David Raveh

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

Angioplasty with stent graft versus bare stent for recurrent cephalic arch stenosis in autogenous arteriovenous access for hemodialysis: A prospective randomized clinical trial

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.

Bacteremia due to beta-hemolytic streptococcus group g: increasing incidence and clinical characteristics of patients

BACKGROUND Early recurrent stenosis of the cephalic arch in autogenous arteriovenous access for hemodialysis is a common problem that requires stenting to prevent thrombosis. Because the results of stenting are unsatisfactory, we compared the efficacy of stent grafts with bare stents in these patients. METHODS All patients who presented with recurrent cephalic arch stenosis >50% within 3 months of successful balloon angioplasty were randomized to have angioplasty and stenting with either a bare nitinol stent or a stent graft. Outcome was assessed by angiography 3 months later. Restenosis was defined as >50% narrowing of the stent lumen or of the vessel margin up to 0.5 cm adjacent to the stent. There were no exclusions. RESULTS This report includes data on the outcome of 25 consecutive patients with recurrent cephalic arch stenosis who were treated from April to August 2006. At 3 months, three patients had died and one had undergone a renal transplant. The 21 patients who had angiography at 3 months had patent stents. Restenosis rates were seven of 10 (70%) in the bare stent group and two of 11 (18%) in the stent graft group (P = .024). Life-table analysis at 3 and 6 months showed that primary patency was 82% in the stent graft group and 39% in the bare stent group. One-year primary patency was 32% in the stent graft group and 0% in the bare stent group (P = .0023). During a mean follow-up of 13.7 months, nine patients died, four in the bare stent group and five in the stent graft group. Two patients in the stent graft group had received a renal transplant. The number of interventions per patient-year was 1.9 in the bare stent group and 0.9 in the stent graft group (P = .02). CONCLUSIONS The use of stent grafts in angioplasty for recurrent cephalic arch stenosis significantly improved short-term restenosis rates and long-term patency compared with the use of bare stents. The significant improvement that emerged during the study caused accrual of patients to be halted for ethical reasons. This study altered our usage of stents for venous stenoses in arteriovenous accesses by eliminating bare nitinol stents in favor of stent grafts.

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

PURPOSE To describe the epidemiology and clinical characteristics of patients diagnosed with Streptococcus group G bacteremia from 1990 to 1999 at a community teaching hospital in Israel. SUBJECTS AND METHODS We calculated the annual rate of bacteremia with Streptococcus group G, expressed as a percentage of positive blood cultures (after excluding contaminants) and per 1000 admissions. Medical records of patients with Streptococcus group G were reviewed. RESULTS During the 10-year study period, there was a total of 7415 positive blood cultures, 327 (4.4%) of which were beta-hemolytic Streptococcus species, of which 49 (15%) were group G. The rate of Streptococcus group G bacteremia per 1000 admissions increased from zero (0/18,783) in 1990 to 0.41 (13/31,440) in 1999 (P = 0.001), surpassing Streptococcus group A in frequency. Of the 47 patients with Streptococcus group G, 40 medical records were available for review: 25 patients (63%) were older than 75 years and 32 (80%) were men. The probable source of Streptococcus group G bacteremia was a skin or soft tissue infection in 37 patients (93%). Six of the 40 patients died. CONCLUSION Community-acquired group G streptococcal bacteremia occurred with increasing frequency from 1990 to 1999 at our hospital. Most patients were elderly men, and the portal of entry was usually the skin or soft tissue. Our findings suggest a change in the epidemiology of bacteremia due to beta-hemolytic streptococci.

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

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.

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

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.

Age as a Risk Factor for Severe Plasmodium falciparum Malaria in Nonimmune 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

In this nationwide, cross-sectional study, we evaluated the influence of age and other factors that affect clinical outcome of Plasmodium falciparum malaria in nonimmune patients. Of 135 patients with P. falciparum malaria, 84 (62%) were < 40 years old, and only 5% of the patients in this age group developed severe malaria, compared with 18% of the subjects who were > or =40 years of age (odds ratio, 4.29); moreover, all deaths occurred in the latter group. Male subjects did not differ from female subjects with regard to severity of disease.

A Large Q Fever Outbreak in an Urban School in Central Israel

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.

Tumor necrosis factor-α blocking agent as a treatment for nephrotic syndrome

BACKGROUND. On 28 June 2005, numerous cases of febrile illness were reported among 322 students and employees of a boarding high school located in an urban area in central Israel. Subsequent investigation identified a large outbreak of Q fever which started 2 weeks earlier. We describe the investigation of this outbreak and its possible implications. METHODS. We conducted a case-control study to identify risk factors for Q fever disease. Environmental sampling was conducted to identify the source and the mode of transmission of Coxiella burnetii, the infectious agent. RESULTS. Of 303 individuals, 187 (62%) reported being ill between 15 June and 13 July 2005. Serological evidence for C. burnetii infection was evident in 144 (88%) of the 164 tested individuals. Being a student, dining regularly at the school dining room, and boarding at school during a June religious holiday and the preceding weekend were all significant risk factors for contracting Q fever. C. burnetii DNA was detected using polymerase chain reaction on samples from the school dining rooms air conditioning system, supporting contribution of the air conditioning system to the aerosol transmission of the infectious agent. CONCLUSIONS. We report a large outbreak of Q fever in an urban school, possibly transmitted through an air conditioning system. A high level of suspicion for C. burnetii infection should be maintained when investigating point source outbreaks of influenza-like disease, especially outside the influenza season.