Microbiology of otorrhea in children with tympanostomy tubes: implications for therapy

Based on the prevalence of children with tympanostomy tubes who develop otorrhea, an analysis was performed to identify specific prognostic indicators in this population to enable clinicians to determine the likelihood of specific pathogens and select the best empiric therapy.

Data from two multicenter clinical trials of ofloxacin otic solution 0.3% (OFLX) trials in pediatric patients 1-12 years of age were used to develop a statistical model to predict the likelihood of external auditory canal (EAC) or nasopharyngeal (NPG) pathogens. Data were available for 283 microbiologically evaluable patients. Potential indicators included subject age, season of enrollment, ear aspiration, cleaning, otorrhea, and granulation tissue. The model used a stepwise logistic regression analysis relating the occurrence of NPG or EAC pathogens to the potential prognostic indicators.

Among the total study population, 42.8 and 61.5% had NPG and EAC pathogens, respectively; 10.6% had both. The most frequently isolated valid pathogens were Streptococcus pneumoniae and Haemophilus influenzae. Significant prognostic indicators for NPG pathogens were subject age, season of enrollment, and presence of ear odor. Although these indicators were similar for EAC and NPG pathogens, the correlation was reversed, i.e. older subjects had EAC pathogens, and younger ones (< 2 years) had NPG pathogens; EAC pathogens were associated with presence of ear odor and NPG pathogens, with absence of ear odor.

A statistically and clinically valid model has been developed that has prognostic value for the clinician treating children with otorrhea and tympanostomy tubes and serves as an aid in the appropriate choice of empiric therapy.