Activity of the French Haemophilus influenzae National Reference Center, years 1994-1995; Outset of the post-vaccinal era

During the two year period, 1994 and 1995, an important decrease of type b isolates and of meningitis occurence was observed. Strains isolated from meningitis were non-typable in 30 and 47 % of the cases. Greater incidence of meningitis occured in children between 3 and 5 years of age. This dramatic change could be due to the impact of H. influenzae type b vaccines on the epidemiology of H. influenzae type b meningitis. In the same period and for all the strains, beta-lactamase production did not vary and concerned 27 % of the strains. Beta-lactamase production concerned 33 % of the strains isolated from otitis media. Ampicillin resistance without beta-lactamase production was detected in 1.1 % of the strains studied in 1995 (non capsulated strains). Resistance to tetracyclin (8 %), chloramphenicol (2 %), and cotrimoxazole (10 %) was lower than in previous surveys.