Assessing the Baseline Burden of Otitis Media in Children 2 to 3 Years of Age for Estimating the Effecfs of 13-Valent Pneumococcal Conjugate Vaccine (pcv) on Otitis Media

Background: Otitis media is a common illness resulting in major resource use in children under-five years of age in high income countries. However, there is paucity of data on its epidemiology and clinical presentation in low-resource settings. We aimed to estimate the disease burden of otitis media in Cameroon and to determine the possible risk factors. Methods & Materials: A population-based cross-sectional descriptive prevalence study of otitis media (OM) was performed on randomly selected children aged 2 to 3 years in Yaounde, Cameroon. Two rounds of studies were planned: first for PCV-unvaccinated children between March and June in 2013, and the second round for PCV-vaccinated children 2 years later. OM burden was estimated using tympanometry and pneumatic otoscopy for otitis media with effusion (OME) and by parental questionnaires for acute otitis media (AOM). Here we report the baseline results from the first round. Results: Out of the 529 children enrolled, 427 were included in the final analyses and the rest were excluded due to indeterminate tympanogram data. Nonetheless, there were no major differences in the baseline characteristics between the two groups. Of those subjects, 84/427 (19.7%) were diagnosed with at least one form of otitis media or its complications. This consisted of 21 (4.9%) children with bilateral OME (i.e. OM in both ears) and 44 (10.3%) with unilateral OME. Based on otoscopy and parental questionnaire, an additional 14 (3.0%) children were diagnosed with AOM, 3 (0.7%) with unilateral CSOM based on inspection and 2 (0.5%) with unilateral ear perforations. No statistically significant relationship was found between OME and any of the predictor variables. However, multivariate logistic regression analysis identified a strong association between the existence of OME and one health outcome i.e. notification of any ear related problems/symptoms in the last 6 months prior to study period (Odds Ratio: OR = 2.5 and Confidence Interval: 95% CI = 1.3 – 5.0). Conclusion: The findings indicate that as many as every one in five children in our study population were affected by middle ear disease between the ages of 2 and 3 years.