ABSTRACT
A. Haemophilus spp. Pfeiffer first reported Haemophilus injIuenzae in 1892 as the primary agent of epidemic influenza. In the 1930s, based on the capsular polysaccharide composition, Pittman identified six H. injIuenzae serotypes (a to f) (1). In 1988, conjugate vaccines which prevent H. injIuenzae type b infection were first licensed; since then, most western countries have included this vaccine into their national vaccination programs with the subsequent result of a drastic reduction in the number of infections. According to the World Health Organization, however, the prevalence ofH. injluenzae type b invasive infections worldwide continues to be elevated as the vaccine has not been introduced in the majority of underdeveloped countries (2).
