A simplified blood culture sampling protocol for reducing contamination and costs: a randomized controlled trial

OBJECTIVES

Blood culture contamination carries risks for patients, such as unnecessary antimicrobial therapy and other additional hazards and costs. One method shown to be effective in reducing contamination is initial blood specimen diversion during collection. We hypothesized that initial blood specimen diversion without a designated device or procedure would suffice for reduction in blood culture contamination rate.

METHODS

From 1 September 2017 through to 6 September 2018, we conducted a randomized controlled trial to assess the effect of an initial-specimen diversion technique (ISDT) on the rate of blood-culture contamination by changing the order of sampling using regular vacuum specimen tubes instead of commercially available sterile diversion devices. We included adults from whom the treating physician planned to take blood cultures and additional blood chemistry tests. Additionally, we evaluated the potential economic benefits of an ISDT. This was a researcher-initiated trial, Clinicaltrials.gov NCT03088865.

RESULTS

In all, 756 patients were enrolled. This method, compared with the standard procedure in use at our medical centre, reduced contamination by 66% (95% CI 17%-86%), from 20/400 (5%) with the standard method to 6/356 (1.6%) with the ISDT, without compromising detection of true bloodstream infection and at no additional cost. Hospital-wide implementation of ISDT was associated with a 1.1% saving in hospitalization days.

CONCLUSIONS

We offer this novel approach as a simple, cost-effective measure to reduce risks to patient safety from contaminated blood cultures, without the need for using costly devices.

Invasive meningococcal disease epidemiology and characterization of Neisseria meningitidis serogroups, sequence types, and clones; implication for use of meningococcal vaccines

BACKGROUND AND AIMS

Neisseria meningitidis (N. meningitidis) is a Gram-negative bacterium that can cause life-threatening invasive infections referred to as invasive meningococcal disease (IMD). In the last decade the incidence of IMD in Israel is about 1/100,000 population annually. We aimed to describe the epidemiology of IMD in Israel combining epidemiological data and characterization of N. meningitidis isolates.

METHODS

Invasive infection caused by N. meningitidis is a notifiable disease in Israel. Data were collected by epidemiological investigations and control measures were employed. Laboratory work-up included serogrouping, N. meningitides molecular characterization and whole-genome sequencing.

RESULTS

During 1998-2017, 1349 cases of IMD were notified in Israel (mean annual incidence rate 0.94/100,000). The peak incidence rates were observed in infants under 1 year of age (10.9/100,000). Case fatality rate was 9.7%. The majority of the N. meningitidis isolates were of serogroup B (67.9%). During 2007-2017, three clonal complexes (CC) 32, 41/44 and 23 (hyper-invasive clonal complexes) were the leading CC (61%). CC32 was the leading CC causing meningococcemia and mortality. In 2017, 35 isolates were tested for 4CMenB antigens variants; of the serogroup B isolates tested 46.7% showed a match to one or more antigens (fHbp or PorA:VR1), most were ST32 (CC32).

CONCLUSIONS

Preliminary analysis based on limited number of samples suggests that the 4CMenB coverage would be about half the strains; further research is necessary. Integration of clinical, epidemiological and laboratory data is essential to support decision-making on the introduction of the novel MENB vaccines in Israel.

Seasonality of tuberculosis in Israel, 2001-2011

BACKGROUND

Several studies have suggested that the incidence of tuberculosis (TB) varies with the seasons.

OBJECTIVE

To determine the seasonality of TB in Israel and to explore possible associations with climatic variables.

METHODS

Laboratory-confirmed TB cases reported between 2001 and 2011 in individuals resident in Israel for at least 1 year before diagnosis were included in the study. Climatic variables included average temperature and average ultraviolet radiation. The mean serum 25-hydroxyvitamin D level of the population was also recorded.

RESULTS

Of all 2653 TB cases, incidence peaked during spring (n = 712) and reached its nadir during the fall (n = 577), with a case proportion amplitude (CPA) of 5.1% (P = 0.036). Individuals born in the Horn of Africa exhibited a CPA of 9.5% (P = 0.077). Mean population 25-hydroxyvitamin D level was significantly correlated with the seasonal pattern of the disease. Southern Israel had the highest global radiation and, counter-instinctively, the highest TB incidence.

CONCLUSIONS

TB exhibited a seasonal tendency in Israel, with the spring peak/fall nadir pattern found elsewhere. Vitamin D is suspected to be an explanatory variable for this seasonal phenomenon. The finding that the highest incidence is in the area receiving the highest global radiation suggests population-related vulnerability to vitamin D deficiency.

Preoperative Hand Decontamination in Ophthalmic Surgery: A Comparison of the Removal of Bacteria from Surgeons' Hands by Routine Antimicrobial Scrub versus an Alcoholic Hand Rub

PURPOSE

The goal of this experiment was to evaluate and compare the antimicrobial efficacy of routine preoperative hand washing using commercial medicated sponge brushes versus an alcoholic hand rub, by comparing bacterial growth on ophthalmic surgeons' hands after application of each of these methods.

METHODS

Twenty ophthalmic surgeons were recruited at the Hadassah-Hebrew University Medical Center in Jerusalem, Israel. Samples were collected twice from the hands of each surgeon after hand decontamination using two different protocols during routine surgical practice. The routine preparation consisted of a 3-minute surgical scrub using commercial brush-sponges incorporating either 4% chlorhexidine gluconate (CHG) or 1% povidone-iodine (PVP-I) formulations with detergent, followed by drying the hands with a sterile towel, while the 70% ethanol solution was applied for 60-seconds and allowed to air dry. Half of the group was randomly assigned to provide samples first after the routine method and the alcoholic solution a week later, and the other half of the group was sampled in the reverse order. Viable counts of bacteria were evaluated using a modified glove juice method. Bacterial colonies were enumerated after incubation for 24 hours and expressed as colony forming units (CFU)/mL for each pair of hands.

RESULTS

Geometric mean counts were 1310 and 39 CFU/mL, in the routine and alcohol rub groups, respectively, representing a mean log₁₀ reduction in 1.53. The difference between the paired bacterial counts for the routine versus the alcohol rub was statistically significant (p < 0.0001). There was no statistically significant difference between log₁₀ reductions for CHG and PVP-I (p = 0.97).

CONCLUSIONS

This study provides evidence that an alcohol rub protocol is more effective in reducing bacterial counts on hands than routine surgical hand preparation with PVP-I and CHG in a population of practicing ophthalmic surgeons in the operative clinical setting. Thus, it provides a safe alternative as a preoperative hand disinfection method.

Invasive Aspergillosis in Neutropenic Patients with Hematological Disorders

Between 1983-1988, 72 patients with acute leukemia and 4 with aplastic anemia were treated in the Hematology Unit of The Chaim Sheba Medical Center. Ten patients with acute leukemia developed invasive pulmonary aspergillosis and 2 with aplastic anemia developed invasive aspergillosis of the nose and paranasal sinuses. These infections were diagnosed during a period of profound neutropenia while these patients were receiving broad spectrum antibiotics. The diagnosis of pulmonary aspergillosis was based on positive sputum cultures in 4 cases and on the appearance of typical clinical and radiologic features in six. In 2 culture-positive and in one culture-negative patient, the diagnosis was confirmed at autopsy. Thus, the diagnosis was definitive in 5 patients and probable in the remaining five patients. The 5 patients who achieved remission responded to antifungal treatment and recovered, while of the 5 who eventually died from the fungal infection, 4 did not achieve remission, and one died while in complete remission. In the 2 patients with aplastic anemia, aspergillosis was detected in cultures from necrotic nasal tissue. Both patients remained neutropenic, failed to respond to antifungal treatment and died within a short time after diagnosis. From this experience it appears that invasive aspergillosis in neutropenic patients is potentially curable if treated early by amphotericin B, provided that the neutrophil count recovers.

Cost-utility analysis of a nationwide vaccination programme against serogroup B meningococcal disease in Israel

OBJECTIVES

Using cost-utility analysis, to evaluate whether or not to adopt a Neisseria meningitidis serogroup B vaccination programme for Israeli children.

METHODS

Epidemiological, demographic, health service utilisation and economic data were integrated into a spreadsheet model to calculate the cost per averted disability-adjusted life year (DALY) of the intervention.

RESULTS

Assuming 78 % vaccine efficacy with no herd immunity, vaccination will prevent 223 cases and 22 deaths over a 100-year period. Based on vaccine price of $60 per dose, total intervention costs ($315,400,000) are partially offset by a $22,700,000 reduction in treatment and sequelae costs as a result of decreased morbidity. The intervention was not cost-effective since the net cost ($292,700,000) per averted DALY gained (1249 mostly due to decreased mortality) was $234,394. Additional two dose catch-up programmes vaccinating children in cohorts aged 1-2 to 1-13 were also not cost-effective.

CONCLUSIONS

The vaccination will become cost-effective if vaccine costs fall below $19.44 per dose. However, in identified high risk areas, the vaccine would be cost-effective and could be recommended for use both with and without catch-up campaigns.

Reduction in incidence of invasive fungal infection in patients receiving allogeneic stem cell transplantation using combined diagnostic-driven approach and itraconazole oral solution

Invasive fungal infections are an important cause of morbidity and mortality after allogeneic haematopoietic stem cell transplantation. We evaluated, in our allogeneic stem cell transplant patients, the effect on the incidence of invasive fungal infection during neutropenia of a strategy combining a diagnostic-driven approach with chemoprophylaxis during higher risk periods of graft vs. host disease and prolonged neutropenia, using itraconazole oral solution with parenteral voriconazole bridging. One hundred and thirty patients admitted for allogeneic stem cell transplantation within two predefined 20 month periods were included in the study. Data for all patients were collected prospectively. Implementation of the protocol resulted in the administration of more prophylactic antifungals to more patients. Following implementation, there was a non-significant decrease in the overall number of invasive fungal infections (IFI) [11 of 65 patients (17.2%) vs. 4 of 65 patients (6.2%, P = 0.051)], as well as in the occurrence of invasive mould infections [8 of 65 patients (12.5%) vs. 2 of 65 patients (3.1%, P = 0.054)]. Survival rates at three and 6 months were not significantly affected. A combined diagnostic-driven approach and antifungal prophylaxis with oral itraconazole and an intravenous voriconazole bridging protocol, was associated with a reduced, albeit non-statistically significant, number of IFI in our medical centre.

A national survey of the molecular epidemiology of Clostridium difficile in Israel: the dissemination of the ribotype 027 strain with reduced susceptibility to vancomycin and metronidazole

Our goals were to study the molecular epidemiology and antimicrobial susceptibilities of C. difficile strains in Israel. Microbiology laboratories serving 6 general hospitals (GH) and 10 long-term care facilities (LTCF) were asked to submit all stool samples in January-February 2014 that tested positive for C. difficile. Toxigenic C. difficile isolates were recovered in 208 out of 217 samples (95.8%), of which 50 (23.6%) were from LTCFs. Ribotype 027 was the most common type overall, identified in 65 samples (31.8%), and was the predominant strain in the 3 GHs with the highest incidence of C. difficile infections. Other common strains were slpA types cr-02 (n = 45) and hr-02 (n = 18). The proportions of vancomycin and metronidazole MIC values >2mg/L were high in ribotype 027 (87.7% and 44.6%, respectively) and slpA-cr-02 strains (88.8% and 17.8%, respectively). This study demonstrates that the ribotype 027 strain has disseminated across Israel and is now the most common strain.

Institutional Control Measures to Curtail the Epidemic Spread of Carbapenem-Resistant Klebsiella pneumoniae: A 4-Year Perspective

Objective.

To describe the implementation of an institution-wide, multiple-step intervention to curtail the epidemic spread of carbapenem-resistant Klebsiella pneumoniae (CRKP).

Design.

Consecutive intervention analyses.

Patients and Setting.

All patients admitted to a 775-bed tertiary care medical center in Jerusalem, Israel, from 2006 through 2010.

Interventions.

The effects of 4 interventions were assessed: (1) a policy of isolation for patients colonized or infected with CRKP in single rooms, which was started in March 2006; (2) cohorting of CRKP patients with dedicated nursing staff and screening of patients neighboring a patient newly identified as a carrier of CRKP, which was started in March 2007; (3) weekly active surveillance of intensive care unit patients, which was started during August 2008; and (4) selective surveillance of patients admitted to the emergency department, which was started in March 2009. Interrupted regression analysis and change-point analysis were used to assess the effect of each intervention on the CRKP epidemic.

Results.

Patient isolation alone failed to control the spread of CRKP, with incidence increasing to a peak of 30 new cases per 1,000 hospital beds per month. Institution of patient cohorting led to a steep decline in the incidence of CRKP acquisition (P< .001). Introduction of active surveillance interventions was followed by a decrease in the incidence of CRKP-positive clinical cultures but an increase in the incidence of CRKP-positive screening cultures. The mean prevalence of CRKP positivity for the period after cohorting began showed a statistically significant change from the mean prevalence in the preceding period (P< .001).

Conclusions.

The cohorting of patients with dedicated staff, combined with implementation of focused active surveillance, effectively terminated the epidemic spread of CRKP. Cohorting reduced cross-infection within the hospital, and active surveillance allowed for earlier detection of carrier status. Both interventions should be considered in attempts to contain a hospital epidemic.

Cluster of Pseudoinfections withBurkholderia cepaciaAssociated with a Contaminated Washer-Disinfector in a Bronchoscopy Unit

In December 2008, bronchoalveolar lavage fluid samples obtained from 3 patients were positive forBurkholderia cepaciacomplex on culture. Samples obtained from bronchoscopes and rinse-water samples obtained from the washer-disinfector were found to be positive forB. cepaciacomplex. The cause of this pseudo-outbreak was that the washer-disinfector was installed without the required antibacterial filter.

Pregnancy-associated listeriosis: clinical characteristics and geospatial analysis of a 10-year period in Israel

BACKGROUND

Listeria monocytogenes is a foodborne pathogen that causes life-threatening infections in elderly, immunocompromised, and pregnant women. In pregnancy it may cause fetal loss or a preterm delivery, and the neonate is prone to neonatal sepsis and death.

METHODS

We created a cohort of all L. monocytogenes cases during 10 years (1998-2007) in Israel, by a comprehensive review of cases in hospitals throughout the country and cases reported to the Ministry of Health.

RESULTS

One hundred sixty-six pregnancy-related listeriosis cases were identified, resulting in a yearly incidence of 5-25 cases per 100 000 births. Presentation associated with fetal demise was more common in the second trimester (55.3%), and preterm labor (52.3%) and abnormal fetal heart rate monitoring (22.2%) were more common in the third trimester (P = .001). Fetal viability was low in the second trimester (29.2%) and much higher (95.3%) in the third trimester. Each additional week of pregnancy increased the survival chance by 33% (odds ratio, 1.331 [95% confidence interval, 1.189-1.489]). A single case of maternal mortality was identified. Listeria monocytogenes serotype 4b was more common in pregnancy-related than in non-pregnancy-related cases (79.5% vs 61.3%, P = .011). Pulsed-field gel electrophoresis analysis suggested that 1 pulsotype is responsible for 35.7% of the pregnancy cases between 2001 and 2007. This clone is closely related to the Italian gastroenteritis-associated HPB2262 and the invasive US Scott A L. monocytogenes strains.

CONCLUSIONS

Our survey emphasizes the high rate of pregnancy-related listeriosis in Israel and shows that specific clones might account for this.

False negative β-2 transferrin in the diagnosis of cerebrospinal fluid leak in the presence of Streptococcus pneumoniae

OBJECTIVES/HYPOTHESIS

The objectives of this study were to examine the presence of β-2 transferrin (β2TRNSF) in cerebrospinal fluid (CSF) contaminated in vitro by various bacteria and explore the mechanism (passive or active) responsible for β2TRNSF elimination. Early diagnosis of CSF leakage may change treatment decisions and minimize the risk of meningitis and encephalitis. β2TRNSF is a protein present exclusively in CSF. Its detection is highly useful in cases of CSF leakage, although it has never been examined in the presence of central nervous system infection.

STUDY DESIGN

Prospective patient analysis.

METHODS

Sterile CSF drawn from patients was contaminated in vitro with several microorganisms chosen for their ability to cause neurosurgical-related infections: Streptococcus pneumoniae, methicillin-sensitive Staphylococcus aureus, Staphylococcus epidermidis, and Pseudomonas aeruginosa. β2TRNSF was examined at two time points: following immediate inoculation (t0) and following an overnight incubation (t18) over various bacterial concentrations. Samples of CSF inoculated with S pneumoniae were also examined in the presence of ciprofloxacin. For β2TRNSF analysis we used immunoblotting electrophoresis and enzyme-linked immunosorbent assay (ELISA).

RESULTS

CSF samples collected from nine patients were analyzed. β2TRNSF was not detected following S pneumoniae inoculation at both time points when immunoblotting electrophoresis was used. Quantitative analysis using ELISA demonstrated significant β2TRNSF concentration decrease. The addition of ciprofloxacin led to the same results.

CONCLUSIONS

CSF leak detection using β2TRNSF may be deceiving in the presence of a S pneumoniae cerebral nervous system infection. A passive process is suggested, as β2TRNSF disappeared either immediately or following incubation with inactive bacteria.

Epidemiology of infective endocarditis in a tertiary-center in Jerusalem: a 3-year prospective survey

BACKGROUND

Epidemiological features of infective endocarditis have changed during the last decades because of increases in the prevalence of health care exposure and of Staphylococcus aureus bloodstream infection. Consequently, the role of surgery is evolving. We aim to provide a contemporary profile of epidemiological, microbiological, and clinical features of infective endocarditis in a tertiary medical center, and identify predictors of mortality.

METHODS

A prospective observational cohort study of consecutive adult patients with definite endocarditis according to the modified Duke criteria. Data were collected from January 1, 2009 through October 31, 2011 following a predefined case report form designed by the ICE-PCS.

RESULTS

Among 70 endocarditis episodes, 25.7% involved prosthetic valves and 11.5% were device related. Forty-four percent of episodes were health-care associated. The predominant causative microorganism on native valve, prosthetic valve and device related endocarditis was Staphylococcus aureus (33.3%). Viridans group streptococci accounted for the majority of community-acquired endocarditis (36.1%). At least one complication occurred in 50% of the episodes. One third of the patients who had an indication for surgery were operated upon. Six month case fatality ratio was 40%. Sixty-five percent of patients with a contraindication to surgery died, compared with 9% and 28.5% who were treated surgically and medically, respectively. In multivariable analysis, age was a predictor of mortality.

CONCLUSION

Compared with other series, we observed more health-care associated endocarditis, and a higher mortality. Nearly half of all deaths were in patients who had a contraindication to surgery. Careful evaluation of contraindications to surgery is warranted.

Rapid identification of Enterobacter hormaechei and Enterobacter cloacae genetic cluster III

AIM

Enterobacter cloacae complex bacteria are of both clinical and environmental importance. Phenotypic methods are unable to distinguish between some of the species in this complex, which often renders their identification incomplete. The goal of this study was to develop molecular assays to identify Enterobacter hormaechei and Ent. cloacae genetic cluster III which are relatively frequently encountered in clinical material.

METHODS AND RESULTS

The molecular assays developed in this study are qPCR technology based and served to identify both Ent. hormaechei and Ent. cloacae genetic cluster III. qPCR results were compared to hsp60 sequence analysis. Most clinical isolates were assigned to Ent. hormaechei subsp. steigerwaltii and Ent. cloacae genetic cluster III. The latter was proportionately more frequently isolated from bloodstream infections than from other material (P < 0·05).

CONCLUSION

The qPCR assays detecting Ent. hormaechei and Ent. cloacae genetic cluster III demonstrated high sensitivity and specificity.

SIGNIFICANCE AND IMPACT OF THE STUDY

The presented qPCR assays allow accurate and rapid identification of clinical isolates of the Ent. cloacae complex. The improved identifications obtained can specifically assist analysis of Ent. hormaechei and Ent. cloacae genetic cluster III in nosocomial outbreaks and can promote rapid environmental monitoring. An association was observed between Ent. cloacae cluster III and systemic infection that deserves further attention.

Contamination of hypertonic saline solutions in use by cystic fibrosis patients in Israel

BACKGROUND

Treatment of cystic fibrosis (CF) patients with inhaled hypertonic saline (HS) solutions is safe, beneficial and reduces exacerbation rates. We studied contamination of solutions used by Israeli CF patients for prolonged periods.

METHODS

The study addressed whether daily opening of previously unopened solutions caused contamination, survival of 6 CF-associated bacteria in artificially inoculated solutions, in-use contamination of solutions and patterns of their use by patients.

RESULTS

Repeated opening did not contaminate solutions and survival of indicator bacteria was variable. Mycobacterium abscessus survived in 3% HS solution for 6 weeks and Burkholderia cenocepacia and Pseudomonas aeruginosa were longer. In 30/76 (39.5%) of used solutions 49 contaminants were found, none being common CF-associated pathogens.

CONCLUSIONS

Most CF-related bacteria survived to some degree in HS. Approximately 40% of solutions used by patients were contaminated by organisms of uncertain significance. Our findings highlight the potential risk posed by contamination of HS solutions and support recommendations to use sterile unit-dose formulations.

Vaccination, herd behavior, and herd immunity

BACKGROUND

During the 2009 outbreak of novel influenza AH1N1, insufficient data were available to adequately inform decision makers about benefits and risks of vaccination and disease. We hypothesized that individuals would opt to mimic their peers, having no better decision anchor. We used Game Theory, decision analysis, and transmission models to simulate the impact of subjective risks and preference estimates on vaccination behavior.

METHODS

We asked 95 students to provide estimates of risk and health state valuations with regard to AH1N1 infection, complications, and expectations of vaccine benefits and risks. These estimates were included in a sequential chain of models: a dynamic epidemic model, a decision tree, and a population-level model. Additionally, participants' intentions to vaccinate or not at varying vaccination rates were documented.

RESULTS

The model showed that at low vaccination rates, vaccination dominated. When vaccination rates increased above 78%, nonvaccination was the dominant strategy. We found that vaccination intentions did not correspond to the shift in strategy dominance and segregated to 3 types of intentions: regardless of what others do 29/95 (31%) intended to vaccinate while 27/95 (28%) did not; among 39 of 95 (41%) intention was positively associated with putative vaccination rates.

CONCLUSIONS

Some people conform to the majority's choice, either shifting epidemic dynamics toward herd immunity or, conversely, limiting societal goals. Policy leaders should use models carefully, noting their limitations and theoretical assumptions. Behavior drivers were not explicitly explored in this study, and the discrepant results beg further investigation. Models including real subjective perceptions with empiric or subjective probabilities can provide insight into deviations from expected rational behavior and suggest interventions in order to provide better population outcomes.

Déjà vu: Ralstonia mannitolilytica infection associated with a humidifying respiratory therapy device, Israel, June to July 2011

Following a bloodstream infection in June 2011 with Ralstonia mannitolilytica in a premature infant treated with a humidifying respiratory therapy device, an investigation was initiated at the Hadassah Medical Centres in Jerusalem. The device delivers a warmed and humidified mixture of air and oxygen to patients by nasal cannula. The investigation revealed colonisation with R. mannitolilytica of two of 15 patients and contamination of components of five of six devices deployed in the premature units of the Hadassah hospitals. Ten isolates from the investigation were highly related and indistinguishable from isolates described in an outbreak in 2005 in the United States (US). Measures successful in containing the US outbreak were not included in user instructions provided to our hospitals by the distributor of the device.

Déjà vu: Ralstonia mannitolilytica infection associated with a humidifying respiratory therapy device, Israel, June to July 2011

Following a bloodstream infection in June 2011 with Ralstonia mannitolilytica in a premature infant treated with a humidifying respiratory therapy device, an investigation was initiated at the Hadassah Medical Centres in Jerusalem. The device delivers a warmed and humidified mixture of air and oxygen to patients by nasal cannula. The investigation revealed colonisation with R. mannitolilytica of two of 15 patients and contamination of components of five of six devices deployed in the premature units of the Hadassah hospitals. Ten isolates from the investigation were highly related and indistinguishable from isolates described in an outbreak in 2005 in the United States (US). Measures successful in containing the US outbreak were not included in user instructions provided to our hospitals by the distributor of the device.

RheoDSC Analysis of Hardening of Semi-Crystalline Polymers during Quiescent Isothermal Crystallization

The crystallization of semi-crystalline polymers is often analyzed by rheometry and calorimetry. By rheometry the viscosity evolution during crystallization can be followed, whereas from a calorimetric measurement, the evolution of the degree of crystallinity can be calculated. The time evolution of these material properties is valuable input for polymer processing simulation software and in order to combine the data in a reliable manner, hardening curves are used as a characterization tool. Such a hardening curve correlates the relative increase of the viscosity resulting from crystallization, to the advancing degree of crystallinity. In this study, these are extracted from simultaneous measurements on one sample using a RheoDSC device. The RheoDSC technique allows for the direct combination of the rheological and calorimetric signal without the need of combining separate stand-alone measurement results. In this study, isothermal crystallization experiments are used to discuss the benefits of this approach. This will lead to the recommendation that measuring the hardening effect in steady shear measurements at very low shear rates in a direct combined RheoDSC setup is the most reliable method to compile unambiguously a material specific hardening curve for semi-crystalline polymers.

Antagonisms between Surfactants: The Case of Laundry Detergents

Interaction between surfactants forms micelles that typically lead to a reduction of the irritation potential of the mixture. The objective of this study is to illustrate that such antagonism between surfactants is applicable to actual cases of consumer products e.g. laundry detergent products. The Zein test is an in vitro assay measuring corn protein denaturation by solutions of surfactant(s) and often used to predict their acute irritation potential. The Zein test data for the surfactant mixtures from nine representative laundry detergents demonstrate that the protein denaturation by the mixtures is, in all cases, lower than the cumulative score of protein denaturation by the different surfactants tested separately. The data clearly indicate that antagonism occurs between the actual surfactants present in their exact proportions as found in the consumer laundry detergent products. These data support the view that the hazard classification of detergent products as (irritant) by the dangerous preparation directive should not be based on a simple cumulative score of the irritation properties of the individual components of the products.

Dynamics of childhood invasive meningococcal disease in Israel during a 22-year period (1989-2010)

AIM

To describe the dynamics in the incidence of childhood invasive meningococcal disease (IMD) in Israel during a 22-year period (1989-2010).

METHODS

A longitudinal prospective surveillance in all 27 medical centers with pediatric services in Israel. All cases of children <15 years old with positive blood/cerebrospinal fluid (CSF) culture for Neisseria meningitidis were reported. Demographic, clinical, and bacteriological data were recorded. Meningococcal vaccine was not routinely given to Israeli children during the study period.

RESULTS

The mean age ± standard deviation (SD) among the 743 cases was 40.7 ± 40.2 months. The mean yearly incidence/100,000 was 2.0 ± 0.8. Age-specific incidences were 8.7 ± 2.8, 2.9 ± 1.5, and 0.8 ± 0.5 for children <1, 1-4, and >4 years old, respectively. The overall incidence decreased significantly from 3.7 in 1989 to 1.5 in 2010. Meningitis constituted 69.2 % of all cases. The most common serogroups were: B (76.9 %), C (10.9 %), Y (8.0 %), and W(135) (2.9 %). 78.6 % of all serogroup B isolates were from children <5 years old (p < 0.01). Serogroup C was found mainly in children ≥5 years old (63.4 %). The case fatality rates (CFRs) for children <1, 1-4, >4 years old, and the total study population were 9.2, 12.3, 7.7, and 9.9 %, respectively. CFRs were higher for children without meningitis (14.9 %) compared to children with meningitis (7.9 %) (p < 0.01).

CONCLUSIONS

Overall, and for serogroups B and W135, childhood IMD rates decreased significantly in Israel during the study period, without routine vaccine usage. The most common serogroup in all age groups was B, which was most prevalent in children <5 years old. No change in the trend of the overall CFR was noted during the study period.

Interactions between Scenedesmus and Microcystis may be used to clarify the role of secondary metabolites

Microcystis sp. are major players in the global intensification of toxic cyanobacterial blooms endangering the water quality of freshwater bodies. A novel green alga identified as Scenedesmus sp., designated strain huji (hereafter S. huji), was isolated from water samples containing toxic Microcystis sp. withdrawn from Lake Kinneret (Sea of Galilee), Israel, suggesting that it produces secondary metabolites that help it withstand the Microcystis toxins. Competition experiments suggested complex interaction between these two organisms and use of spent cell-free media from S. huji caused severe cell lysis in various Microcystis strains. We have isolated active metabolites from the spent S. huji medium. Application of the concentrated allelochemicals interfered with the functionality and perhaps the integrity of the Microcystis cell membrane, as indicated by the rapid effect on the photosynthetic variable fluorescence and leakage of phycobilins and ions. Although some activity was observed towards various bacteria, it did not alter growth of eukaryotic organisms such as the green alga Chlamydomonas reinhardtii.

Continuous surveillance to reduce extended-spectrum β-lactamase Klebsiella pneumoniae colonization in the neonatal intensive care unit

BACKGROUND

Clinical illness caused by resistant bacteria usually represents a wider problem of asymptomatic colonization. Active surveillance with appropriate institution of isolation precautions represents a potential mechanism to control colonization and reduce infection. The neonatal intensive care unit (NICU) is an environment particularly appropriate for such interventions. Neonates are rarely colonized by resistant bacteria on admission and staff enthusiasm for infection control is high.

OBJECTIVE

To reduce extended-spectrum β-lactamase-producing Klebsiella pneumoniae (ESBL-KP) acquisition amongst neonates through a continuous active surveillance intervention.

METHODS

Fecal ESBL-KP cultures were performed weekly on all neonates over 4 years. Neonates with positive cultures were managed with contact precautions by dedicated nurses separately from other neonates. ESBL-KP acquisition amongst neonates staying >7 days was compared for the consecutive years. A subset of ESBL-KP isolates was typed with pulsed-field gel electrophoresis (PFGE).

RESULTS

Surveillance cultures were obtained from 1,482/1,763 (84%) neonates over 4 years. ESBL-KP acquisition decreased continuously from 94/397 (24%) neonates in 2006 to 33/304 (11%) in 2009 (p < 0.001, hazard ratio 0.75, 95% confidence interval 0.66-0.85, p < 0.001 for comparison of years). Hospital-wide ESBL-KP acquisition did not decrease outside the NICU. PFGE identified identical ESBL-KP strains from multiple neonates on six occasions and different strains from single neonates on seven occasions.

CONCLUSIONS

ESBL-KP is probably both imported into and spread within the NICU. Continuous long-term surveillance with cohorting was associated with a decrease in ESBL-KP acquisition within the NICU. This low-risk intervention should be considered as a means to decrease neonatal acquisition of resistant bacteria.

[The effect of an intervention on rates of central vascular catheter-related bloodstream infection in intensive care units at the Hadassah Medical Center]

INTRODUCTION

Catheter-related bloodstream infection (CR-BSI) is a significant source for morbidity and mortality in addition to increased hospital costs. Patients in intensive care units (ICUs) have a greater risk for CR-BSI. Continuous monitoring and control of intravascular central catheters insertion (CCI) by using checklists have a key role in reducing the rate of infections and improving patient health care quality and safety.

OBJECTIVES

To determine the rate of CR-BSI, and to evaluate the adherence of ICU teams to infection control guidelines during CCI prior to and following an intervention program in ICU patients.

METHODS

The present study was conducted in six ICUs at the Hadassah Medical Center, during a period of 15 months. The rate of CR-BSI was determined in 320 patients with central catheters during the first period of the study. Assessment of adherence to infection control guidelines during CCI was carried out by observations. Educational intervention consisted of the introduction of physician guidelines for CCI, implementing a checklist to ensure adherence to the guidelines and lectures for the teams, beginning in the second period of the study. During the third period of the study, the rate of CR-BSI was determined in 336 patients with central catheters in the same ICUs, by the same research methods.

RESULTS

Following the intervention, a significant reduction in the rate of CR-BSI was observed in the study population from 9.66 to 3.63 infections per 1000 catheter days, with 62.4% risk reduction for CR-BSI, (P < 0.001). Improvements were also recorded in the CCI process and the rate of compliance of the ICUs team with infection control guidelines.

CONCLUSIONS

The implementation of a simple and inexpensive intervention reduced the rate of CR-BSI, leading to improved process of insertion of these catheters.

DISCUSSION

The continuous monitoring of the rate of CR-BSI and using checklists in every CCI process may reduce the morbidity, mortality, hospital stay, and lower hospital costs associated with centrally placed vascular catheters.

Training laboratory technicians from the Ethiopian periphery in the MODS technique enables rapid and low-cost diagnosis of Mycobacterium tuberculosis infection

Tuberculosis (TB) is a leading cause of morbidity and mortality and is frequently complicated by emergence of drug-resistant strains. Diagnosis of TB in developing countries is often based on the relatively insensitive acid-fast staining that does not enable susceptibility profiling. Microscopic observation drug susceptibility assay (MODS) is an inexpensive, simple method that enables rapid TB culture coupled with susceptibility testing. A 3-week MODS training of three Ethiopian laboratory technicians was conducted at Hadassah-Hebrew University Medical Center, Israel. Results of the trainee readings were blindly assessed by an experienced instructor. Two hundred fifty-five (255) trainee culture readings were evaluated throughout the course. The sensitivity and specificity were 75-100% and 31.5-100%, respectively. Multivariate analysis revealed that sensitivity and duration of incubation were positively correlated, although specificity was positively correlated with the length of training. MODS can be reliably performed by laboratory technicians inexperienced in culture techniques in developing countries, with high sensitivity and specificity reached after a brief learning period.

Comparison of two carbapenem-resistant Klebsiella pneumoniae clones: from a contained outbreak in a paediatric population and from a national epidemic

OBJECTIVES

A refractory epidemic of carbapenem-resistant Klebsiella pneumoniae (CRKP) emerged in the adult population at our hospital in 2005, as in most Israeli hospitals. Contemporaneously, a different clone of CRKP caused an easily contained outbreak in a paediatric long-term care facility (LTCF) in Jerusalem. While previously identified host-related risk factors for colonization by these organisms undoubtedly contributed to these outbreaks, it is very likely that bacterial factors might be crucial in explaining the striking differences in transmissibility between the implicated strains. We therefore sought bacterial factors associated with these different epidemiological behaviours.

METHODS

Seven CRKP isolated at our hospital and the LTCF during 2008-09 were examined by antimicrobial susceptibility testing and PFGE, and further analyses of these two clones was done using multilocus sequence typing and competition experiments. Plasmids were analysed by conjugation, restriction mapping, PCR and sequencing.

RESULTS

Both clones were multidrug resistant and harboured identical plasmids carrying the bla(KPC-3) gene. The hyper-transmissible epidemic clone carried additional antibiotic resistance genes and hosted an additional plasmid. The clone from the LTCF did not demonstrate hyper-transmissible properties despite its presence in an institution of a type commonly plagued by the epidemic clone. Competition assays showed the more easily contained strain to be fitter.

CONCLUSIONS

These findings suggest that neither the presence of the plasmid carrying the bla(KPC-3) gene nor relative survival fitness account for the hyper-transmissibility of the epidemic strain. The role of patient age in susceptibility to colonization by the epidemic strain should be investigated.

Destruction and formation of PCDD/Fs in a fluidised bed combustor co-incinerating automotive shredder residue with refuse derived fuel and wastewater treatment sludge

During an eight day trial automotive shredder residue (ASR) was added to the usual waste feed of a Fluidized Bed Combustor (FBC) for waste-to-energy conversion; the input waste mix consisted of 25% ASR, 25% refuse-derived fuel (RDF) and 50% wastewater treatment (WWT) sludge. All inputs and outputs were sampled and the concentration of the 17 PCDD/Fs with TEF-values was determined in order to obtain "PCDD/F fingerprints". The ASR contained approximately 9000 ng PCDD/Fs/kg(DW), six times more than the RDF and 10 times more than the WWT sludge. The fingerprint of ASR and RDF was dominated by HpCDD and OCDD, which accounted for 90% of the total PDDD/F content, whereas the WWT sludge contained relatively more HpCDFs and OCDF (together 70%). The flue gas cleaning residue (FGCR) and fly and boiler ash contained approximately 30,000 and 2500 ng PCDD/Fs/kg(DW), respectively. The fingerprints of these outputs were also dominated by HpCDFs and OCDF. The bottom ash contained only OCDD and OCDF, in total 8 ng PCDD/Fs/kg (DW). From the comparison of the bottom ash fingerprints with the fingerprints of the other output fractions and of the inputs, it could be concluded that the PCDD/Fs in the waste were destroyed and new PCDD/Fs were formed in the post combustion process by de novo synthesis. During the ASR-co-incineration, the PCDD/F congener concentrations in the fly and boiler ash, FGCR and flue gas were 1.25-10 times higher compared to the same output fractions generated during incineration of the usual waste mix (70% RDF and 30% WWT sludge). The concentration of the higher chlorinated PCDD/Fs increased most. As these congeners have the lowest TEF-factors, the total PCDD/F output, expressed in kg TEQ/year, of the FBC did not increase significantly when ASR was co-incinerated. Due to the relatively high copper levels in the ASR, the copper concentrations in the FBCs outputs increased. As copper catalysis the de novo syntheses, this could explain the increase in PCDD/F concentrations in these outputs.

Ongoing epidemic of Mycoplasma pneumoniae infection in Jerusalem, Israel, 2010 to 2012

A substantial epidemic of Mycoplasma pneumoniae infection was reported in late 2011 in some European countries. We report here an epidemic of M. pneumoniae infection that began in Jerusalem during 2010 and is still ongoing. This report complements current information on what might be a worldwide epidemic of M. pneumoniae infection that might require substantial coordinated international public health intervention.

Ongoing epidemic of Mycoplasma pneumoniae infection in Jerusalem, Israel, 2010 to 2012

A substantial epidemic of Mycoplasma pneumonia infection was reported in late 2011 in some European countries. We report here an epidemic of M. pneumonia infection that began in Jerusalem during 2010 and is still ongoing. This report complements current information on what might be a worldwide epidemic of M. pneumoniae infection that might require substantial coordinated international public health intervention.

Automotive shredder residue (ASR): reviewing its production from end-of-life vehicles (ELVs) and its recycling, energy or chemicals' valorisation

ASR is in Europe classified as hazardous waste. Both the stringent landfill legislation and the objectives/legislation related to ELV treatment of various countries, will limit current landfilling practice and impose an increased efficiency of the recovery and recycling of ELVs. The present paper situates ASR within the ELV context. Primary recovery techniques recycle up to 75% of the ELV components; the remaining 25% is called ASR. Characteristics of ASR and possible upgrading by secondary recovery techniques are reviewed. The latter techniques can produce a fuel- or fillergrade ASR, however with limitations as discussed. A further reduction of ASR to be disposed of calls upon (co-)incineration or the use of thermo-chemical processes, such as pyrolysis or gasification. The application in waste-to-energy plants, in cement kilns or in metallurgical processes is possible, with attention to the possible environmental impact: research into these impacts is discussed in detail. Pyrolysis and gasification are emerging technologies: although the sole use of ASR is debatable, its mixing with other waste streams is gradually being applied in commercial processes. The environmental impacts of the processes are acceptable, but more supporting data are needed and the advantage over (co-)incineration remains to be proven.

Assessment of the impact on human health of industrial emissions to air: does the result depend on the applied method?

The impact on human health of substances emitted to air by the Flemish industry was calculated with characterization factors (CFs) provided by the CML, Eco-indicator 99, EPS, EDIP and USEtox impact assessment methods. A comparison of the results pointed out that the choice of the CFs can greatly influence conclusions on the trend of the impact over time and on the relative contribution of the individual substances. If the impact on human health of organic substances and heavy metals was assessed separately, the differences between methods were less pronounced. In this case, the impacts on human health obtained by simply dividing the emitted masses of substances by the respective minimal risk concentrations or minimal risk doses, were comparable to those calculated with the CFs of the model-based methods.

An outbreak of achromobacter xylosoxidans associated with ultrasound gel used during transrectal ultrasound guided prostate biopsy

PURPOSE

We describe an outbreak of Achromobacter xylosoxidans after transrectal ultrasound guided prostate biopsy at a urology unit at a tertiary care center as well as clinical and microbiological investigation, and intervention.

MATERIALS AND METHODS

In September 2008, several days after undergoing transrectal ultrasound guided prostate biopsy, 4 patients were hospitalized with fever. We reviewed the procedure and infection control practices in the urology service. Environmental cultures were obtained from equipment and materials used for the procedure. Isolates were identified by routine laboratory procedures with molecular confirmation and characterized by pulsed field gel electrophoresis.

RESULTS

A. xylosoxidans was isolated from the urine of 2 patients, of whom 1 also had a positive blood culture. Review of transrectal ultrasound guided prostate biopsy revealed that the lubricant gel used in the procedure, which the biopsy needle passes through, was held in a plastic container that was repeatedly refilled from a large bag. A. xylosoxidans was isolated from this container. Pulsed field gel electrophoresis showed that the isolates obtained from patients and the gel were identical.

CONCLUSIONS

Contaminated lubricant gel was the cause of this outbreak. The practice of repeatedly refilling gel containers with nonsterile gel was replaced by the use of individual sterile gel sachets in each patient. No further cases occurred. During an invasive procedure involving a sterile body site, such as transrectal ultrasound guided prostate biopsy, using sterile gel is essential. Our experience emphasizes the crucial need to review all invasive procedures from an infection control perspective.

Mass balance for POPs in a real scale fluidized bed combustor co-incinerating automotive shredder residue

The European directive 2000/53/EC implies a "reuse and recovery" rate for end-of-life vehicles (ELVs) of 95% to be reached by the year 2015. One of the options to increase the actual average European "reuse and recovery" rate of approximately 78% (EU 15, 2008) is incineration of automotive shredder residue (ASR) with energy-recovery. The mass balance and the congener fingerprints for PCDD/Fs, dioxin-like PCBs, PCBs and PAHs in a real scale fluidized bed combustor (FBC) incinerating 25% ASR with 25% refuse derived fuel (RDF) and 50% waste water treatment sludge (WWT sludge) were investigated. The PCDD/F, dioxin-like PCB, PCB and PAH concentrations in this input waste mix were more than hundred times higher than in the usual waste feed of the incinerator (30% RFD and 70% WWT sludge). In the outputs of the FBC, however, the concentrations of these POP groups were comparable or only slightly higher than in the outputs generated during the incineration of the usual waste feed. The considered POPs in the waste were destroyed efficiently and the formation of new POPs during cooling of the flue gas appeared to a large extent independent of the POP concentrations in the incinerated waste.

Imported melioidosis, Israel, 2008

In 2008, melioidosis was diagnosed in an agricultural worker from Thailand in the southern Jordan Valley in Israel. He had newly diagnosed diabetes mellitus, fever, multiple abscesses, and osteomyelitis. Burkholderia pseudomallei was isolated from urine and blood. Four of 10 laboratory staff members exposed to the organism received chemoprophylaxis, 3 of whom had adverse events.

Mass balance for POPs in hazardous and municipal solid waste incinerators

The amount of different persistent organic pollutants (POPs) in the input of waste incinerators was compared to that in the output. Three cases were considered: a rotary kiln incinerating hazardous waste, a grate furnace incinerating municipal solid waste (MSW) and the same grate furnace co-incinerating plastics of waste of electrical and electronic equipment (WEEE) and automotive shredder residue (ASR) with MSW. The mass balance for PCBs in the rotary kiln indicates that these POPs are destroyed effectively during incineration. The grate furnace can be a sink or source of PCDD/Fs and PCBs depending on the concentrations in the incinerated waste. In order to compare the total amount of POPs in input and output, a methodology was developed whereby the amount of POPs was weighed according to minimal risk doses (MRDs) or cancer potency factors. For both incinerators the PCDD/Fs, PCBs and polyaromatic hydrocarbons (PAHs) are the main contributors to total weighed POP output. In MSW, the PCDD/Fs, PBDD/Fs and polybrominated diphenylethers (PBDEs) are the main contributors to the weighed POP input. The ratios of the weighed POP-input over -output clearly indicate that the rotary kiln incinerating hazardous waste is a weighed POP sink. The grate furnace incinerating MSW is a weighed POP sink or source depending on the POP-concentrations in the waste, but the difference between output and input is rather limited. When e.g. ASR and plastics of WEEE, containing high concentrations of PBDEs and PCBs, are co-incinerated in the grate furnace, it is clearly a weighed POP sink.

Vancomycin-resistant enterococci in long-term care facilities

Knowledge of the prevalence rates and associated risk markers of vancomycin-resistant enterococci (VRE) colonization among long-term care facility (LTCF) residents could be used to improve screening policies among newly admitted hospital inpatients. In a cross-sectional survey among 1,215 residents of LTCFs in Jerusalem, the VRE carriage rate was 9.6%. Previous hospitalization and antibiotic treatment were associated with elevated VRE colonization rate. In contrast, moderate and severe levels of dependency and prolonged stay in an LTCF were associated with a decrease in the VRE colonization rate.