Acute otitis media (AOM)

The most commonly isolated bacterial pathogens, in decreasing order of frequency, are Streptococcus pneumoniae, non-typable Haemophilus influenzae, Moraxella (Branhamella) catarrhalis and Streptococcus pyogenes. '0 The role of Moraxella (Branhamella) catarrhalis as a middle ear pathogen has been increasingly recognised; it is more common in the winter months. Viral infections have been implicated as a possible initiating factor, with viruses being isolated in up to 25% of middle ear aspirates. "" The epidemiology of AOM is consistent with that of a primary viral infection with secondary opportunistic bacterial infection in most cases. Implicated viruses include respiratory syncytial virus, rhinoviruses and enteroviruses.