v. with 20 or 200 microgram of purified C. albicans DNA showed that PCRs were positive in serum from 30 to at least 120 min after injection, suggesting that the clearance of free DNA is slow. These results suggest that serum is the sample of choice, which should be used preferentially over whole blood for the diagnosis of systemic candidiasis by PCR. (+info)