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Biomedical subjects

R Dagan

Publications and source records attributed to R Dagan.

At least 109 records · Page 6Linked to original sources
PubMed1997

[Gram-negative enteric bacteremia in children in the Negev (1989-1994)].

During 1989-1994, there were 322 episodes of Gram-negative enteric bacteremia in 308 children. The incidence increased from 31/100,000 in children younger than 15 years of age during 1989-1991, to 50/100,000 during 1992-1994. The most common pathogens were Klebsiella, E. Coli, Salmonella and Enterobacter. 39% of episodes were nosocomial and a significant increase was recorded for each species during the last 3 years of the study. Klebsiella represented the most common pathogen causing nosocomial bacteremia, while E. coli and Salmonella were the main pathogens causing community-acquired bacteremia. In this study in southern Israel, the incidence of Gram-negative enteric bacteremia was significantly higher in Bedouin children, with the exception of bacteremia due to Salmonella, which occurred mainly in Jewish children.

Adolescent↗
PubMed1997

[Epidemiologic characteristics of pediatric emergency room referral and hospitalization for diarrhea in the Negev].

Diarrheal diseases weigh heavily on the health of children, especially in developing countries, but also impose burdens on health care services worldwide. This study was performed to determine whether patterns of referrals in the Negev to the pediatric emergency room (PER) for diarrhea differ between the Jewish and Bedouin populations of the Negev, and the extent of the burden imposed on the PER and in-hospital services in the Negev. Characteristics of referrals and hospitalizations were examined from March 1994 to February 1995. Of the 27,834 referrals to the PER for children under 16, 2518 (9%) had diarrhea and there were 5,169 hospital admissions, 701 (13.6%). The annual rates of referral were 146 per 10,000 in Jews and 225 in Bedouin, giving an odds ratio (OR) of 1.5 (p < 0.001). for Bedouin. The rates of hospitalization were 23 per 10,000 in Jews and 99 in Bedouin (OR 4.4, p < 0.001). 1380 (54.8%) of the PER referrals were of infants under a year of age. For hospitalization, the annual rates were 164 per 10,000 in Jews and 756 in Bedouin (OR 4.9, p < 0.001). During June to August referrals and hospitalizations for diarrhea were significantly higher, and from December to February significantly lower than during the remaining months. These differences arise from the marked seasonal pattern in the Bedouin population, whereas in the Jewish population there was no seasonal variation. Even in the 90's the burden on health services in the Negev as a result of diarrheal illness is considerable and the Bedouin population still contributes to that burden disproportionately. There is need both to reduce the gap in referrals and hospitalization between the populations, as well as to reduce the rates, using currently available means such as education, while developing new technologies, such as vaccines.

Adolescent↗
PubMed1997

Immunogenicity and safety of a liquid combination of DTP-PRP-T [corrected] vs lyophilized PRP-T reconstituted with DTP.

The immunogenicity and safety of a combined diphtheria, tetanus, pertussis and Haemophilus influenzae type b-tetanus conjugate vaccine (DTP-PRP-T) was compared to the same combination obtained by the reconstitution of H. influenzae type b-tetanus conjugate vaccine lyophilized (PRP-T) with liquid diphtheria-tetanus-pertussis vaccine (DTP). Two hundred and sixty-two healthy infants were randomized to receive a intramuscular injection of 0.5 ml of one of the above combination vaccines at 2, 4 and 6 months of age, and a subgroup of 134 infants received a booster dose at 12 months. Serum antibody levels to each vaccine component were measured at ages 2, 6, 7, 12 and 13 months. Systemic and local reactions were assessed during the first 3 days after each injection by diary cards distributed to the parents. After the third dose and booster administered at 12 months of age, significant equivalence between the groups was observed, and the geometric mean titer of anti H. influenzae type b capsular polysaccharide (Hib-CP) antibodies were 5.9 and 32.6 micrograms ml-1 for the liquid combination group and 5.8 and 19.4 for the lyophilized group, respectively. After the third dose, anti-Hib-PC antibody levels of > or = 1.0 microgram ml-1 and 0.15 microgram ml-1 were seen in 94% and 100%, respectively, of the liquid combination group and 90 and 99%, respectively of the lyophilized group. After the booster dose, levels of > or = 1.0 microgram ml-1 were observed in 100% and 93.5% of the liquid combination group and the lyophilized combination group, respectively. Systemic and local reactions to the vaccination were generally mild and did not differ significantly between the groups. We conclude that the liquid combination of DTP-PRP-T is safe and at least as immunogenic as the lyophilized preparation. This liquid preparation, like other combined vaccines may be helpful for planning vaccination programs with a reduced number of injections.

Antibodies, Bacterial↗
PubMed1997

Echovirus type 22 outbreak associated with gastro-intestinal disease in a neonatal intensive care unit.

An echovirus type 22 outbreak involving 19 neonatal intensive care unit (NICU) patients during the months of October and November 1992 is reported. Twelve infants presented with diarrhea, 7 of whom had bloody stools and x-ray findings compatible with early stages of necrotizing enterocolitis, while one infant demonstrated characteristic pneumatosis intestinalis. Outbreaks of echovirus type 22 infection in premature infants have rarely been reported. The possibility of Echovirus 22 infection should be considered in neonatal gastrointestinal disease associated with features of necrotizing enterocolitis.

Antibodies, Viral↗
PubMed1997

Bacteriologic response to oral cephalosporins: are established susceptibility breakpoints appropriate in the case of acute otitis media?

Bacteriologic response to cefuroxime axetil and cefaclor administered for 10 days was evaluated in acute otitis media (AOM) in patients aged 6-36 months. Middle ear fluid culture was obtained by tympanocentesis before treatment, on day 4 or 5 after initiation of treatment, and if clinical relapse occurred before day 17. Bacteriologic failure was observed in 32% of patients receiving cefaclor versus 15% of patients receiving cefuroxime axetil (P = .009). Failure rates increased with increasing MIC: For Streptococcus pneumoniae, 0.5 microg/mL (established as cutoff value for cefuroxime by the National Committee for Clinical Laboratory Standards [NCCLS]) discriminated between success and failure. For Haemophilus influenzae, high failure rates were observed for cefaclor, even with low MICs (< or = 1.0 microg/mL), and with both drugs they tended to increase with increasing MIC, even for values below the cutoff suggested by the NCCLS (8.0 and 4.0 microg/mL for cefaclor and cefuroxime, respectively). Thus, for AOM caused by H. influenzae, lower susceptibility cutoff levels for MICs should be established.

Acute Disease↗
PubMed1997

Kingella kingae: an emerging cause of invasive infections in young children.

Kingella kingae, a fastidious hemolytic gram-negative bacillus once considered to be an exceptional cause of disease, has emerged in recent years as an important invasive pathogen in children. When synovial fluid and other exudates were inoculated into blood culture bottles, enhanced recovery of the organism was observed, and an annual incidence of invasive K. kingae infections of 27.4 per 100,000 children younger than age 24 months was demonstrated in southern Israel. Skeletal infections are the most common clinical presentation of K. kingae, and studies conducted in that region have shown that this organism is the most common etiology of septic arthritis in children below the age of 24 months. Other invasive diseases caused by K. kingae include bacteremia, endocarditis, and infections involving the lower respiratory tract, the eyes, or the central nervous system. Recent studies have demonstrated that K. kingae is part of the normal oropharyngeal flora of young children. Clinical data suggest that the organism may gain access to the bloodstream in the course of an upper respiratory infection or stomatitis. The organism is susceptible to a wide range of antimicrobial drugs, and with the exception of some cases of endocarditis, K. kingae infections in children usually run a benign clinical course.

Age Distribution↗
PubMed1997

Changing epidemiology of invasive Streptococcus pyogenes infections in southern Israel: differences between two ethnic population groups.

BACKGROUND: Two ethnic populations (westernized Jews and Bedouins in transition from semi-nomadic to sedentary life conditions) living in Southern Israel and receiving inpatient services in the only medical facility of the region. OBJECTIVE: To determine whether the incidence and severity of Streptococcus pyogenes infections among Jewish and Bedouin children have changed over the years. STUDY DESIGN: Retrospective (1980 to 1994), population-based. Medical charts of children younger than 15 years of age hospitalized with S. pyogenes bacteremia and/or severe invasive infection were reviewed. Incidence rates of bacteremia among Jewish and Bedouin children were calculated separately. RESULTS: The incidence of S. pyogenes bacteremia was 2.82/100,000 between 1980 and 1984, was 2.58/100,000 between 1985 and 1989 and rose significantly during 1990 through 1994 to 4.82/100,000 (P < 0.01). The observed increment was the result of a significant increase among the Jews, whereas the incidence among the Bedouin population remained relatively stable. Streptococcal toxic shock syndrome was diagnosed in three Jewish patients between 1992 and 1994. No predominance of any particular streptococcal M-type was observed. CONCLUSIONS: The incidence of pediatric S. pyogenes bacteremia has increased in Southern Israel in recent years. This increase has occurred among the Jewish population, among which the first cases of streptococcal toxic shock syndrome have recently occurred. The increased incidence observed is not the result of dissemination of a single virulent streptococcal clone.

Adolescent↗
PubMed1997

Safety and immunogenicity of a novel mammalian cell-derived recombinant hepatitis B vaccine containing Pre-S1 and Pre-S2 antigens in neonates.

BACKGROUND: Most of the licensed hepatitis B vaccines produced by recombinant DNA contain the S protein component of the hepatitis B virus surface antigen particle but lack two important components, Pre-S1 and Pre-S2. These components have recently been shown to play an important immunogenic role by enhancing the hepatitis B surface antibody (anti-HBs) titers, stimulating response and circumventing genetic nonresponsiveness. OBJECTIVE: To assess safety, tolerability and immunogenicity in neonates of a novel recombinant HBV vaccine (Bio-Hep-B) containing the S, Pre-S1 and Pre-S2 components compared with a licensed recombinant vaccine (Engerix-B) containing the S component only. METHODS: Healthy neonates were randomized to receive either Bio-Hep-B (2.5 micrograms/dose) or Engerix-B (10 micrograms/dose) at ages < 24 h, 1 month and 6 months. Blood was obtained at ages 0, 1, 7 and 12 months. Tolerability was assessed by diary cards filled by the parents for 5 successive days after immunization. Immunogenicity was assessed by determination of anti-HBs antibody. RESULTS: Of 205 neonates 153 were in the Bio-Hep-B group and 52 were in the Engerix-B group. Both vaccines were well-tolerated and all infants became seroprotected (anti-HBs > 10 mIU/ml). After the first dose a significantly higher proportion of neonates seroconverted in the Bio-Hep-B group than in the Engerix-B group (83% vs. 34%; P < 0.001); this difference in seroresponse was even more pronounced for those achieving seroprotective concentrations (> 10.0 mIU/ml) after the first dose: 54% vs. 7%, respectively (P < 0.001). Geometric mean concentrations were significantly higher at all points in the Bio-Hep-B group. CONCLUSION: Both vaccines were well-tolerated and immunogenic. Bio-Hep-B, despite its low dose, was significantly more immunogenic and elicited more rapid antibody response. This finding has implication for future vaccine programs in regions where maternal screening for hepatitis B virus surface antigen and administration of hepatitis B immunoglobulin are not routinely practiced at birth for infants of hepatitis B virus carrier mothers.

Female↗
PubMed1997

A prospective study of neonatal sepsis and meningitis in southern Israel.

OBJECTIVE: To study the epidemiology of neonatal sepsis and meningitis in the Negev area of southern Israel. DESIGN: A prospective 8-year study conducted at the neonatal intensive care unit and pediatric wards of the Soroka University Medical Center. RESULTS: Two hundred twenty-nine cases of hospital and community-acquired neonatal sepsis occurred during the study period. Thirty-two patients (14%) were meningitis. During this period 70,709 births (59% Jews and 41% Bedouins) were recorded; thus the rates of neonatal sepsis and meningitis were 3.2 and 0.5/1000 live births, respectively. One hundred seventeen (4/1000 live births) cases were recorded in Bedouins and 112 (2.6/1000 live births) in Jewish neonates (P < 0.001). Twenty-six percent of all sepsis cases occurred within < 24 h from birth, 25% from Days 2 to 7 of life and 49% between Days 8 and 28. A total of 251 organisms that were considered true pathogens were isolated. Fifty-seven of all isolates were Gram-negative organisms (mainly Klebsiella pneumoniae (20%) and Escherichia coli (16%)). Gram-positive organisms were isolated in 41% of cases. Although E. coli was the most frequently recovered Gram-negative pathogen in community-acquired late onset sepsis, Klebsiella and Enterobacter spp. represented the most commonly isolated Gram-negative organisms in nosocomial late onset sepsis. All Staphylococcus aureus isolates recovered in late onset sepsis were nosocomial. The incidence of Streptococcus agalactiae was 3 times higher in early onset sepsis than in late onset sepsis. All cases of Streptococcus pneumoniae sepsis occurred in Bedouins. CONCLUSIONS: Neonatal sepsis and meningitis rates in southern Israel are similar to those reported in Western Europe and the United States. The incidence of neonatal sepsis is significantly higher for Bedouins than for Jewish neonates. The distribution of the main pathogens is different in southern Israel and although Gram-negative enteric organisms are predominant, S. agalactiae plays a relatively minor role in the etiology of sepsis during the first month of life. In southern Israel the etiology of community-acquired late onset sepsis is different from that of nosocomial late onset sepsis.

Female↗
PubMed1997

Safety and immunogenicity of tetravalent pneumococcal vaccines containing 6B, 14, 19F and 23F polysaccharides conjugated to either tetanus toxoid or diphtheria toxoid in young infants and their boosterability by native polysaccharide antigens.

BACKGROUND: New vaccines against pneumococcal infections in infancy are needed. We assessed in young infants the safety and immunogenicity of two tetravalent vaccines containing pneumococcal 6B, 14, 19F and 23F polysaccharides conjugated to either tetanus toxoid (Pnc-T) or diphtheria toxoid (Pnc-D). METHODS: Pnc-T or Pnc-D containing 3 microg of polysaccharide of each of the four pneumococcal polysaccharides or placebo were given intramuscularly in a double blinded fashion (25 infants per group) at 2, 4 and 6 months of age. At 12 months of age all 75 children were boosted with a 23-valent nonconjugate polysaccharide pneumococcal vaccine. Serum type-specific anticapsular antibody concentrations were measured at 2, 4, 6, 7, 12 and 13 months of age. Adverse events occurring within 72 h after each injection were recorded. RESULTS: Both Pnc-T and Pnc-D were well-tolerated. Pnc-T and Pnc-D had higher antibody concentrations compared with placebo after primary immunity (type 6B, 1.66, 1.40 and 0.60 microg/ml, respectively; type 14, 4.81, 2.65 and 2.22 microg/ml, respectively; type 19F, 2.40, 3.48 and 0.83 microg/ml, respectively; type 23F, 0.96, 0.44 and 0.35 microg/ml, respectively). Proportions of infants with concentrations above 1.0 microg/ml were also higher in the vaccine recipients than in those given placebo. After booster with the nonconjugate polysaccharide vaccine, both geometric antibody concentration and proportion with concentrations > or =1.0 microg/ml were significantly higher among either Pnc-T or Pnc-D recipients than among placebo recipients. CONCLUSIONS: Both Pnc-T and Pnc-D were well-tolerated, induced serotype-specific anticapsular antibodies and induced immunologic memory.

Antibodies, Bacterial↗
PubMed1997

Reduction of pneumococcal nasopharyngeal carriage in early infancy after immunization with tetravalent pneumococcal vaccines conjugated to either tetanus toxoid or diphtheria toxoid.

BACKGROUND: Pneumococcal nasopharyngeal colonization is important for transmission of the organisms. We assessed the ability of two tetravalent conjugate vaccines administered in early infancy to prevent carriage of vaccine-related pneumococci. METHODS: A vaccine containing pneumococcal type 6B, 14, 19F and 23F polysaccharide conjugated to tetanus toxoid (Pnc-T) and a vaccine containing the same four polysaccharides conjugated to diphtheria toxoid (Pnc-D) were compared with placebo, in a double blinded study (25 infants per group). Vaccines (or placebo) were injected at 2, 4 and 6 months of age. At 12 months of age a native (nonconjugate) polysaccharide vaccine was administered as a booster. Serum type-specific anticapsular antibody concentrations were measured and nasopharyngeal cultures were obtained at 2, 4, 6, 7, 12 and 13 months of age. RESULTS: In general carriage of all pneumococci (vaccine- and non-vaccine-related) was low at age 2 months and increased with age. However, for the vaccine-related serotypes (6A, 6B, 14, 19F and 23F) carriage was not increased with age in Pnc-D or Pnc-T recipients. Of all cultures obtained after the full primary series, 7 of 72 (10%), 3 of 62 (5%) and 19 or 70 (27%) were positive for the vaccine-related pneumococcal serotypes among the Pnc-D, Pnc-T and placebo recipients, respectively (P = 0.001 for Pnc-D vs. placebo; P = 0.014 for Pnc-T vs. placebo). Most of the antibiotic-resistant isolates belonged to the vaccine-related serotypes. CONCLUSIONS: A significant reduction in the carriage of vaccine-related strains after administration of conjugate vaccines was observed. These preliminary results suggest that transmission of specific pneumococcal serotypes most often associated with disease and antibiotic resistance may at least partially be controlled by immunization.

Bacterial Vaccines↗
PubMed1997

Safety and immunogenicity of a combined pentavalent diphtheria, tetanus, acellular pertussis, inactivated poliovirus and Haemophilus influenzae type b-tetanus conjugate vaccine in infants, compared with a whole cell pertussis pentavalent vaccine.

BACKGROUND: We compared the safety and immunogenicity of two combined diphtheria-tetanus-pertussis-inactivated poliovirus vaccines containing either acellular (Pa, SmithKline Beecham Biologicals) or whole cell (Pw, Pasteur Merieux Connaught) pertussis components, mixed with a Haemophilus influenzae type b polysaccharide polyribosylribitol phosphate-tetanus conjugate vaccine in an open, randomized study in healthy infants. DESIGN: The combined vaccines were given at 2, 4, 6 and 12 months of age, and serum samples were obtained at ages 2, 6, 7, 12 and 13 months. Adverse events were obtained by diary cards. RESULTS: The Pa group (n = 101) had a clearly lower incidence of both local and systemic adverse events than the Pw group (n = 100). Immunogenicity was comparable for the diphtheria and tetanus components, but significantly superior for pertussis toxin, filamentous hemagglutinin, pertactin and polioviruses 1, 2 and 3 in the Pa group. Both groups had an appropriate response with regard to H. influenzae type b polysaccharide polyribosylribitol phosphate, but the dynamics of the response were significantly different: geometric mean concentrations (micrograms per ml) after the second, third and booster doses were 1.27, 5.06 and 23.12 in the Pa group and 2.72, 6.66 and 13.59 in the Pw group, respectively (P = 0.0002 after second dose; P = 0.0005 after booster). CONCLUSION: The presently studied diphtheria, tetanus, acellular pertussis-H. influenzae b vaccine conjugated to tetanus toxoid combination was at least as immunogenic as the diphtheria, tetanus, whole cell pertussis-H. influenzae b vaccine conjugated to tetanus toxoid combination, with a significantly better safety profile. This is of obvious importance in countries where inactivated poliovirus vaccine is part of the routine infant immunization programs.

Antibodies, Bacterial↗
PubMed1997

Natural history of Giardia lamblia and Cryptosporidium infections in a cohort of Israeli Bedouin infants: a study of a population in transition.

The natural history of Giardia lamblia and Cryptosporidium infections were determined in a cohort of 164 Bedouin children, from a population not previously studied, which is in transition from nomadism to a settled life style. Stools were sampled monthly from birth to two years of age and at all diarrhea episodes. The risk of infection with G. lamblia and Cryptosporidium infection by age two was 91.5% and 48.8%, respectively. Cryptosporidium prevalence was 3-4% at all ages, whereas G. lamblia prevalence was > 30% after age one. Giardia lamblia and Cryptosporidium asymptomatic detection rates were high, 28.5% and 1.6%, respectively. Detection of G. lamblia was higher in diarrhea episode samples obtained before six months of age, but after that age and overall, the detection was lower than in nondiarrhea samples (odds ratio [OR] = 0.8, 95% confidence interval [CI] = 0.7-0.9, P < 0.05). Detection rates of C. parvum were higher in episode-related samples in all age groups (OR = 2.8, 95% CI = 1.9-4.2, P < 0.05) and infections in boys were more frequently symptomatic than in girls. While G. lamblia does not appear to be a consistent pathogen in this population where it is hyperendemic, Cryptosporidium has been shown to be an important cause of diarrhea in young children in the community.

Adolescent↗