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The emergence of Haemophilus influenzae types e and f as significant pathogens

L A Waggoner-Fountain1, J O Hendley, E J Cody

  • 1Department of Pediatrics, University of Virginia Health Sciences Center, Charlottesville 22908, USA.

Clinical Infectious Diseases : an Official Publication of the Infectious Diseases Society of America
|November 1, 1995
PubMed

Insights

Non-type b encapsulated Haemophilus influenzae meningitis is increasing, with types e and f identified in four children. This rise may be linked to the success of Haemophilus influenzae type b vaccination programs.

Area of Science:

  • Pediatric Infectious Diseases
  • Bacteriology
  • Vaccinology

Background:

  • Haemophilus influenzae type b (Hib) was historically the leading cause of bacterial meningitis in children.
  • Hib vaccines have dramatically reduced invasive Hib disease and carriage.
  • Other encapsulated serotypes of H. influenzae rarely caused invasive infections.

Observation:

  • Four cases of non-type b encapsulated Haemophilus influenzae meningitis (two type e, two type f) occurred within six months.
  • These cases were diagnosed in children at the University of Virginia.
  • Clinical presentation and treatment for non-type b meningitis mirror that of Hib meningitis.

Findings:

  • An apparent increase in invasive disease caused by non-type b encapsulated H. influenzae serotypes.
  • The observed rise in non-type b infections is potentially a consequence of reduced Hib prevalence.
  • Reduced oropharyngeal carriage of Hib may allow other serotypes to emerge.

Implications:

  • Highlights the need for continued surveillance of all encapsulated H. influenzae serotypes.
  • Suggests potential shifts in the epidemiology of bacterial meningitis post-Hib vaccination.
  • Underscores the importance of understanding the impact of vaccination on the carriage and disease spectrum of related pathogens.

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