Invasive Haemophilus influenzae Disease: A Population-Based Evaluation of the Role of Capsular Polysaccharide Serotype

Wenger, Jay D.; Pierce, Richard L.; Deaver, Katherine; Franklin, Ruth; Bosley, G S; Pigott, Nan E.; Broome, Claire V.

doi:10.1093/infdis/165-supplement_1-s34

Cited by 60 publications

(47 citation statements)

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“…14 In another population-based study in 1986, 1324 of 1872 isolates (71%) from invasive disease were type b; 14 of 1872 (0.7%) were type a. 6 Invasive disease caused by nonserotype b encapsulated organisms occurred almost exclusively in persons older than 5 years. Thus, the clustering of 4 cases of invasive disease and 1 of pneumonia caused by H influenzae serotype a during a 10-month period is unexpected on the basis of active and passive surveillance from a variety of sites.…”

Section: Discussionmentioning

confidence: 99%

“…4,5 However, surveillance in the United States, Great Britain, and Switzerland until now has not shown significant increases in infections of children with other serotypes. [5][6][7] We describe 5 cases of invasive disease, including 4 cases of meningitis in young children attributable to H influenzae serotype a in Utah during a 10-month period. Three cases were attributable to a unique strain that possesses a deletion mutation associated with invasive strains of Hib but not normally found in noninvasive strains.…”

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confidence: 99%

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Invasive Serotype a Haemophilus influenzaeInfections With a Virulence Genotype Resembling Haemophilus influenzae Type b: Emerging Pathogen in the Vaccine Era?

et al. 2001

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ABSTRACT. Objective. Haemophilus influenzae type b causes severe disease in nonimmune infants and young children; other serotypes are uncommon pathogens and thought to have low virulence. Some have hypothesized that with the virtual elimination of H influenzae type b, other serotypes might acquire virulence traits and emerge as important pathogens of children. We describe the clinical, epidemiologic, and molecular biologic features of 5 cases of severe disease attributable to Haemophilus influenzae type a.Methods. After observing 4 cases of invasive disease caused by H influenzae type a, we reviewed microbiology records at 3 reference laboratories that perform all serotyping in Utah and surveillance databases. Strains of H influenzae type a and control strains were examined by Southern blotting with the use of the cap probe pUO38 and by pulsed-field gel electrophoresis. The putative virulence mutation, the IS1016-bexA deletion, was detected by polymerase chain reaction amplification and sequencing.Results. During a 10-month period, we observed 5 children with severe invasive disease caused by H influenzae type a. No isolates of H influenzae type a had been submitted to the reference laboratories between 1992 and 1998. The median age of patients was 12 months (range: 6 -48 months). Four of 5 had meningitis and bacteremia; 1 had purpura fulminans. Three isolates, representing 1 of 2 pulsed-field gel electrophoresis patterns, contained the IS1016-bexA deletion and were associated with particularly severe disease.Conclusions. We describe an unusual cluster of severe disease caused by H influenzae type a that resembles the clinical and epidemiologic features of H influenzae type b disease. Our data support the hypothesis that the IS1016-bexA deletion may identify more virulent strains of H influenzae. Pediatrics 2001;108(1). URL: http://www. pediatrics.org/cgi/content/full/108/1/e18; Haemophilus influenzae, epidemiology, virulence, serotyping, pathogenicity.

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Section: Discussionmentioning

confidence: 99%

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confidence: 99%

Invasive Serotype a Haemophilus influenzaeInfections With a Virulence Genotype Resembling Haemophilus influenzae Type b: Emerging Pathogen in the Vaccine Era?

et al. 2001

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“…Such disease has been primarily associated with H. influenzae localized in respiratory infections, mostly in children above the age of 5 years and adults (16,29). The reemergence of Hib in vaccinated children has also been reported (15).…”

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confidence: 99%

“…influenzae can express six capsule polysaccharides (serotypes a to f), of which serotype b was responsible for the major burden of H. influenzae invasive disease before the Hib vaccination era (19,20,28,29,30). The method most widely used for identifying the capsule serotype of H. influenzae is slide agglutination (SlAg) with polyclonal sera.…”

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Evaluation of Methodology for Serotyping Invasive and Nasopharyngeal Isolates of Haemophilus influenzae in the Ongoing Surveillance in Brazil

et al. 2003

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To assess the magnitude of discrepant results obtained by routine Haemophilus influenzae serotyping, 258 isolates, collected by the epidemiological surveillance system in Brazil from individuals with invasive diseases or carriage, were evaluated by two slide agglutination (SlAg) methods: SlAg method 1, by which strains were initially screened with a serotype b-specific antiserum, and SlAg method 2, by which strains were tested against all serotype-specific antisera in parallel. Investigators comparing results of the two SlAg methods with those obtained by capsule type-specific PCR were blinded to the method used. The serotype prevalence rates found by the three methods were significantly different, involving discrepancies mainly between serotype b and noncapsulated (NC) isolates. For invasive isolates (n ‫؍‬ 131), the overall agreement rate between SlAg method 1 or 2 and PCR was 68.0 or 88.3%, respectively, whereas for colonizing isolates (n ‫؍‬ 127) the corresponding rate was 46.5 or 94.2%, respectively. SlAg method 2 improved the ascertainment of serotypes over that obtained with SlAg method 1, demonstrating good correlation with PCR. Use of the polyvalent antiserum as a screening reagent for SlAg for invasive and colonizing isolates showed poor discriminatory power, with a sensitivity of 65.8% and a specificity of 91.7%. We stress the importance of using a well-standardized SlAg methodology and suggest that reference laboratories should utilize PCR routinely to confirm SlAg results and to check all nonspecific SlAg reactions and apparent NC isolates by SlAg in order to provide reliable data on the prevalence of H. influenzae serotypes in the H. influenzae type b vaccine era.

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“…or pleura) in children ^ years of age may be nontypeable by standard serologic tests [22]. Data from the United Kingdom, including capsular genotyping, corroborated these prevalence figures, including 7 cases of bacteremic nontypeable H. influenzae infection in previously healthy children outside the neonatal period [23].…”

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confidence: 81%

A Virulent Non-Encapsulated Haemophilus Influenzae.

&NA;

1996

The Pediatric Infectious Disease Journal

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. The specific microbial virulence factors that allow nonencapsulated H influenzae to cause serious disease remain unknown, and to our knowledge, the ability of such organisms to cause invasive disease in an animal model has never before been demonstrated. Case HistoryA 30-month-old white boy was in his usual state of good health until 6 days before admission, when he developed a low-grade fever and abdominal pain. He was seen by his primary pediatrician, who noted right otitis media and prescribed amoxicillin, which was not taken because of vomiting. Three days before admission, he was seen in an emergency department, where he appeared lethargic and dehydrated with unresolved otitis media. There were no meningeal signs on examination. His peripheral leukocyte count was 21,000/mm3 with 580Zo neutrophils and 180Zo band forms. A blood sample was obtained for culture, the patient received intravenous rehydration and 50 mg/kg ceftriaxone intravenously, and was discharged home to resume amoxicillin administration.The child continued to be irritable and listless with fever to 39.20C over the ensuing 48-72 h but was able to take liquids and amoxicillin. He was carefully examined daily by his pediatrician who, on day 6 of symptoms, noted the development of passive

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Invasive Haemophilus influenzae Disease: A Population-Based Evaluation of the Role of Capsular Polysaccharide Serotype

Cited by 60 publications

References 3 publications

Invasive Serotype a Haemophilus influenzaeInfections With a Virulence Genotype Resembling Haemophilus influenzae Type b: Emerging Pathogen in the Vaccine Era?

Invasive Serotype a Haemophilus influenzaeInfections With a Virulence Genotype Resembling Haemophilus influenzae Type b: Emerging Pathogen in the Vaccine Era?

Evaluation of Methodology for Serotyping Invasive and Nasopharyngeal Isolates of Haemophilus influenzae in the Ongoing Surveillance in Brazil

A Virulent Non-Encapsulated Haemophilus Influenzae.

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