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Biomedical subjects

S Ashkenazi

Publications and source records attributed to S Ashkenazi.

At least 19 recordsLinked to original sources
PubMed2006

The risk of hepatitis A infection among healthcare workers: a review of reported outbreaks and sero-epidemiologic studies.

All reports of hepatitis A (HA) outbreaks in healthcare settings published between 1975 and 2003 were studied to determine the background immunity or susceptibility of healthcare workers (HCWs) to HA. Twenty-six reports were found. The number of infected personnel ranged from one to 66 and, in most outbreaks, nurses accounted for the majority of personnel infected, reflecting high attack rates reaching 15-41%. In addition, we found 23 sero-epidemiological studies for HA among HCWs that had been performed in 13 different countries. Seroprevalence rates of HCWs with anti-HA antibody ranged between 4% among paramedical workers in Germany to 88% among hospital maintenance workers in Portugal. Effective infection control of HA outbreaks in hospitals demands early recognition, including awareness of atypical presentations of the infection, and strict adherence to universal infection control measures. Education programmes are of special importance for HCWs in neonatal, paediatric and intensive care units. The findings of the current study suggest that a pre-employment screening policy and administration of active vaccination to susceptible HCWs, particularly nurses, should be seriously considered in high-risk settings.

Adolescent↗
PubMed2004

Nitric oxide levels in preterm and term infants and in premature infants with bacteremia.

OBJECTIVE: To determine the serum nitric oxide levels in healthy neonates and in infants with bacteremia. METHODS: We performed a prospective study in a tertiary neonatal intensive care unit. The serum nitric oxide levels were measured in all infants at birth (basal) and in the infected neonates also on the first 2 days of bacteremia. RESULTS: Thirty-three neonates (10 term, 23 preterm) were included. Eleven preterm infants (mean gestational age 27 weeks) had bacteremia. The main blood culture isolates included coagulase-negative staphylococci (n=4), Klebsiella pneumoniae (n=3), and Escherichia coli (n=3). The serum nitric oxide levels increased during infection in 10 infants (p <0.008). The mean nitric oxide level before infection was 44 microM and during infection 96 microM (p=0.008). In the healthy babies, the mean nitric oxide level was 26 microM in those with a gestational age <27 weeks, 44 microM in those born between 28 and 36 weeks of gestation, and 63 microM in term infants. CONCLUSIONS: Bacteremic preterm infants produce significantly higher amounts of nitric oxide. The basal nitric oxide levels at birth may be correlated with gestational age.

Bacteremia↗
PubMed2004

Risk factors associated with candidaemia in the neonatal intensive care unit: a case-control study.

The incidence of candidaemia is steadily increasing in neonatal intensive care units (NICUs). Several neonatal risk factors for candidaemia have been identified, however, the number of cases in controlled studies is small and knowledge concerning maternal and perinatal risk factors is limited. The present study attempted to identify modifiable, independent maternal, perinatal and neonatal risk factors for candidaemia using a retrospective case-control study in the NICU of a tertiary-care paediatric medical centre. The study group consisted of 56 neonates admitted to the NICU between 1996 and 2000 who acquired candidaemia. The control group comprised the first infant admitted immediately after each study infant matched for gestational age (+/-10 days) and birthweight (+/-200 g). Potential maternal, perinatal and neonatal risk factors were compared between the groups using statistical methods and analysed by univariate and multivariate stepwise logistic regression models. The independent risk factors found to be significantly associated with increased risk of candidaemia were duration of ventilation and presence of bacteraemia before candidaemia. Maternal steroids had a significant protective effect. The positive predictive value using these three parameters was 78.38%. Maximizing in-utero steroid treatment in high-risk pregnancies, minimizing the days of mechanical ventilation and investment of efforts in prevention of bacteraemia may help to reduce the incidence of candidaemia in the NICU.

Analysis of Variance↗
PubMed2004

Seroepidemiology of varicella-zoster virus antibodies among health-care workers and day-care-centre workers.

Inclusion of live varicella vaccine in the routine occupational health vaccination schedule requires knowledge of the natural immunity to varicella zoster virus (VZV) among high-risk occupations. This study aims were to evaluate VZV antibody positivity among health-care workers (HCWs) and day-care-centre workers (DCWs) and to assess its association with potential risk factors. Three groups of workers were tested for VZV antibody positivity: hospitals and community clinic HCWs (n = 335), DCWs (n = 117) and blue-collar workers as controls (n = 121). The total VZV antibody positivity was 94.4%. There was no significant difference in VZV antibody positivity among study groups. DCWs had the lowest VZV seroprevalence (90.9%, 95% CI 85.7-96.1) and controls the highest (96.6%, 95% CI 93.2-99.9). This high VZV antibody positivity suggests that no special occupational measures are indicated in health-care or day-care occupational settings in Israel. On-going monitoring of the natural immunity to VZV is necessary to detect trends over time.

Adult↗
PubMed2004

Difficulties in making the diagnosis of Hirschsprung disease in early infancy.

This study highlights the less common presentations of Hirschsprung disease (HD) and HD-associated enterocolitis (HAE) in neonates and infants. We present three infants whose diagnosis was delayed because of atypical presenting features, especially with failure to gain weight, decreased appetite, episodes of diarrhoea and vomiting and hypoalbuminaemia. The reported incidence of HAE ranges from 0 to 16.2%. To avoid complications of life-threatening HAE, primary care physicians require a high index of suspicion of the more unusual presentations of HD in neonates and infants.

Colostomy↗
PubMed2004

[Judicious use of antibiotics in dental practice].

With the discovery of penicillin and entrance into the antibiotic era, the capability of dentists to treat dental infections have changed dramatically. Many antibacterial agents have developed since, but bacterial resistance using diverse mechanisms, have increased concomitantly. Since antimicrobial agents are frequently needed in dentistry, their judicious use is of prime importance. Dental infections can be divided to two main groups according to the origin of the infection. First, odontogenic infections (acute dento-alveolar abscess) originating from the dental pulp are most commonly caused by gram-positive anaerobic or facultative bacteria. Systemic antibiotic should be given concomitantly with drainage of the dento-alveolar abscess, debridment of the root canal of the infected tooth, and placement of inta-canal antimicrobial medication such as calcium hydroxide. Penicillin G, penicillin V (Rafapen) or amoxycillin (moxypen) are the first line systemic antimicrobial agents. In case of no improvement within 2-3 days, second line regimens such as amoxycillin-clavulanate (augmentin), cefuroxime (zinnat) or penicillin and metronidazole are recommended. In patients allergic to penicillin, clindamycinn (dalacin) is preferred over macrolides. The second group of infections originates from the periodontal apparatus, and is caused usually by gram-negative anaerobes bacilli, sometimes with Actinobacillus actinomycetemcomitance (Aa). Systemic antibiotics are only infrequently indicated in this situation, and always accompanied by scaling, root planning and curettage of the infected root and gingiva. In regenerative or post surgical periodontitis, augmentin, metronidazole or metronidazole in combination with penicillin or amoxycillin augmentin are recommended. In aggressive periodontitis the most common pathogen is Aa and therefore tetracycline, augmentin, or metronidazole and amoxicillin are recommended. In necrotizing ulcerative gingivitis, which is caused usually by fusiform bacilli and spirochetes, metronidazole or augmentin are appropriate. In patients with periodontal disease who are allergic to penicillin can be treated with a macrolides.

Aggregatibacter actinomycetemcomitans↗
PubMed2003

Hepatitis A virus seropositivity among hospital and community healthcare workers in Israel-the role of occupation, demography and socioeconomic background.

Hospital and community-clinic workers were tested for hepatitis A virus antibodies (HAV)-IgG to identify variables associated with presence of (HAV-IgG) and to determine whether sociodemographic background may explain all differences in HAV seropositivty among healthcare workers. Logistic regression analysis was used to identify variable associated with HAV-immunity. Multivariate logistic regression analysis revealed that HAV-seroprevalence correlated significantly (P<0.01) with age, siblings, residence in rural areas and origin. Nurse aides had an increased risk for HAV seropositivity (OR=5.04; 95% CI: 1.49-17.08) whereas physicians had a lower risk (OR=0.54: 95% CI: 0.30-0.98). Age and socioeconomic background were independently correlated with HAV immunity but did not explain all difference in HAV-seroprevalence. The higher susceptibility and elevated incidence of hepatitis A amongst physicians, prioritize primary prevention in this group.

Academic Medical Centers↗
PubMed2003

Nosocomial infections after cardiac surgery in infants and children: incidence and risk factors.

This prospective study was undertaken to determine the spectrum, sites and main risk factors for hospital-acquired infections (HAI) in our paediatric cardiothoracic intensive care unit (PCICU), and to determine the main organisms causing bloodstream infection in this setting. All patients admitted between January and December 1999 were prospectively followed for the development of HAI. To define risk factors, patients were grouped by age, complexity score, length of stay in PCICU, and whether the patient's chest was open or closed postoperatively. Three hundred and thirty-five patients underwent cardiac surgery. Fifty-five patients acquired 69 HAIs (HAI patient rate 16.4%). The most common HAI were bloodstream and surgical wound infection in 10 and 8%, respectively. The main causative organisms were Klebsiella spp.,Enterobacter spp. and Pseudomonas spp. in 22, 17 and 16% of episodes, respectively. Staphylococcus spp. accounted for 16% of episodes. The main risk factors for developing HAI were: neonatal age [P < 0.05, odds ratio (OR): 5.89, 95% confidence interval (CI): 2.96-11.58] prolonged PCICU stay (P < 0.05, OR: 6.82, 95% CI: 3.37-14.48), open chest postoperatively (P < 0.05, OR: 3.44, 95% CI: 1.31-8.52) and high complexity score (P < 0.05, OR: 4.03 95% CI: 1.87-8.43). The main causative organisms of bloodstream infections in children hospitalized in the PCICU differ from those in adult and pediatric general intensive care units (ICUs) and include mainly Gram-negative bacilli. High complexity score, neonatal age, prolonged ICU stay, and open chest postoperatively are risk factors of HAI in this patient population.

Catheterization, Central Venous↗
PubMed2002

Retrospective analysis of the first clonal outbreak of nalidixic acid-resistant Shigella sonnei shigellosis in Israel.

Reported here is a retrospective molecular analysis of the isolates recovered from the first outbreak of nalidixic acid (NA)-resistant Shigella sonnei shigellosis to occur in Israel. The outbreak affected 94 children. In the retrospective analysis, a total of 13 NA-resistant isolates and five NA-susceptible isolates recovered during the outbreak period were examined. Restriction fragment length polymorphism profiles obtained by digestion with BamHI, PvuI, HinfI or SmaI yielded identical profiles for all 18 isolates. All NA-resistant strains had an identical plasmid profile, but this profile differed from that displayed by the susceptible strains. In all of the NA-resistant strains a 304 bp fragment in the gyrA gene coding for a region associated with NA resistance was sequenced and showed a single point mutation, Ser83-->Phe. In this outbreak, the isolates of NA-resistant Shigella sonnei belonged to a single clone and NA resistance was associated with a point mutation in the gyrA gene.

Adolescent↗
PubMed2002

Changing distribution of Candida species isolated from sterile and nonsterile sites in Israel.

To determine if the prevalence of non- albicans Candida spp. has increased at two institutions in Israel, the distribution of 6,954 Candida isolates obtained from sterile and nonsterile sites during the periods 1995-1996 and 1999-2000 were compared. In the latter period, a slight decrease was observed in the prevalence of non- albicans Candida spp. isolated from sterile sites (from 39% to 37%) and nonsterile sites (from 38% to 35%). Specifically, the prevalence of Candida glabrata increased significantly in sterile sites, from 26% to 35% (P=0.0095), and in nonsterile sites, from 18% to 27% (P<0.0001), and the prevalence of Candida krusei increased significantly in sterile sites, from 2% to 7% (P=0.0072). The prevalence of Candida parapsilosis decreased significantly in nonsterile sites, from 31% to 23% (P=0.0002). Continuous surveys of the distribution of Candida spp. and analysis of the clinical significance of changes are warranted.

Candida↗
PubMed2002

Hepatitis B vaccination: long-term follow-up of the immune response of preterm infants and comparison of two vaccination protocols.

BACKGROUND: We conducted a 3-year follow-up study of long-term antibody persistence following vaccination of low-risk preterm infants with recombinant hepatitis B vaccine (HBV). Two three-dose protocols were compared: vaccination beginning within 24 h of birth to initial vaccination delayed until a weight of 2,000 g was reached. SUBJECTS AND METHODS: The study population included 136 children, divided into three groups: children born prematurely (< or = 35 weeks, n = 57), children born at term (> or = 37 weeks, n = 39), both groups receiving the first dose of HBV within 24 h of birth, and children born prematurely (< or = 35 weeks, n = 40), who received the first dose of HBV when a weight of 2,000 g was reached. All infants received the second hepatitis vaccination 1 month after the first, and the third dose 6 months after the first. Hepatitis B surface antibody (AntiHBs) was measured at an age of 3-3.5 years (at least 2.5 years after completion of the three-dose HBV series). An AntiHBs level of > or = 10 IU/l was considered positive. RESULTS: At 3-3.5 years of age, a higher percentage of the premature-delayed vaccination group had a positive AntiHBs level (92.5%) compared to both the premature (54.4%, p < 0.001) and full-term groups (71.8%, p < 0.05) vaccinated soon after birth. The premature-delayed vaccination group also had a significantly higher geometric mean concentration (GMC) (119 vs 14.2 IU/l, p < 0.001 and 119 vs 32.7 IU/l, p < 0.005, respectively). CONCLUSION: Delaying vaccination of premature infants against hepatitis B until a weight of 2,000 g was reached resulted in both a significantly higher percentage of children with positive antibody levels and a significantly higher GMC at 3-3.5 years of age as compared to early-vaccinated preterm and full-term infants. The known short-term advantage of delayed vaccination of preterm infants was shown to persist for at least the first 3 years of life.

Age Factors↗
PubMed2001

Long-term outcome of infective endocarditis: the impact of early surgical intervention.

To determine the impact of early surgical intervention on long-term survival in patients with infective endocarditis (IE), charts of all patients who had IE from January 1987 through December 1996 were reviewed. A total of 252 patients with definite or possible IE were included. Forty-four patients (17.5%) had early surgery on median hospital day 2 (range, 0-30 days), and 208 patients (82.5%) received medical treatment alone. On multivariate analysis, several variables, including early surgical intervention, improved long-term survival rates (hazard ratio, 1.5; P=.03), mainly in patients with Staphylococcus aureus etiology (P=.04). When patients with prosthetic devices were excluded, the median duration of survival for patients who had early surgery was >150 months, compared with 61.5 months for patients in the medical group (P=.1). Early surgical intervention compared with medical therapy alone is associated with increased short- and long-term survival rates in patients with IE, primarily when IE is caused by S. aureus.

Adolescent↗
PubMed2001

Early responses to nonconjugated polyribosylribitol phosphate challenge as evidence of immune memory after combined diphtheria-tetanus-pertussis-polio-Haemophilus influenzae type b primary vaccination.

OBJECTIVES: A high risk of invasive Haemophilus influenzae type b (Hib) disease exists in the first few years of life. A reduction in anti-polyribosylribitol phosphate (PRP) antibody concentrations follows the administration of certain diphtheria-tetanus-acellular pertussis (DTPa)-based Hib conjugate combined vaccines. However, these combined vaccines prime the immune memory, which is an important factor in protection. As yet there is no direct evidence of the time scale involved in the development of the immune memory post-primary vaccination. In this report we investigated the presence of immune memory at 10 and 12 months of age, 4 and 6 months after primary vaccination of young infants with a pentavalent combination of DTPa, inactivated poliovirus vaccine (IPV) and Hib (DTPa-IPV/Hib) vaccine. METHODS: In two trials (A and B) infants received DTPa-IPV combined with Hib-tetanus conjugate (PRP-T) vaccine at 2, 4 and 6 months of age. The presence of immune memory was assessed by measuring anti-PRP concentrations 7 to 10 days after a nonconjugated PRP challenge given at 10 months in Trial A and at 12 months in Trial B. RESULTS: Administration of a nonconjugated PRP challenge 4 and 6 months after primary vaccination in Trials A and B, respectively, elicited an increase in anti-PRP geometric mean concentrations (4.5 and 5.8 microg/ml, respectively) within 7 to 10 days. These concentrations exceed those reported in the literature involving unprimed children who had received a single dose of nonconjugated PRP at the same age. CONCLUSION: The results demonstrate the development of anti-PRP immune memory at an early age, 4 and 6 months after completion of a three dose primary vaccination course of combined DTPa-IPV/Hib vaccine. The ability of primed infants to mount a rapid response is an important observation given the high risk of Hib infection at this critical age.

Antibodies, Bacterial↗
PubMed2001

Mycetoma of the renal pelvis caused by Fusarium species.

A preterm infant, with posterior urethral valves had a mycetoma of the renal pelvis caused by Fusarium species. Prolonged treatment with amphotericin B alone or with flucytosine failed. Combined surgical drainage and medical therapy resulted in full resolution.

Adult↗
PubMed2001

Emergence of multiple human cytomegalovirus ganciclovir-resistant mutants with deletions and substitutions within the UL97 gene in a patient with severe combined immunodeficiency.

Infection with multiple ganciclovir-resistant human cytomegalovirus mutants, containing different substitutions and deletions in the UL97 gene, was found in a patient with severe combined immunodeficiency (SCID) within 3 weeks of ganciclovir therapy. A novel 11-codon deletion at positions 590 to 600 was identified. These unique findings may be related to the nature of the immunodeficiency in the SCID patient.

Amino Acid Substitution↗
PubMed2001

Safety and immunogenicity of improved Shigella O-specific polysaccharide-protein conjugate vaccines in adults in Israel.

Data suggest that the O-specific polysaccharide (O-SP) domain of the lipopolysaccharide (LPS) of Shigella species is both an essential virulence factor and a protective antigen and that a critical level of serum immunoglobulin G (IgG) to this antigen will confer immunity to shigellosis. Because covalent attachment of polysaccharides to proteins increases their immunogenicity, especially in infants and in young children, the O-SP of Shigella species were bound to medically useful proteins, and the safety and immunogenicity of the resultant conjugates were confirmed in adults and 4- to 7-year-old children. Succinylation of the carrier protein improved the immunogenicity of Shigella conjugates in mice and increased their yield. Based on these results, a clinical trial of O-SP conjugates of Shigella sonnei and Shigella flexneri 2a bound to succinylated mutant Pseudomonas aeruginosa exotoxin A (rEPAsucc) or native or succinylated Corynebacterium diphtheriae toxin mutant (CRM9 or CRM9succ) was conducted in healthy adults. The conjugates were safe and immunogenic. S. sonnei-CRM9, S. sonnei-CRM9succ, and S. sonnei-rEPAsucc elicited significant rises of geometric mean (GM) IgG anti-LPS within 1 week of injection (P < 0.001). At 26 weeks, the GM anti-LPS levels elicited by these three conjugates were similar and higher than their prevaccination levels (P < 0.0001). GM IgG anti-LPS levels elicited by S. flexneri 2a-rEPAsucc were significantly higher than those elicited by S. flexneri 2a-rCRM9succ at all intervals after injection. At 26 weeks, the levels of IgG anti-LPS in vaccinees were higher than their prevaccination levels (P < 0.0001). The serum antibody responses were specific, as there was no significant rise of anti-LPS to the heterologous O-SP in any vaccinee. Both conjugates elicited statistically significant rises of serum antibodies to the injected carrier protein. At 6 months, these five Shigella conjugates elicited higher fold rises than similar conjugates (D. N. Taylor et al., Infect. Immun. 61:3678-3687, 1993). Based on these data, we chose S. sonnei-CRM9 and S. flexneri 2a-rEPAsucc for evaluation in children.

Adolescent↗
PubMed2001

Successful treatment of antiepileptic drug hypersensitivity syndrome with intravenous immune globulin.

Intravenous immune globulin (IVIG) has proved beneficial for severe immunologically related cutaneous adverse reactions. We report a child with severe antiepileptic drug hypersensitivity syndrome who was successfully treated with IVIG. IVIG should be considered in the pharmacologic armamentarium of severe antiepileptic drug hypersensitivity syndrome. antiepileptic drugs, hypersensitivity, immune globulin.

Anticonvulsants↗