Protective effect of breastfeeding: an ecologic study of Haemophilus influenzae meningitis and breastfeeding in a Swedish population.
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BACKGROUND: In Orebro County, Sweden, a 2.5-fold increase in the incidence of Haemophilus influenzae (HI) meningitis was found between 1970 and 1980. In a case-control study of possible risk factors for invasive HI infection conducted in the same area, 1987-1992, breastfeeding was found to be a strong protective factor. MATERIAL AND METHODS: In order to study the relation between incidence rates of HI meningitis between 1956-1992 and breastfeeding rates in the population an ecologic study was performed. RESULTS: A strong (negative) correlation between breastfeeding and incidence of HI infection 5 to 10 years later (rho(xy) (s) approximately -0.6) was seen, whereas no relation seems to exist for the time lag 15 years and beyond. The correlation for contemporary data was intermediate. There were similar results for the breastfeeding proportions at 2, 4 as well as 6 months of age. DISCUSSION: Our ecologic data are consistent with results from our case-control study. The time-lag for the delayed effect on the population level could be estimated although sparse data make the estimates vulnerable to sampling fluctuations. Limitations with ecologic studies are discussed. CONCLUSION: There seems to be an association between high breastfeeding rate in the population and a reduced incidence of HI meningitis 5 to 10 years later. These results do have implications on strategies for breastfeeding promotion, especially in countries where Hib vaccination is too costly and not yet implemented. (+info)
Subtyping of Haemophilus influenzae strains by pulsed-field gel electrophoresis.
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A total of 200 isolates of Haemophilus influenzae were analyzed by serotyping, biotyping, and pulsed-field gel electrophoresis (PFGE). A total of 178 epidemiologically unrelated strains of H. influenzae demonstrated a variety of genome patterns by PFGE, and 165 genotypes were thus obtained in this study. PFGE typing proved to have a much stronger discriminatory power than either serotyping or biotyping. Six serotype b strains were all classified into discrete genotypes. A PFGE analysis of 18 strains obtained from the nasopharynx, blood, and cerebrospinal fluid of patients with meningitis also supported the hypothesis that invasive H. influenzae disseminates from the nasopharynx to the bloodstream and then subsequently to other body sites. PFGE typing of 10 other strains isolated from household contacts of patients with H. influenzae infection revealed that the strain that caused the H. influenzae infection often colonized the nasopharynges of household contacts. Our findings suggest that PFGE analysis is useful for the epidemiological study of H. influenzae infection, even when the invasive disease is caused by serotype b strains. (+info)
Pneumococcal and Haemophilus influenzae meningitis in a children's hospital in Ethiopia: serotypes and susceptibility patterns.
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Streptococcus pneumoniae and Haemophilus influenzae are responsible for most pyogenic meningitis cases in children in Ethiopia. Resistance of S. pneumoniae and H. influenzae to penicillin and chloramphenicol respectively has been reported globally. Resistance has been related to specific serotypes of S. pneumoniae or to beta-lactamase-producing H. influenzae strains. This study describes the serotypes/ serogroups and susceptibility pattern of the two organisms causing meningitis in Ethiopian children. There were 120 cases of meningitis caused by S. pneumoniae (46) and H. influenzae (74) over a period of 3 years (1993-95). Nineteen children died from pneumococcal and 28 from haemophilus meningitis. Penicillin-resistant pneumococcal meningitis (4/8 = 50%) caused a greater mortality rate than penicillin-susceptible pneumococcal meningitis (15/38 = 39%). Common serotypes accounting for 76% of S. pneumoniae were type 14, 19F, 20, 1, 18 and 5; and serotypes 14, 19F and 7 (accounting for 17% of strains) showed intermediate resistance to penicillin G. 97% of the H. influenzae isolates were type b, and in only two cases beta-lactamase-producing. 72% of isolates of the S. pneumoniae we identified belong to serotypes preventable by a 9-valent vaccine. Our study highlights the possibility of resistant pyogenic meningitis in children in Ethiopia due to emerging resistant strains of S. pneumoniae and H. influenzae isolates. (+info)
The pathogenic role of fimbriae of Haemophilus influenzae type b in murine bacteraemia and meningitis.
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Complement activation and development of murine bacteraemia and meningitis following intranasal instillation of cell-bound fimbriated or non-fimbriated organisms were compared to clarify the role of fimbriae in the pathogenesis of illnesses caused by Haemophilus influenza type b (Hib). In-vitro resistance of non-fimbriate bacteria to the bactericidal effects of normal human serum was at least 400 times greater than that of fimbriate bacteria. The amount of C3 bound to fimbriate Hib was more than that to non-fimbriate Hib. When mice were infected with fimbriate bacteria, 11.5% died. When mice were infected with non-fimbriate bacteria, the mean number of viable organisms gradually increased or was constant up to day 7; 38.5% of these mice died. These in-vivo results were coincident with the in-vitro data. However, the content of polyribosyl ribitol phosphate (PRP) in fimbriate organisms was the same as in non-fimbriate organisms. These results indicate that fimbriate Hib may be less likely to produce bacteraemia and meningitis, correlating with the greater susceptibility to complement-mediated bacteriolysis and the lower mortality seen with this type of organism, although fimbriae increase adherence to epithelial cells (mucosal surface). (+info)
Antimicrobial resistance patterns of Haemophilus influenzae isolated from patients with meningitis in Sao Paulo, Brazil.
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From 1989 to 1995, a total of 391 Haemophilus influenzae isolates were recovered from the cerebrospinal fluid (CSF) of hospitalized patients in Sao Paulo, Brazil. The majority of strains were isolated from infants aged less than 5 years. Strains belonging to biotype I (64.7%), biotype II (34.5%) and biotype IV (0.76%) were detected. Ninety-nine percent of these strains were serotype b. Minimal inhibitory concentration (MIC) was determined for ampicillin, chloramphenicol and ceftriaxone. The ss-lactamase assay was performed for all strains. The rate of ss-lactamase producer strains ranged from 10 to 21.4% during a period of 7 years, with an overall rate of 13.8%. Of the 391 strains analyzed, none was ss-lactamase negative ampicillin resistant (BLNAR). A total of 9.7% of strains showed resistance to both ampicillin and chloramphenicol; however, 4% of them were resistant to ampicillin only and 2% to chloramphenicol. All strains were susceptible to ceftriaxone and the MIC90 was 0.007 microg/ml, suggesting that ceftriaxone could be an option for the treatment of bacterial meningitis in pediatric patients who have not been screened for drug sensitivity. (+info)
Outcome of meningitis caused by Streptococcus pneumoniae and Haemophilus influenzae type b in children in The Gambia.
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In developing countries, endemic childhood meningitis is a severe disease caused most commonly by Streptococcus pneumoniae or Haemophilus influenzae type b (Hib). Although many studies have shown that fatality rates associated with meningitis caused by these organisms are high in developing countries, little is known about the long-term outcome of survivors. The purpose of this study was to assess the importance of disabilities following pneumococcal and Hib meningitis in The Gambia. 257 children aged 0-12 years hospitalized between 1990 and 1995 with culture-proven S. pneumoniae (n = 134) or Hib (n = 123) meningitis were included retrospectively in the study. 48% of children with pneumococcal meningitis and 27% of children with Hib meningitis died whilst in hospital. Of the 160 survivors, 89 (55%) were followed up between September 1996 and October 1997. Of the children with pneumococcal meningitis that were traced, 58% had clinical sequelae; half of them had major disabilities preventing normal adaptation to social life. 38% of survivors of Hib meningitis had clinical sequelae, a quarter of whom had major disabilities. Major handicaps found were hearing loss, mental retardation, motor abnormalities and seizures. These data show that despite treatment with effective antibiotics, pneumococcal and Hib meningitis kill many Gambian children and leave many survivors with severe sequelae. Hib vaccination is now given routinely in The Gambia; an effective pneumococcal vaccine is needed. (+info)
Hemophilus parainfluenzae meningitis.
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Although Hemophilus influenzae is a common cause of meningitis, other members of the Hemophilus genus are rarely the infecting organism. Of 56 cases of meningitis due to Hemophilus species obseved at one hospital in the period 1970-74, 53 were due to H. influenzae and 3 to H. parainfluenzae. In the cases of H. parainfluenzae meningitis the clinical picture was complicated by associated sepsis, and therapy with ampicillin was not entirely satisfactory. (+info)
An investigation of the family background of acute Haemophilus infections of children.
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Nose and throat swabs, for culture of Haemophilus influenza type b, and blood samples, for measurement of antibodies specific for that serotype, were collected from members of 28 families from which children had been admitted to hospital with acute H. influenzae type b infections (mainly meningitis or epiglottitis). The patients with meningitis were younger than those with epiglottitis and had more siblings, with a marked predominance of sisters. Investigations within a few days of admission of the affected children to hospital detected carriers of H. influenzae type b (19 altogether) in 13 of the 28 families, including 9 of the 13 families with 3 or more children. Members with raised antibody titres for H. influenzae type b (suggesting the presence of the organism for at least a few weeks) were found in 17 of the 25 families from which blood samples were obtained, including all 11 families with 3 or more children. Most of the patients probably acquired their infections from within their own families, and siblings under 11 years old were of predominant importance both as carriers and as potential sources of the patients' infections. Persistence of the organism within families for up to 6 months was demonstrated. Possible reasons for the difference in age-incidence between haemophilus meningitis and epiglottitis and for the occurrence of the former in babies with older sisters are suggested, and also a possible connection between the results of this survey and the likely value of immunization against H. influenzae type b. (+info)