[Epidemiologic profile of Haemophilus influenzae infection in Tunisia]

Haemophilus influenzae, a commensal bacteria, is frequently incriminated in broncho--pulmonary surinfections and severe diseases as meningitis, pneumonia and septic arthritis, particularly in young children. A multicenter study was conducted to establish the epidemiological profile of Haemophilus influenzae diseases, to determine the rate of antibiotics resistance for guide therapeutic and preventive strategies. The identification was based on the requirements for X and V factors, and the serotype b determined by agglutination. The betalactamase production was done by nitrocefin test. Antimicrobial susceptibility testing was determined on Muller Hinton chocolate agar with isovitalex. During the two year period, (January 1998 December 1999), 192 isolates of H. Influenzae were collected, 61% were recovered from invasive infections (44 meningitis, 8 bacteremia, 2 arthritis). The serotype b was identified in 55.7% of cases, 67.3% were invasive strains. 24.5% of isolates were producing betalactamase particularly invasive serotype b strains. All isolates of H. influenzae were susceptible to cefotaxim and to ofloxacin. Resistance rates to other antibiotics were: erythromycin 56.2%, tetracyclin 10.3%, rifampin 12%, chloramphénicol 1%, cotrimoxazole 16.5%, 11.5% amikacin and 20% gentamicin. The incidence of meningitis remained frequent in our country, involving the introduction of the vaccination in official calendar. Nevertheless, the surveillance of H. influenzae invasives infections and the serotyping of isolates were necessary to evaluate the impact of the immunization.