Resistance patterns of Haemophilus influenzae

Haemophilus influenzae is an important respiratory tract pathogen, and the prevalence of strains resistant to the antibiotics used to treat it has inc reased since the 1970s, Data on H. influenzae have been gathered in the Ale xander Project, an ongoing, international surveillance study, They reveal t hat beta-lactamase production is the primary mechanism for H, influenzae re sistance and that the resistance has a wide geographical variation, reachin g critical levels in some countries. Unlike many techniques used in the pas t, Alexander Project methods provide accurate, reproducible susceptibility data, allowing the comparison of resistance prevalence over time and betwee n areas. Traditional antimicrobial breakpoints are being superseded by more accurate and clinically relevant methods of predicting drug efficacy, such as time above the MIG, AUC:MIC ratios and pharmacodynamic breakpoints, Con tinued surveillance for resistance and susceptibility testing of H. influen zae is vital to maximize the benefits of antimicrobial therapy and to conta in the spread of infection.