Increasing Incidence of Invasive Haemophilus Influenzae Disease in Adults, Utah, USA

Emerg Infect Dis. 2011 Sep;17(9):1645-50. doi: 10.3201/eid1709.101991.

Abstract

Since the introduction of the Haemophilus influenzae type b vaccine, the incidence of invasive H. influenzae type b disease among children has fallen dramatically, but the effect on invasive H. influenzae disease among adults may be more complex. In this population-based study we examined the epidemiology and outcomes of invasive disease caused by typeable and nontypeable H. influenzae among Utah adults during 1998-2008. The overall incidence increased over the study period from 0.14/100,000 person-years in 1998 to 1.61/100,000 person-years in 2008. The average incidence in persons >65 years old was 2.74/100,000 person-years, accounting for 51% of cases and 67% of deaths. The incidence was highest for nontypeable H. influenzae (0.23/100,000 person-years), followed by H. influenzae type f (0.14/100,000 person-years). The case-fatality rate was 22%. The incidence of invasive H. influenzae in Utah adults appears to be increasing. Invasive H. influenzae infection disproportionately affected the elderly and was associated with a high mortality rate.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Bacteremia / epidemiology*
  • Bacteremia / microbiology
  • Bacteremia / mortality
  • Haemophilus Infections / epidemiology*
  • Haemophilus Infections / microbiology
  • Haemophilus Infections / mortality
  • Haemophilus influenzae / classification
  • Haemophilus influenzae / pathogenicity*
  • Humans
  • Incidence
  • Meningitis, Haemophilus / epidemiology
  • Meningitis, Haemophilus / microbiology
  • Meningitis, Haemophilus / mortality
  • Middle Aged
  • Serotyping
  • Utah / epidemiology
  • Young Adult