Prevalence and clinical significance of heparin induced antibodies in chronic hemodialysis patients and cardiac surgery patients.

INTRODUCTION: The prevalence of heparin-induced antibodies (HIA) varies widely among reported series, but is generally higher in cardiac surgery than hemodialysis patients. This study was designed to explore the reasons behind the different prevalence of HIA in these two populations. METHODS: Blood samples from all hemodialysis and cardiac surgery patients in our hospital were examined for HIA. Heparin-induced thrombocytopenia (HIT) was suspected when platelet count was <150,000 in the hemodialysis group, and >50% decline in platelet count in the cardiac surgery group. RESULTS: 79 hemodialysis and 40 cardiac surgery patients were studied. HIA prevalence was significantly higher in cardiac surgery than in hemodialysis patients (65% v 10.1%, respectively, P<0.00001). Conversely, the prevalence of suspected clinical HIT was 37.5% in the hemodialysis and 11.5% in the cardiac surgery group. Prevalence of HIA was higher in patients who were tested during the first 90 days of hemodialysis than in those tested at later times. One-year mortality was 37% in HIA positive and 19% in HIA negative hemodialysis patients. CONCLUSIONS: Prevalence of HIA was significantly lower in hemodialysis as compared with cardiac surgery patients. Our data suggest that the observed difference in HIA prevalence was either population dependent, or due to different timing of heparin administration in the two groups.

Nursing and physician attire as possible source of nosocomial infections.

BACKGROUND: Uniforms worn by medical and nursing staff are not usually considered important in the transmission of microorganisms. We investigated the rate of potentially pathogenic bacteria present on uniforms worn by hospital staff, as well as the bacterial load of these microorganisms. METHODS: Cultures were obtained from uniforms of nurses and physicians by pressing standard blood agar plates at the abdominal zone, sleeve ends, and pockets. Each participant completed a questionnaire. RESULTS: A total of 238 samples were collected from 135 personnel, including 75 nurses (55%) and 60 physicians (45%). Of these, 79 (58%) claimed to change their uniform every day, and 104 (77%) defined the level of hygiene of their attire as fair to excellent. Potentially pathogenic bacteria were isolated from at least one site of the uniforms of 85 participants (63%) and were isolated from 119 samples (50%); 21 (14%) of the samples from nurses' gowns and 6 (6%) of the samples from physicians' gowns (P = NS) included of antibiotic-resistant bacteria. CONCLUSION: Up to 60% of hospital staff's uniforms are colonized with potentially pathogenic bacteria, including drug-resistant organisms. It remains to be determined whether these bacteria can be transferred to patients and cause clinically relevant infection.

The cellular immunological responses of patients undergoing coronary artery bypass grafting compared with those of patients undergoing valve replacement.

OBJECTIVE: Major surgical intervention such as cardiac surgery has been shown to have profound effects on the immune system. We conducted a prospective study comparing the effects of coronary artery bypass grafting (CABG) versus isolated valve surgery. METHODS: Blood samples were drawn from 59 patients undergoing either elective CABG or elective isolated valve replacement surgery. Samples were obtained preoperatively and on the first and third postoperative days. Total cell counts and differential counts were recorded. Several cellular immunity parameters were determined by flow cytometry. RESULTS: On all postoperative days, significant increases in white blood cell (WBC) and monocyte counts were observed. Significant decreases in all lymphocyte populations were also observed with similar decreases in both helper (CD4) and suppressor (CD8) T cells. An increase in activated T cells was noted on day 1, returning to normal on the third postoperative day. Despite the significant decrease in human leucocyte antigen-DR (HLA-DR) antigen expression on monocytes on both the first and third postoperative days, a significant increase in monocyte activation as represented by increased CD11b and CD64 expression was detected. No significant difference was found for any of the measured parameters between the CABG group and the valve replacement group. Eight patients developed early wound infections, with no correlation with any of the measured parameters, including magnitude and duration of decrease in HLA-DR antigen expression on monocytes. CONCLUSIONS: Cardiac surgery induces both a state of pro-inflammation and of immune suppression. The two major types of cardiac surgery induce similar effects to the immune system. None of the measured parameters was predictive for development of postoperative wound infection.

[Gastrointestinal carriage of Pseudomonas aeruginosa in children residing in chronic care institutes in Jerusalem: high prevalence and high rates of antibiotic resistance].

BACKGROUND: Pseudomonas aeruginosa carriage in the gastrointestinal tract is uncommon in healthy children. Children living in chronic care institutions are often carriers of P. aeruginosa in the respiratory tract, but data is lacking regarding gastrointestinal carriage in these children. AIMS: To examine the carriage rate of P. aeruginosa in children living in chronic care institutions in Jerusalem and to assess resistance rates of the bacteria to different classes of antibiotics. METHODS: Rectal swabs were taken from all children residing in two chronic care institutions in Jerusalem: "St. Vincent" and "Aleh". The swabs were examined for presence of Pseudomonas aeruginosa. The authors used disk diffusion technique and E Test to assess resistance for different antibiotics. RESULTS: Gastrointestinal carriage of P. aeruginosa was detected in 37 out of 125 of the children (30%); 16% of the P. aeruginosa isolates were resistant to carbapenems; 16% were resistant to aminoglycosides, 14% to ureidopenicillins and 11% to quinolones. All isolates were sensitive to ceftazidime and colistin. In 84% of the isolates, the minimal inhibitory concentration (MIC) for meropenem was significantly lower than the MIC for imipenem. SUMMARY: P. aeruginosa is a common colonizer of the gastrointestinal tract of children living in chronic care institutions. Empiric antibiotic treatment against P. aeruginosa should be considered when treating children with acute gastrointestinal pathologies. Antibiotic resistance, and particularly carbapenem resistance, is common in this population. There is a significant difference between the MICs for imipenem and meropenem. Future studies are needed to understand the clinical significance of this finding.

[Vibrio vulnificus infection outside of the fish ponds in northern Israel: acquisition in the "Einot Tzukim" springs near the Dead Sea].

Vibrio vulnificus is a Gram-negative bacterium that may cause severe skin and systemic infection after exposure of open wounds to contaminated water, especially in patients with underlying disease such as immune-deficiency, iron overload or end stage liver or renal disease. The V. vulnificus infection has been reported in Israel almost exclusively after exposure to Tilapia fish cultivated in fresh water fish ponds in northern Israel. The authors report the first case of V. vulnificus infection acquired in a nature reserve in southeastern Israel, with no connection to fish handling. A 14.5-years-old girl with transfusion-dependant thalassemia major presented with high fever and a rapidly progressive bullous cellulitis of the ankle. The infection occurred around a cut on the left lateral malleolus, after bathing in the fresh water ponds of Einot Tzukim (Ein Feshcha) in south-eastern Israel, and progressed despite the use of broad-spectrum antibiotics. Blood and wound cultures eventually yielded Vibrio vulnificus and appropriate treatment was commenced. The fever subsided after a few days but resolution of the local findings was very gradual and lasted for weeks. The presence of V. vulnificus in natural springs far from the northern artificial fish ponds broadens the danger of this infection. We find it prudent to advise people at risk for V. vulnificus infection, such as those suffering from immunedeficiency, iron overload and end stage liver or renal disease, to refrain from bathing in natural ponds whilst injured.

Prospective evaluation of colonization with extended-spectrum beta-lactamase (ESBL)-producing enterobacteriaceae among patients at hospital admission and of subsequent colonization with ESBL-producing enterobacteriaceae among patients during hospitalization.

OBJECTIVE: To determine the rates of and risk factors for carriage and acquisition of extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae during hospitalization. DESIGN: Cohort study. SETTING: Shaare Zedek Medical Center, a 550-bed teaching hospital. METHODS: During a 5-month period (February 1-June 30, 2004), 167 (8%) of 1,985 newly admitted general medical patients were enrolled in our study. Nasal, oropharyngeal, and rectal swab specimens were obtained at admission and every 2-3 days until hospital discharge or death. Enterobacteriaceae isolates were tested for ESBL, and Staphylococcus aureus isolates were tested for methicillin resistance. RESULTS: Of the 167 patients enrolled in our study, 15 (9%) were identified as nasal carriers of methicillin-resistant S. aureus (MRSA) at admission, and 13 (8%) were rectal carriers of ESBL-producing Enterobacteriaceae at admission. Univariate risk factors for rectal carriage of ESBL-producing Enterobacteriaceae included female sex (odds ratio [OR], 11 [95% confidence interval {CI}, 1.4-238]; P < .05), nursing home residence (OR, 6.9 [95% CI, 1.8-27]; P < .01), recent antibiotic treatment (OR, 9.8 [95% CI, 1.7-74]; P < .05), and concomitant nasal carriage of MRSA and/or ESBL-producing Enterobacteriaceae (OR, 5.8 [95% CI, 1.2-26]; P < .01). Multivariate risk factors were female sex and recent antibiotic treatment. During hospitalization, 35 (21%) of 167 patients had acquired rectal carriage of ESBL-producing Enterobacteriaceae (P = .002, for trend analysis). Of the 12 patients who were still in the hospital 2 weeks after admission, 4 (33%) were carriers of ESBL-producing Enterobacteriaceae. Univariate risk factors for acquisition included an age of older than 65 years (P < .005), nursing home residence (OR 2.6, [95% CI, 0.98-2.6]), impaired cognition (OR, 4.8 [95% CI, 1.9-12]), recent antibiotic treatment (OR, 2.7 [95% CI, 0.9-8.3]), respiratory assistance (OR, 4.2 [95% CI, 1.2-14]), and prolonged hospitalization. Multivariate risk factors were an age of older than 65 years and broad-spectrum antibiotic therapy. CONCLUSIONS: Rectal carriage of ESBL-producing Enterobacteriaceae occurred in 13 (8%) of 167 patients at admission to the medical departments of our hospital and in 4 (33%) of 12 patients still remaining in our hospital after 2 weeks.

Cefuroxime for empiric treatment of community-acquired pneumococcal pneumonia: is there a generation gap?

BACKGROUND: Streptococcus pneumoniae infection is an important cause of morbidity and mortality. The recommendations to use expanded-spectrum beta-lactam drugs for patients with community-acquired pneumonia derived from the growing prevalence of penicillin-resistant pneumococci. Controversy exists regarding the use of second generation cephalosporins for empirical treatment of community-acquired pneumonia. METHODS: In a retrospective study, 31 adult patients with pneumococcal pneumonia and bacteremia caused by S. pneumoniae that was intermediately resistant to penicillin were compared with 31 control patients with similar infection caused by penicillin-susceptible pneumococci. All patients were treated empirically with cefuroxime, alone or in combination with other antibiotics. Morbidity and mortality were studied. RESULTS: All unsusceptible pneumococci isolates were intermediately resistant to penicillin. No cases of fully resistant pneumococci were isolated from blood cultures in our hospital. Two factors were significantly associated with non-susceptibility to penicillin: hematologic malignancy and immunosuppression. No significant difference in morbidity or mortality was detected between the 2 groups, and penicillin minimum inhibitory concentration was not found to be a factor associated with mortality. CONCLUSIONS: Patients with pneumococcal pneumonia caused by intermediately resistant pneumococci can be empirically treated with cefuroxime. In regions where fully resistant pneumococci are rare, the use of a second generation cephalosporin for empiric treatment of community-acquired pneumonia may be appropriate.

Failure to predict hemolysis and hyperbilirubinemia by IgG subclass in blood group A or B infants born to group O mothers.

OBJECTIVE: Direct antibody titer-positive, blood group A or B neonates who are born to group O mothers may be at risk for hemolysis and hyperbilirubinemia. Immunoglobulin G1 and immunoglobulin G3 subclasses are associated with increased hemolysis relative to immunoglobulin G2 and immunoglobulin G4. We investigated whether identification of immunoglobulin G subclass 1 or 3 may be predictive of hemolysis and hyperbilirubinemia. METHODS: Direct antibody titer-positive, blood group A and B neonates born to group O mothers were tested for the presence of immunoglobulin G subclasses 1 and 3 in umbilical cord blood by using a commercially available gel testing technology. By inference, neonates in whom neither immunoglobulin G1 nor immunoglobulin G3 were detected were designated immunoglobulin G2 and/or 4. Mandatory plasma total bilirubin was measured at discharge, and additional measurements performed as clinically indicated. Hyperbilirubinemia was defined as any plasma total bilirubin value >95th percentile for hour of life. Blood carboxyhemoglobin and total hemoglobin concentrations were also measured on the predischarge sample. Measured carboxyhemoglobin, expressed as percentage of total hemoglobin, was corrected for ambient carbon monoxide to derive "corrected carboxyhemoglobin," a sensitive index of heme catabolism. The corrected carboxyhemoglobin/total hemoglobin ratio was calculated to correct for any differences in total hemoglobin mass between groups. RESULTS: Eighty-two infants were studied, 18 of whom were designated as immunoglobulin G1, 0 as immunoglobulin G3, and 64 as immunoglobulin G2 and/or 4. The incidence of plasma total bilirubin >95th percentile was similar between the subgroupings. Corrected carboxyhemoglobin values and corrected carboxyhemoglobin/total hemoglobin ratio were also similar between the subgroupings. CONCLUSIONS: Immunoglobulin G1 was found in 22% of direct antibody titer-positive, group A and B neonates who were born to group O mothers, whereas immunoglobulin G3 was rare. Hemolysis and hyperbilirubinemia could not be predicted by this gel technique that enabled identification of these immunoglobulin G subclasses.

Neutrophil CD64 expression as a diagnostic marker of bacterial infection in febrile children presenting to a hospital emergency department.

BACKGROUND: The expression of CD64 (Fcgamma receptor) is increased in neutrophils from an almost negligible value to a marked level in patients with bacterial infections. CD64 expression on neutrophils might therefore be useful to differentiate between bacterial and viral infections in young children. We evaluated the usefulness of CD64 as a marker for the diagnosis of bacterial infections in children up to the age of 3 years and its ability to differentiate between bacterial and viral infections. METHODS: Blood samples were drawn from 70 children aged 3 years or younger who presented to the pediatric emergency department with fever as their main complaint. Thirty-eight children were diagnosed as having bacterial infection and 32 as having viral infection. The control group included 39 healthy children. CD64, C-reactive protein (CRP), and procalcitonin levels were determined for each child. The sensitivity and specificity of these parameters were calculated. RESULTS: Neutrophil expression of CD64 was significantly higher in the bacterial infection group compared with the viral infection and the control groups (P < 0.0001). Raising the cutoff for diagnosis of bacterial disease lowered the sensitivity but improved the specificity. CD64 was found to have a very high sensitivity (94.7%), but its specificity was poor (46.5%). No significant differences were found between the diagnostic performance of CD64 and that of CRP: both have high sensitivity and low specificity (94.7% and 47.9%, respectively, for CRP). In contrast, procalcitonin had a betterspecificity (91%), but its sensitivity reached only 71.9%. CD64 expression was increased in patients with respiratory syncytial virus-related infections compared with that in patients with other viral infections and was similar to that found during bacterial illness. CONCLUSIONS: Neutrophil CD64 expression is a sensitive marker for diagnosing bacterial infection in young children, but as it is also raised in viral infection, it lacks specificity.

Incidence and significance of a positive troponin test in bacteremic patients without acute coronary syndrome.

BACKGROUND: Since the introduction of troponin for the diagnosis of myocardial infarction, several studies have shown additional conditions in which troponin is elevated, including sepsis. The objective of this study was to determine the incidence of an elevated troponin in patients with bacteremia and its significance. METHODS: This was a prospective, noninterventional study. Patients with a positive blood culture were included. Cardiac troponin I (cTnI) was determined within 4 days of blood culture. A repeat electrocardiogram was obtained in a sample of patients with elevated cTnI and in patients with a negative troponin test. Demographic, clinical, and microbiological data were obtained for all patients. RESULTS: A total of 159 bacteremic patients were included. Positive cTnI was detected in 69 patients (43%). Elevated cTnI was associated with a number of underlying diseases, hospitalization ward, severity of the systemic inflammatory condition, and kidney function (P<.05-.001). A repeat electrocardiogram was performed in 39 patients with a positive cTnI and in 28 patients with a negative cTnI. Two of 39 patients (5%) in the positive cTnI group had ischemic changes and 2 patients (5%) had nonspecific changes, whereas only 1 patient (4%) with a negative cTnI had nonspecific changes. Bivariate analysis revealed a statistically significant association for positive cTnI and mortality; however, on multivariate analysis this was no longer significant. CONCLUSION: Forty-three percent of bacteremic patients had an elevated cTnI. Risk factors for elevated cTnI were severity of the underlying infection, renal function, and underlying cardiac disease. Increased cTnI was found to be a dependent risk factor and a surrogate marker for death.

Direct fluconazole susceptibility testing of positive Candida blood cultures by flow cytometry.

The standard methods for yeast susceptibility testing require 24-48 h of incubation. As there has been an increase in incidence of non-albicans Candida species, the clinician is very often wary of initiating therapy with fluconazole until a final susceptibility report is generated, especially when treating very sick patients. A rapid reliable susceptibility testing method would enable the clinician to prescribe fluconazole, thus avoiding more toxic or expensive therapy. To determine the feasibility of direct susceptibility testing of Candida species to fluconazole by a rapid flow cytometric method, 50 Candida strains were seeded into blood culture bottles and were tested for susceptibility to fluconazole directly from the bottles after their being flagged as positive by the blood culture instrument. Minimal inhibitory concentration (MIC) determined by fluorescent flow cytometry (FACS) showed excellent agreement to that determined by macrodilution. Following the seeding experiments, 30 true patient specimens were tested directly from positive blood cultures, and MIC determined by both methods showed excellent agreement. Antifungal susceptibility testing by FACS directly from positive blood culture bottles is a reliable, rapid method for susceptibility testing of Candida to fluconazole. The method allows same-day results, does not require subculture to agar media, and can greatly assist in the selection of appropriate antifungal therapy.

Enoxaparin dosage adjustment in patients with severe renal failure: antifactor xa concentrations and safety.

STUDY OBJECTIVE: To evaluate the safety and efficacy, by measuring antifactor Xa levels, of enoxaparin 1 mg/kg subcutaneously once every 24 hours in patients with severe renal failure. DESIGN: Prospective study. SETTING: Emergency, internal medicine, geriatrics, and cardiology departments of a medical center in Israel. PATIENTS: Nineteen patients with stage 4 or 5 chronic kidney disease who required full anticoagulation. INTERVENTION: Patients received enoxaparin 1 mg/kg subcutaneously every 24 hours for 2 or more days, as determined by a treating physician. MEASUREMENTS AND MAIN RESULTS: Data on patients' demographic and clinical characteristics were collected. Blood samples for peak and trough antifactor Xa levels were obtained during the enoxaparin treatment period. Of the 19 study patients, 14 (74%) had peak antifactor Xa levels within the recommended range for full anticoagulation of 0.5-1.0 U/ml after their first enoxaparin dose; no concentration exceeded 1.0 U/ml. The mean peak antifactor Xa level was not significantly different after the first enoxaparin dose compared with the second and third doses. The mean +/- SD trough antifactor Xa level, thought to be an indicator of drug accumulation, was 0.12 +/- 0.12 U/ml; its clinical significance and target range are still unknown. No major bleeding events were noted. CONCLUSION: Enoxaparin 1 mg/kg once every 24 hours in patients with stage 4 or 5 chronic kidney disease who required full anticoagulation was safe, and this dose did not exceed recommended concentrations. The significance of enoxaparin trough levels remains unclear and should be investigated in future studies. Other dosing regimens of enoxaparin for specific patient populations should also be assessed for safety and efficacy.

Monitoring of Gaucher patients with a novel chitotriosidase assay.

BACKGROUND: Chitotriosidase (CT) is a surrogate plasma marker for Gaucher disease. The enzyme is released by storage cells and is on average thousand fold elevated in serum of Gaucher patients. Plasma CT level is measured with the substrate 4-methylumbelliferyl (4MU)-chitotriose or 4MU-chitobiose. Given the limitations associated with the use of these substrates, a novel substrate, 4MU-deoxychitobiose, has recently been conceived. METHODS: Chitotriosidase activity was measured with all three substrates in serum samples from 91 type 1 Gaucher patients. Glucocerebrosidase and chitotriosidase genotypes were determined as well as disease parameters. RESULTS: Chitotriosidase activity when measured with 4MU-deoxychitobiose gave higher values and was proportional to enzyme concentration over a much larger range as compared to the other two substrates. Patients that were carrier for the common CT mutation showed on average half the activity of those with wild type CT genotype. Plasma CT levels correlated best with combined liver and spleen volume: r=0.53 (p<0.001). CONCLUSIONS: The use of 4MU-deoxychitobiose as substrate renders a substantial improved CT activity assay and may further facilitate accurate laboratory monitoring of Gaucher patients.

Susceptibilities of ESBL-producing Enterobacteriaceae to ertapenem, meropenem and piperacillin-tazobactam with and without clavulanic acid.

BACKGROUND: Faced with the extended-spectrum beta-lactamase (ESBL) pandemic, we compared the susceptibilities of ESBL-producing Enterobacteriaceae to ertapenem, meropenem and piperacillin-tazobactam with and without clavulanate. METHODS: 121 strains of Escherichia coli and Klebsiella were studied. 70 strains were originally reported as resistant to ceftazidime based upon disk diffusion; 51 strains were originally reported as sensitive to ceftazidime based upon previous guidelines of the National Committee for Clinical Laboratory Standards, but subsequently shown to be ESBL producers. Minimal inhibitory concentrations (MICs) of the strains towards ertapenem, meropenem and piperacillin-tazobactam were determined by Etest. The effect of adding clavulanate on the MICs was determined by performing the Etest, using plates containing 2 microg/ml of clavulanate. RESULTS: The MIC90 of all isolates was 0.094 and 0.25 microg/ml for ertapenem, 0.032 and 0.064 microg/ml for meropenem, and 16 and 256 microg/ml for piperacillin-tazobactam with and without clavulanate, respectively. CONCLUSIONS: ESBL-producing organisms were more susceptible to meropenem than to ertapenem, although the MICs to ertapenem were well within clinically achievable levels. Piperacillin-tazobactam was ineffective in a large percentage of isolates. The presence of clavulanate resulted in a 5-fold decrease in the MIC of ertapenem and in a drastic reduction in the MIC of piperacillin-tazobactam. The decrease observed with ertapenem is unlikely to be of clinical significance. Thus, in our hospital, ertapenem could be a good meropenem-sparing agent for infections due to ESBL-producing organisms. Piperacillin-tazobactam appeared to be a poor choice, as our isolates produce ESBLs which are not successfully inhibited by tazobactam.

Low levels of procalcitonin during episodes of necrotizing enterocolitis.

The pathogenesis of necrotizing enterocolitis (NEC) remains poorly understood. We aimed to assess the extent of bacterial infection in the pathogenesis of NEC using serial procalcitonin measurements. Blood samples were drawn during the first 4 days following every clinical event requiring a workup for presumed NEC. Eight episodes were confirmed as NEC, 7 of which showed procalcitonin levels <1 ng/ml at presentation and <1.3 ng/ml thereafter, comparable to 24 healthy controls. The one infant with elevated procalcitonin had bacteremia in addition to NEC. Procalcitonin levels of 24 matched septic infants were higher than those of NEC infants, peaking at 4.1 ng/ml. We conclude that low procalcitonin values are the rule during episodes of NEC and provide further evidence that overactive local immune response, and not active infection, is primarily responsible for the mucosal damage in NEC.

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

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. CONCLUSION: Procalcitonin >2.3 ng/ml or CRP >30 mg/l indicates a high likelihood for neonatal sepsis, and antibiotic therapy should be continued even in the presence of sterile cultures.

Prevention of early-onset neonatal group B streptococcal infection: is universal screening by culture universally applicable?

BACKGROUND: Previous assessments of maternal group B Streptococcus carrier rates in women delivering at Shaare Zedek Medical Center ranged between 3.5 and 11% with neonatal sepsis rates of 0.2-0.9/1000 live births. Because of low colonization and disease rates, routine prenatal cultures of GBS were not recommended and intrapartum prophylaxis was mainly based on maternal risk factors. OBJECTIVES: To determine whether this policy is still applicable. METHODS: We performed prospective sampling and follow-up of women admitted for labor and delivery between February 2002 and July 2002. Vaginal and rectal cultures were obtained before the first pelvic examination. GBS isolation was performed using selective broth medium and identified by latex agglutination and serotyping. Demographic data were collected by means of a standardized questionnaire. Data on the newborns were collected throughout 2002. RESULTS: Of the 629 sampled women, 86 had a positive culture and a carrier rate of 13.7%. A borderline significantly higher carriage rate was observed among mothers of North American origin (21% vs. 13.1%, P= 0.048), and a higher attack rate in their infants (3.8/1000 compared with 0.5/1000 live births in our general maternal population, P= 0.002). Eight newborns had early-onset neonatal GBS sepsis (a rate of 0.8/1000 live births), but none of them benefited from intrapartum antibiotic prophylaxis. CONCLUSIONS: An increased neonatal disease rate was observed in a population with a higher colonization rate than previously seen. In view of the higher carrier rates, we now recommend routine prenatal screening for GBS in our perinatal population.

The role of enzyme-linked immunosorbent assay D-dimer in patients with acute coronary syndrome presenting with normal cardiac enzymes.

Plasma D-dimer levels, the primary degradation product of cross-linked fibrin, are elevated in acute coronary syndrome (ACS). However, the role of D-dimer in patients presenting to the Emergency Department with ACS and normal cardiac enzymes is unknown. We conducted a prospective, observational study in the Emergency Department of a major tertiary university-affiliated center. The study included 124 patients presented to the Emergency Department with ACS and normal cardiac enzymes. Blood samples were collected and assayed for D-dimer levels with the enzyme-linked immunosorbent assay (ELISA) test. The D-dimer values were correlated with the clinical, laboratory and electrocardiographic findings on admission, as well as with the catheterization findings and with hospital length of stay. ELISA D-dimer levels positively correlated with sex, hypertension and smoking (r = -0.27, P = 0.002; r = 0.33, P = 0.0002; and r = -0.24, P = 0.007, respectively). Significant correlation was also observed between ELISA D-dimer and cardiac medications including beta-blocker (r = 0.22, P = 0.01), aspirin (r = 0.18, P = 0.04), nitrate (r = 0.20, P = 0.002), acute phase reactants fibrinogen (r = 0.45, P = 0.0001) and C-reactive protein (r = 0.29, P = 0.004), ischemic electrocardiographic changes (r = 0.21, P = 0.02) and length of stay (r = 0.29, P = 0.001). The catheterization findings were also correlated with the ELISA D-dimer levels (r = 0.31, P = 0.02). The ELISA D-dimer test may add important clinical data concerning patients with ACS and normal cardiac enzymes.

Risk factors for Clostridium difficile toxin-positive nosocomial diarrhoea.

Data were retrieved from the records of all patients from whom stool was sent for Clostridium difficile toxin testing during the year 2001. Toxin-positive and -negative patients were compared by bivariate analysis and regression models. Eight hundred samples from 610 patients were sent for C. difficile toxin testing. Charts of 535 patients (88%) were available for analysis. Of those, 17% had a positive toxin test whilst 83% had a negative toxin test. There was no difference in the number of daily bowel movements between the two groups. Toxin-positive patients were older (P<0.0001), more often came from nursing homes (P<0.05), had higher leukocyte counts (P<0.001), higher blood urea nitrogen (P<0.01), lower serum albumin (P<0.01) and more often received diuretics (P<0.01) and clindamycin (P<0.05). Logistic regression analysis showed that previous antibiotic-associated diarrhoea was the most significant risk factor for toxin-positive diarrhoea (P<0.001), followed by clindamycin treatment (P<0.005), diuretics (P<0.005) and older age (P<0.05). Another logistic model showed the contribution of macrolides (P<0.05) to the development of hospital-acquired diarrhoea.

Acquisition of multidrug-resistant organisms among hospital patients hospitalized in beds adjacent to critically ill patients.

OBJECTIVE: To assess whether patients hospitalized in beds physically adjacent to critically ill patients are at increased risk to acquire multidrug-resistant pathogens. DESIGN: Cohort study.Setting. Shaare Zedek Medical Center, a 550-bed medical referral center. PATIENTS: From April to September 2004, we enrolled consecutive newly admitted patients who were hospitalized in beds adjacent to either mechanically ventilated patients or patients designated as "do not resuscitate" (DNR). For each of these patients, we also enrolled a control patient who was not hospitalized in a bed adjacent to a critically ill patient. We collected specimens from the anterior nares, the oral cavity, and the perianal zone at the time of admission and subsequently at 3-day intervals until discharge or death. Specimens were cultured on selective media to detect growth of antibiotic-resistant pathogens, including Acinetobacter baumannii, methicillin-resistant Staphylococcus aureus (MRSA), extended-spectrum beta lactamase (ESBL)-producing Enterobacteriaceae, and vancomycin-resistant enterococci (VRE). RESULTS: We enrolled 46 neighbor-control pairs. Among neighbors and controls, respectively, the incidence rates for isolation of A. baumannii was 8.3 and 4 isolations per 100 patient-days (relative risk [RR], 2.1 [95% confidence interval {CI}, 0.8-5.2]; P=.12), the incidence rates for MRSA were 1.4 and 2.6 isolations per 100 patient-days (RR, 0.6 [95% CI, 0.1-2.3]; P=.45), the incidence rates for ESBL-producing Enterobacteriaceae were 10.5 and 9 isolations per 100 patient-days (RR, 1.2 [95% CI, 0.6-2.4]; P=.84), the incidence rates for VRE were 4.3 and 4.8 isolations per 100 patient-days (RR, 0.9 [95% CI, 0.3-2.4]; P=1), and the composite incidence rate was 21.7 and 16.2 isolations per 100 patient-days (RR, 1.3 [95% CI, 0.8-2.3]; P=0.3). CONCLUSIONS: In this pilot study, we did not detect an increased incidence rate of isolation of multidrug-resistant pathogens among patients hospitalized in beds adjacent to critically ill patients. Further studies with larger samples should be conducted in order to generate valid data and provide patients, physicians, and policy makers with a sufficient knowledge base from which decisions can be made.