Search PubMed⌕ Search

Biomedical subjects

R Dagan

Publications and source records attributed to R Dagan.

At least 127 records · Page 7Linked to original sources
PubMed1996

Measles immunity and response to revaccination of a young adult population in Israel.

In order to evaluate the true immune status and the effect of revaccination on a young adult population, we collected serum samples from 289 military recruits who were vaccinated during an outbreak in 1991. Most vaccinees, age 18-25 years, had apparently been immunized once before as infants. Sera collected just prior to the vaccination and 14 and 28 days afterwards were tested for measles antibodies by hemagglutination inhibition (HI) and enzyme-linked immunosorbent assay (ELISA)-IgM. Before vaccination, 46 (15.9%) of the subjects had no HI antibodies, (< 1:4) and 48 (16.6%) had borderline (1:4) HI titer. Following vaccination, only ten (3.5%) remained negative and 19 (6.6%) had borderline titer. The increase in HI antibody titer was inversely proportional to the prevaccination titer, and 159 subjects (55.0%) showed no increase at all. The geometric mean titer (GMT) rose from 9.14 to 21.47. Among the prevaccination-negative subjects (HI < 1:4) 28 (60.9%) reached a postvaccination titer of > or = 1:8, and eight (17.4%) reached a titer of 1:4. Twelve (26.1%) of the negative subjects seroconverted and developed IgM, 16 (35%) seroconverted without IgM, and 18 (39%) remained negative and did not develop IgM. A group of eight vaccinees with prevaccination titer of > or = 1:4 developed IgM. Some were probably infected by the circulating wild-type virus prior to the vaccination. Thus, a total number of 20 of the 289 subjects studied (6.9%) had true negative preimmune status as judged by the IgM test. However, the vaccination campaign prevented further measles cases, apparently by increasing the population's immunity, particularly in individuals with very low titers or without measles antibodies.

Adolescent↗
PubMed1996

Audiometric findings in children with chronic suppurative otitis media without cholesteatoma.

Chronic suppurative otitis media without cholesteatoma (CSOMWC) is usually associated with an increase in air conduction thresholds. However, only a few investigations reported on loss of cochlear function in the pediatric population. We undertook a prospective study in order to further delineate air and bone conduction levels in children with CSOMWC and the possible relationship between sensorineural hearing loss (SNHL) and other clinical characteristics that might reflect the extent of disease. Eighty-seven children were enrolled, 40 of which had bilateral disease. Hence, the total number of diseased ears tested was 127. Audiometric studies were performed three days after achieving a 'dry' ear following medical treatment. We found no statistically significant differences between the bone conduction threshold tested in ears with CSOMWC and control ears. This was also the case in 47 children with unilateral disease when cochlear function was investigated in the diseased and uninvolved ear in the same patient. Clinical correlation showed no association between age, sex, duration of otorrhea and presence of granulation or polyps and the degree of cochlear loss. Our study shows that CSOMWC in children has little effect on cochlear function.

Adolescent↗
PubMed1996

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

We tested the safety and immunogenicity of the new recombinant hepatitis B virus (HBV) vaccine produced via expression of the Pre-S1, Pre-S2 and S protein components of the hepatitis B surface antigen (HBsAg). A reduced dose (2.5 micrograms) of the vaccine (Bio-Hep-B) was tested in children aged 4-9 years and was compared to a 10 microgram dose of a licensed vaccine (Engerix-B) in a randomized manner. Both vaccines were administered in 3 doses (0, 1 and 6 month intervals). Adverse events were collected 5 days following each vaccination by a diary card provided to the parents. Immunogenicity was tested by measuring anti-hepatitis B surface antibody (anti-HBs). A total of 217 children were enrolled (162 in the Bio-Hep-B group and 55 in the Engerix-B group). Total adverse events were observed in 35% of the Bio-Hep-B group and 33% of the Engerix-B group, with no differences when each of the potential adverse events was considered. Titers were within the expected range (geometric mean titers post dose 1, 2 and 3 were 45.8, 8360.2 and 1445.7, respectively, for Bio-Hep-B and 36.3, 10316.1 and 1898.7, respectively, for Engerix-B). A trend toward better immunogenicity with Bio-Hep-B was observed at early visits when measured by both seroconversion (anti-HBs > or = 2.1 mIU ml-1) rate and seroprotection (anti-HBs > or = 10 mIU ml-1) rate; however, statistical significance was not reached. We conclude that in children, Bio-Hep-B vaccine at a reduced dose was as safe and as immunogenic as Engerix-B given at the regular pediatric dosage.

Child↗
PubMed1996

Full-thickness foot burn of a pilgrim to Mecca.

This report relates to burns of the feet suffered by a pilgrim to Mecca who walked barefoot in the hot desert sun. He subsequently presented with full-thickness burn injuries to the soles of his feet. When the patient developed acute coronary insufficiency, immediate surgery could not be performed. He was therefore treated conservatively with salicylic acid and Silverol cream. Spontaneous closure of the wounds was achieved in the course of 2 months.

Acute Disease↗
PubMed1996

Subclasses of IgA antibodies in serum and saliva samples of newborns and infants immunized against rotavirus.

Little is known about subclass levels of IgA in serum or saliva of infants in the perinatal period. We have previously shown that very young infants are capable of responding to an experimental rotavirus vaccine with both serum and salivary IgA, and that small amounts of IgA are already detectable in cord blood of these infants. In the present study, total IgA1 and IgA2 antibodies in serum and saliva samples of some of these infants at birth, at 6 weeks of age, and at 12 weeks of age, were determined by a quantitative ELISA. Also, subclass-specific IgA antibodies to the rotavirus group A common antigen were determined by ELISA. The ratio of average serum concentrations of IgA1 to IgA2 for 14 infants at 6 weeks of age was 19:1, while in saliva it was 5:1. Between 6 and 12 weeks of age levels of serum IgA1 increased by 25%, while levels of IgA2 did not increase perceptibly. Concentrations of IgA1 were higher in infant sera than in saliva, while concentrations of IgA2 were slightly higher in saliva than in serum. When calculated as specific ELISA units per mg IgA1, more salivary IgA1 was specific for rotavirus than serum IgA1. Further studies are needed to determine when infant IgA2 levels rise to values more characteristic of children and adults. This may be of significance for infant mucosal immunizations if secretory IgA2, more resistant to bacterial proteases than IgA1, is required for efficient defence of the respiratory and intestinal tracts.

Antibodies, Viral↗
PubMed1996

Serogroup-specific epidemiology of Streptococcus pneumoniae: associations with age, sex, and geography in 7,000 episodes of invasive disease.

A study sample of 7,010 episodes of invasive Streptococcus pneumoniae disease was obtained by combining 13 existing datasets. Disease episodes due to each of 12 pneumococcal serogroups (1, 3-9, 14, 18, 19, and 23) were then compared with episodes in a constant internal control group to describe serogroup-specific variations in disease frequency by age, sex, and geographic origin. The results are presented as odds ratios (with 95% confidence intervals) derived by logistic regression, with adjustment for the major confounders, including dataset of origin. Variation in the male:female ratios between serogroups is small, suggesting that capsular characteristics are an unlikely explanation for the male preference of S. pneumoniae. Serogroups associated with higher nasopharyngeal prevalence (e.g., 19 and 24) are relatively more common in Europe and North American, while the invasive serotypes 1 and 5 are much more common in South America. The custom of reporting serogroup frequencies in two age groups, children and adults, conceals much of the variation in the age distributions across the whole span of life. The reduction of risk associated with serogroups 6, 14, 18, 19, and 23 beyond childhood follows different gradients, being most abrupt in serogroups 14 and most gradual in serogroup 18. The relative risk of disease with serotype 1 declines steadily throughout life, while with serotypes 3 and 8 it increases over middle age. Serogroups 7 and 23 are found unusually frequently in the third decade of life. Because of the wide differences in the epidemiology of individual serogroups of S. pneumoniae, it is questionable whether pneumococcal infection should continue to be classified as a single disease entity.

Adolescent↗
PubMed1996

Reduction of nasopharyngeal carriage of pneumococci during the second year of life by a heptavalent conjugate pneumococcal vaccine.

Children 12-18 months old were randomized to receive one dose of a conjugate heptavalent pneumococcal vaccine, two doses of the same vaccine, or one dose of a 23-valent native polysaccharide vaccine. Before immunization, pneumococci included in the conjugate vaccine were isolated from 24% of the children, and an antibiotic-resistant pneumococcus was isolated from 22% of the children. The vaccines had no effect on carriage of non-vaccine-type pneumococci. In contrast, there was a significant reduction in carriage of vaccine-type pneumococci 3 months after one dose and 1 month after a second dose of conjugate vaccine (from 25% to 9% and 7%, respectively; P < .001). No effect was seen after vaccination with the nonconjugate vaccine. One year after immunization, carriage of antibiotic-resistant vaccine-type pneumococci in children receiving conjugate vaccine was lower than that in children receiving the nonconjugate vaccine (4% vs. 14%, P = .042). Conjugate pneumococcal vaccines may reduce spread of pneumococci in the community.

Antibodies, Bacterial↗
PubMed1996

Nasopharyngeal colonization in southern Israel with antibiotic-resistant pneumococci during the first 2 years of life: relation to serotypes likely to be included in pneumococcal conjugate vaccines.

Nasopharyngeal carriage of Streptococcus pneumoniae was studied in 162 healthy infants at ages 2, 4, 6, 7, 12, and 13 months and in an additional 352 healthy children at ages 12, 15, 18, 21, and 24 months. Carriage was 26%, 39%, and 62% at 2, 12, and 24 months, respectively, and the respective resistance to > or = 1 antibiotic was 11%, 19%, and 27%. The presence of an older sibling or antibiotic treatment during the month preceding the culture was associated with carriage of resistant pneumococci in infants, whereas attendance at large day care centers was associated with carriage during the second year of life. Antibiotic resistance was detected in all 7 serotypes included in the candidate pediatric conjugate vaccines and was significantly more prevalent among vaccine-type pneumococci than among non-vaccine-type pneumococci. The use of conjugate vaccines may reduce the spread of resistant pneumococci.

Anti-Bacterial Agents↗
PubMed1996

Impaired bacteriologic response to oral cephalosporins in acute otitis media caused by pneumococci with intermediate resistance to penicillin.

BACKGROUND: Penicillin resistance of Streptococcus pneumoniae, one of the most common causes of acute otitis media, has recently increased and is now highly prevalent in many regions. However, its contribution to clinical failure still must be proved. Because the role of antibiotics in acute otitis media is to eradicate the pathogens present in the middle ear fluid, we conducted a randomized controlled study to determine bacterial eradication of pathogens in acute otitis media by two commonly used oral cephalosporins, cefuroxime axetil (30 mg/kg/day) and cefaclor (40 mg/kg/day). METHODS: Patients 6 to 36 months old with pneumococcal otitis media seen in the Pediatrics Emergency Room were studied. An initial middle ear fluid culture was obtained at enrollment, and a second culture was obtained on Day 4 or 5 during treatment. Follow-up was done also on Days 10, 17 and 42 after initiation of treatment. In cases of clinical relapse a third culture was obtained. RESULTS: In total 78 patients were enrolled, 41 in the cefuroxime axetil group and 37 in the cefaclor group. Of the 78 S. pneumoniae isolates 31 (40%) were intermediately penicillin-resistant (MIC 0.125 to 1.0 microgram/ml). Of the 47 patients with penicillin-susceptible organisms 3 (6%) had bacteriologic failure vs. 4 of 19 (21%) and 7 of 11 (64%) of those with MIC of 0.125 to 0.25 microgram/ml and 0.38 to 1.0 microgram/ml, respectively (P < 0.001). For intermediately resistant pneumococci, in 7 of 12 (58%) of those receiving cefaclor the isolate was not eradicated vs. only 4 of 19 (21%) of those receiving cefuroxime axetil (P = 0.084). MIC to the administered cephalosporin of > 0.5 microgram/ml was associated with bacteriologic failure. Clinical failure was observed in 9 of 14 (64%) patients with bacteriologic failure vs. 10 of 52 (19%) patients with bacteriologic eradication (P = 0.003). CONCLUSION: Intermediately penicillin-resistant S. pneumoniae is associated with an impaired bacteriologic and clinical response of acute otitis media to cefaclor and cefuroxime axetil. This effect was more pronounced with cefaclor than with cefuroxime axetil.

Acute Disease↗
PubMed1995

[Penicillin resistance of pneumococci from invasive pediatric infections].

Susceptibility to antibiotics of 199 isolates of Streptococcus pneumoniae from blood and cerebrospinal fluid of children hospitalized during 1987-1993 was tested. Of 119 isolates, 18% were resistant to penicillin. The prevalence in 1992-93 was double that in 1987-89. The increase in minimal inhibitory concentrations (MIC) of penicillin was associated with an increase in MIC of other beta-lactams. There was also resistance to other antibiotics: trimethoprim-sulfamethoxazole, erythromycin and chloramphenicol. Most of the resistant isolates belonged to serogroups 6, 14, 19 and 23. When planning vaccine policies, resistant types should be taken into consideration.

Drug Resistance, Microbial↗
PubMed1995

Epidemiology, etiology, and clinical features of septic arthritis in children younger than 24 months.

OBJECTIVE: To examine the incidence, etiology, and clinical features of septic arthritis in patients younger than 24 months. DESIGN: Retrospective, 1988 through 1993 period, chart review-based survey. PATIENTS: All children with bacteriologically proved septic arthritis that was diagnosed at a medical center serving southern Israel (population 320,000). Septic arthritis was defined by clinical evidence of joint inflammation and a positive synovial fluid or blood culture, antigen detection test, or a standard tube agglutination titer of 160 or greater for Brucella species. INTERVENTIONS: None. RESULTS: During the 6-year period, 40 children had septic arthritis diagnosed. Twenty-six (65%) were male. The annual incidence of septic arthritis was 37.1 per 100,000. The two most common organisms isolated were Kingella kingae in 19 (48%) and Haemophilus influenzae type b in eight (20%). The clinical presentation was frequently mild: a body temperature of less than 38.3 degrees C was recorded in 14 (35%) of 40 children, leukocyte count of less than 15 x 10(9)/L in 13 (34%) of 38, and erythrocyte sedimentation rate of less than 30 mm per hour in four (11%) of 35. In eight (36%) of 22 patients, less than 50 x 10(9)/L leukocytes were counted in the synovial fluid. CONCLUSIONS: The diagnosis of septic arthritis in young children requires a high index of suspicion, and the disease cannot be excluded on the basis of lack of fever or normal results of laboratory tests. Kingella kingae appears to be the most common cause of septic arthritis in patients younger than 24 months, although confirmatory studies from other geographic areas are still needed.

Arthritis, Infectious↗
PubMed1995

Severe complications of measles requiring intensive care in infants and young children.

OBJECTIVE: To evaluate the characteristics of severe complications of measles in patients admitted to a pediatric intensive care unit. DESIGN: Clinical description of a case series. SETTING: The Pediatric Intensive Care Unit of Soroka Medical Center, Beer-Sheva, Israel, during a measles epidemic. PATIENTS: Fifteen pediatric patients with measles requiring intensive care. RESULTS: Fifteen of 237 hospitalized children with measles required intensive care in the Pediatric Intensive Care Unit. Eleven patients were malnourished; none had been vaccinated for measles. All 15 patients required mechanical ventilation for pneumonia that had caused severe respiratory distress. Twelve of 15 patients were severely hypoxemic before intubation. Seven had a clinical syndrome consistent with adult respiratory distress syndrome. Other complications on admission to the intensive care unit included spontaneous pneumothorax in three patients, empyema in two, encephalopathy in seven, shock in three, sepsis in five, hypocalcemia in 11, thrombocytopenia in eight, and coagulopathy in seven. Complications during treatment included pneumothorax in four patients, fibrosing alveolitis in one, brain infarct in one, thrombus formation in three, and nosocomial sepsis in one. Four patients had long-term sequelae (chronic lung disease, subacute sclerosing panencephalitis, hemiplegia, and partial amputation of a limb), and seven patients recovered uneventfully. Four patients died; all had adult respiratory distress syndrome, three had pneumothorax, and one had nosocomial sepsis. CONCLUSIONS: Patients with measles who require intensive care have a high risk for death or long-term complications, even when treated in a modern pediatric intensive care unit. Adult respiratory distress syndrome and air leaks were the most severe complications in these patients. To reduce the severity of these complications, mechanical ventilation should be based on using the lowest possible inspiratory pressure and fraction of inspired oxygen, while accepting an arterial oxygen pressure less than 60 mm Hg. Secondary bacteremia was an early and prominent complication, and antibiotic treatment should be instituted early in patients with measles requiring intensive care.

Bacteremia↗
PubMed1995

Carriage of Streptococcus pyogenes among infants and toddlers attending day-care facilities in closed communities in southern Israel.

Infants and toddlers attending ten day-care facilities in closed communities in southern Israel were tested monthly for pharyngeal carriage of Streptococcus pyogenes and associated respiratory morbidity. Overall, the prevalence of Streptococcus pyogenes was 2.7% in infants and 8.4% in toddlers, reaching 8.5% and 17.8% in the two groups, respectively by midwinter. In 4 of 61 (6.6%) infants and 15 of 67 (22.4%) toddlers, the organism was recovered in more than one month (range 2 to 5 months). Streptococcus pyogenes in the pharynx was only associated with rhinitis during the spring and summer but not with other respiratory symptoms. During the study period, a mean of 0.9 strains were isolated in day-care facilities attended by infants, while a mean of 2.1 strains were found in toddlers. Young children attending day-care facilities show early acquisition of Streptococcus pyogenes in the pharynx.

Carrier State↗
PubMed1995

How far can the paediatric patient with a serious infection be managed as an outpatient?

Serious infections are often treated by paediatricians with parenteral antibiotics. Traditionally, patients receiving parenteral treatment are hospitalized. However, hospitalization has a grave negative impact on the child. The present article discusses the potential benefits of outpatient treatment of serious paediatric infections, together with the logistic approach for such treatment. Outpatient treatment for serious paediatric infections may provide an excellent medical treatment that both reduces costs and increases the patient's quality of life.

Ambulatory Care↗