Haemophilus influenzae type B (HiB)
Fact sheet N°294
December 2005
Haemophilus influenzae type b, or Hib, is a bacterium
estimated to be responsible for some three million serious illnesses and
an estimated 386 000 deaths per year, chiefly through meningitis and
pneumonia. Almost all victims are children under the age of five, with
those between four and 18 months of age especially vulnerable.
In developing countries, where the vast majority of Hib deaths
occur, pneumonia accounts for a larger number of deaths than
meningitis. However, Hib meningitis is also a serious problem in such
countries with mortality rates several times higher than seen in
developed countries; it leaves 15 to 35% of survivors with permanent
disabilities such as mental retardation or deafness. Contrary to what
the name Haemophilus influenzae suggests, the bacterium does not cause
influenza.
