Recurrent acute otitis media - aetiology, diagnostics and prevention

Abstract: Acute otitis media (AOM) is the most common bacterial infection in children. The clinical course varies from spontaneous recovery to life-threatening complications, and this variability mainly depends on the causative pathogen. Bacteria usually invade the middle ear from the nasopharynx, where they are carried frequently, both during sickness and health. The most common bacterium to cause AOM, and also one of the most virulent, is S. pneumoniae. Prediction of the causative pathogen can support the decision of whether or not to prescribe antibiotics for AOM. The rapid pneumococcal urine test Binax NOW was tried on nasopharyngeal and middle ear secretions and was found to have a high sensitivity and specificity for detecting pneumococci in these fluids. About 10% of children suffer from recurrent AOM (rAOM). During the last decade, childhood vaccines against S. pneumoniae have been introduced. Vaccination causes a modest reduction of AOM episodes. Whether children with rAOM benefit more than others from vaccination was investigated in a study on young children with an early AOM onset. Vaccination caused a 26% reduction in AOM episodes among children with rAOM. Knowledge of nasopharyngeal carriage patterns in rAOM children might help in developing new preventive strategies. Children in the vaccine study were rapidly colonized with otitis pathogens. H. influenzae was difficult to eradicate for these children, and was frequently carried during both sickness and health. Although hereditary factors are known to be important, it is still unclear why some children contract rAOM. We found that deficiencies of the immunological markers IgG2, MBL and C1q were frequent among rAOM children.