Bernard Rudensky

Cost-Effectiveness of Blood Cultures for Adult Patients with Cellulitis

To assess the cost-effectiveness of blood cultures for patients with cellulitis, a retrospective review was conducted of clinical and microbiological data for all 757 patients admitted to a medical center because of community-acquired cellulitis during a 41-month period. Blood cultures were performed for 553 patients (73%); there were a total of 710 blood samples (i.e., a mean of 1.3 cultures were performed per patient). In only 11 cases (2.0%) was a significant patient-specific microbial strain isolated, mainly beta-hemolytic streptococci (8 patients [73%]). An organism that was considered a contaminant was isolated from an additional 20 culture bottles (3. 6%). The cost of laboratory workup of the 710 culture sets was

The risk of vascular infection in adult patients with nontyphi Salmonella bacteremia

36, 050. Isolation of streptococci led to a change from empirical treatment with cefazolin to penicillin therapy for 8 patients. All patients recovered. In conclusion, the yield of blood cultures is very low, has a marginal impact on clinical management, and does not appear to be cost-effective for most patients with cellulitis.

Procalcitonin in preterm infants during the first few days of life: introducing an age related nomogram

Infections due to Salmonella are common, and their incidence appears to be increasing in many countries (1,2). Although S. typhi and S. paratyphi infect only humans, nontyphoidal Salmonella are widely spread in nature and are commonly associated with certain animals, eg, chickens. In humans, nontyphoidal Salmonella infections are most often associated with contaminated food products (3). Salmonellosis may manifest in five different clinical forms, including asymptomatic chronic carrier state, gastroenteritis, enteric fever, bacteremia, and extraintestinal localized complications of which endovascular infection is one of the most serious (4). Almost every arterial site in the body may become involved (5–7); however, infections of the aorta appear to be the most frequent (8 –10). There remain substantial questions regarding the relative frequency of vascular complications in Salmonella bacteremia, the optimal diagnostic approach, and the subsequent therapeutic management. We reviewed all patients with Salmonella bacteremia from a 10-year period (1990 to 1999) to determine the frequency of vascular complications, describe clinical details of 3 patients with Salmonella mycotic aneurysm, and review diagnostic methods and treatment.

Carriage rate of carbapenem-resistant Klebsiella pneumoniae in hospitalised patients during a national outbreak

Objective: To determine normal concentrations of procalcitonin in preterm infants shortly after birth and to assess its accuracy in detecting bacterial infection. Methods: Blood samples of 100 preterm infants were prospectively drawn during the first 4 days of life for determination of procalcitonin concentration. Infants were classified into four groups according to their sepsis status. Results: Mean (SD) gestational age and birth weight were 32 (2.9) weeks and 1682 (500) g respectively. A total of 283 procalcitonin concentrations from healthy infants were plotted to construct nomograms of physiologically raised procalcitonin concentration after birth, stratified by two groups to 24–30 and 31–36 weeks gestation. The peak 95th centile procalcitonin concentration was plotted at 28 hours of age; values return to normal after 4 days of life. Only 12 infants were infected, and 13 of their 16 procalcitonin concentrations after birth were higher than the 95th centile, whereas samples taken at birth were lower. In a multivariable analysis, gestational age, premature rupture of membrane, and sepsis status influenced procalcitonin concentration independently, but maternal infection status did not. Conclusions: The suggested neonatal nomograms of preterm infants are different from those of term infants. Procalcitonin concentrations exceeding the 95th centile may be helpful in detecting congenital infection, but not at birth.

Survey of hematological aspects of Gaucher disease

During a national outbreak of carbapenem-resistant Klebsiella pneumoniae (CRKP) in Israel, we conducted a point prevalence survey to determine the extent of asymptomatic carriage. Subsequently, a retrospective case-control study was done, comparing carriers of CRKP with non-carriers, in order to detect risk factors for carriage. Oral, perianal and rectal swabs were obtained from all hospitalised eligible and consenting patients. Selective media for carbapenem-resistant Gram-negative bacteria were used and pulsed-field gel electrophoresis (PFGE) helped to determine clonal source. Culture was obtained from 298 patients. Sixteen (5.4%) were carriers of CRKP, with a higher carriage rate in medical and surgical wards. Only 18% of carriers were treated with any carbapenem prior to the survey. Five of the 16 carriers had a positive clinical specimen for CRKP, hence a clinical infection versus asymptomatic carriage ratio of 1:3. The rectum was the most sensitive site sampled, detecting 15/16 carriers, and the overall sensitivity of the method was 94% with a negative predictive value of 99.6%. In a multivariate analysis of risk factors for CRKP carriage, three variables were significantly related to carriage state: diaper use, longer duration of hospital stay and vancomycin use. PFGE demonstrated that all 16 isolates were identical, confirming clonal origin. A point prevalence survey performed at a single medical centre during an outbreak of CRKP demonstrated a carriage rate of 5.4%. The clonal origin of these isolates suggests that strict adherence to isolation procedure may contain this outbreak.

Changing Epidemiology of Infective Endocarditis: A Retrospective Survey of 108 Cases, 1990–1999

Abstract Hematologists have classically been the treating physicians of patients with Gaucher disease, and today, despite both specific and symptomatic therapeutic advances, they remain at the forefront of specialists to whom patients with Gaucher disease present. It is therefore appropriate to review that has changed and what has remained the same in hematological signs and symptoms of the disease in the decade and a half since therapy has become available.

The prevalence and nosocomial acquisition of Clostridium difficile in elderly hospitalized patients.

Abstract.The aim of this study was to report the experience with infective endocarditis over the past decade, describe the changing clinical and epidemiological features of the disease, and attempt to determine the optimal number of blood culture sets required for diagnosis. All cases diagnosed during a 10-year period were reviewed clinically and microbiologically. In addition, a retrospective assessment of blood culture data was performed. From the period 1990–1999, 108 cases that met the von Reyn or Dukes criteria were recorded. The major underlying cardiac condition was the presence of a prosthetic valve (n=33 patients, 31%). Among patients with native valves, nonrheumatic valvular heart disease of the elderly was the most common underlying factor (n=19 patients, 25%). Overall, 13 patients (11%) died. Predictors on admission for increased mortality were shortness of breath, age >60 years, time to defervescence, erythrocyturia, hemoglobin level <10 g/dl, and leukocytosis >15,000 (all P<0.05). Analysis of blood culture data showed that the diagnostic yield among groups from whom either only one or more than six blood culture sets were drawn was reduced compared with that among groups from whom between two and five culture sets had been taken. The outcome of endocarditis in this series from a community hospital was much more favorable compared with that reported in surveys from large tertiary centers. Moreover, obtaining more than two or three blood cultures is neither helpful nor cost-effective in the initial assessment of patients with suspected endocarditis.

Adult Patients with Occult Bacteremia Discharged from the Emergency Department: Epidemiological and Clinical Characteristics

Rectal swabs obtained from 10 of 49 chronic-care geriatric patients were positive for Clostridium difficile, for a prevalence rate of 20.4%. Simultaneous sampling of 29 patients in an acute geriatric ward revealed four colonized patients, for a prevalence rate of 13.7%. A prospective study of C. difficile colonization in 100 consecutive patients admitted to an acute geriatric ward was carried out. All patients were sampled upon admission and biweekly during hospitalization. Two patients (2%) were positive on admission, and 12 of the 98 initially negative patients became colonized, representing a nosocomial acquisition rate of 12.2%. A major determinant for C. difficile colonization in asymptomatic patients appears to be length of hospitalization. Previous antibiotic administration was not found to be a significant factor.

The role of procalcitonin as a predictor of nosocomial sepsis in preterm infants

To determine the epidemiological and clinical characteristics of patients who were discharged from the emergency department (ED) and subsequently proved to have bacteremia, we prospectively assessed all patients examined in the ED during an 18-month period from whose blood cultures a significant organism was isolated. Discharged patients were contacted and reevaluated. Two case-control studies were conducted, in which each study patient was matched with a total of 4 control patients. During the study period, 46,336 patients were examined in the ED; 78% were adults and 22% were children. Blood cultures were performed for 25% of the adult patients and for 44% of the children. Although the occurrence of occult bacteremia in patients who were discharged from the ED is 3.7 times more common in children than in adults, the absolute numbers of discharged adults and children with occult bacteremia are similar. Careful clinical assessment will not prevent discharge of some of these patients; however, these patients in general do well and can be safely recalled for reevaluation and complementation of therapy.

Treatment regimens for Helicobacter pylori infection in children: is in vitro susceptibility testing helpful?

Aim: To assess the role of procalcitonin in detecting nosocomial sepsis in preterm infants, after the onset of clinical symptoms. Subjects: 100 preterm infants, 24–36 wk of gestation, were followed from the age of 3 d until discharge. Procalcitonin and C‐reactive protein (CRP) levels were measured within 3 d of sepsis workup events. Results: 141 blood samples were drawn from 36 infants during 85 episodes of sepsis workup performed between 4 and 66 d of life. Of these episodes, 51 (60%) were not a result of documented sepsis and thereby served as the negative comparison group. Median procalcitonin levels were higher in the septic group compared with the non‐septic group at the time of the sepsis workup (2.7 vs 0.5 ng/ml, p=0.003), at 1–24 h after the sepsis workup (4.6 vs 0.6 ng/ml, p=0.003), and at 25–48 h (6.9 vs 2.0 ng/ml, p=0.016). Using high cutoff levels, both procalcitonin (2.3 ng/ml) and CRP (30 mg/l) had high specificity and positive predictive value (97%, 91% and 96%, 87%, respectively) but low sensitivity (48% and 41%, respectively) to detect sepsis. Areas under the ROC curve for procalcitonin and CRP were 0.74 and 0.73, respectively.