Molecular epidemiology and evolution of Haemophilus influenzae

Haemophilus influenzae remains a common cause of illness in children worldwide. H. influenzae type b is the leading cause of bacterial meningitis in children before introduction of vaccination and is a common cause of pneumonia, epiglottis and septic arthritis. Since the implementation of the Hib conjugate vaccine, the non-typeable H. influenzae has rapidly decreased in respiratory and invasive infections in children and adults. However, the rate of antibiotic resistance of H. influenzae varies with region and period and is usually on the rise. In this review, typing of H. influenzae, virulence factors and resistance will be dissertated.