1017 SULFA-TRIMETHOPRIM PROPHLAXIS AND THE NATURAL HISTORY OF RECURRENT OTITIS MEDIA

Abstract

In a double-blind placebo-controlled study of prevention of acute otitis media (OM) in 50 children, those taking sulfamethoxazole-trimethoprim (SXT) had significantly fewer episodes of OM than others not taking SXT during the year-long trial. Multiple regression models revealed, however, that the influence of SXT on the number of OM episodes children experienced was relatively minor. The most important factor, regardless of study group, was exposure to potential pathogens, in terms of acquisition or reacquisition (ACQ) of S. pneumoniae and H. influenzae, as determined by serial nasopharyngeal cultures. The 19 children with no OM had significantly less exposure (3 ACQ/pt/yr) than the 31 children with ≥ 1 OM (4.5 ACQ/pt/yr; p < 0.001). It was also noted that 19/23 episodes of pneumococcal OM were associated with recent acquisition, rather than prolonged carriage, of the infecting strain, entirely consistent with our previously reported observations in a prospective study of pneumococcal carriage and infection. Except for the small influence of age at first OM, there was no reliable way to predict in advance which children were at greatest risk for OM. The usefulness of SXT prophylaxis is limited by the ability to select patients who are most likely to benefit. Consideration of SXT and other modes of OM prevention should take into account the variation in OM risk in terms of exposure to possible pathogens.