Antimicrobial resistance in Haemophilus influenzae: how can we prevent the inevitable? Commentary on antimicrobial resistance in H. influenzae based on data from the TARGETed surveillance program.

Haemophilus influenzae is an important cause of respiratory tract infections, particularly in elderly persons. It is the major bacterial pathogen in acute exacerbations of chronic bronchitis (AECB) and also causes otitis media and sinusitis. In many cases, treatment is empiric, and there is a lack of understanding of resistance issues with this bacterium. There is little understanding of the epidemiology of H. influenzae respiratory infections, although some strains may be replaced by new strains that cause more severe infections. There is almost no information on how these bacteria may spread in the community. Ampicillin resistance is significant (it may be >30%), and there are few oral agents capable of reducing organism burden. There is little understanding of the epidemiology of H. influenzae respiratory infections, and almost no information on how these bacteria may spread in the community. Recent evidence suggests that these bacteria may behave in a similar way to Streptococcus pneumoniae. If that proves correct, then it will be important to follow these organisms in the community to determine if resistance determinants may spread more widely than we have thus far believed. The implications for treatment, infection prevention and control, and public health should not be underestimated as it has been with other organisms such as S. pneumoniae and Staphylococcus aureus.