Population-based study of non-typable Haemophilus influenzae invasive disease in children and neonates

Lancet. 1993 Apr 3;341(8849):851-4. doi: 10.1016/0140-6736(93)93059-a.


The extent of non-capsulate, non-serotypable Haemophilus influenzae (NST) as a cause of serious invasive disease in children has not been fully defined. We describe the epidemiology of these childhood infections from cases identified during a continuing prospective survey of invasive H influenzae disease in the Oxford region, UK. 408 strains of H influenzae were isolated from cases of invasive disease. 383 (94%) were H influenzae type b (Hib), 24 (6%) were NST strains, and 1 was a type f strain. 3 of the NST strains were non-capsulate type b mutants (b-), but the remaining 21 strains were from the phylogenetically distinct and heterogeneous population of non-capsulate H influenzae (NC). 10 of the NC strains were isolated from neonates with sepsis; crude mortality rate was 40%, with an incidence of 4.6 cases per 100,000 livebirths. 11 NC strains were isolated from children after the neonatal period and under 10 years of age, 4 (36%) of which had severe, unrelated, predisposing conditions. The incidence of NC invasive diseases in these children was 0.5 per 100,000 per year. The attributable mortality for these infections was 10%. Infections due to these H influenzae strains are, after the implementation of Hib vaccines, likely to persist and represent a substantial proportion of the serious infections caused by this species.

MeSH terms

  • Blotting, Southern
  • Child
  • Child, Preschool
  • England / epidemiology
  • Haemophilus Infections / epidemiology*
  • Haemophilus Infections / microbiology
  • Haemophilus influenzae* / classification
  • Haemophilus influenzae* / genetics
  • Haemophilus influenzae* / isolation & purification
  • Humans
  • Infant
  • Infant, Newborn
  • Prospective Studies
  • Serotyping