Otitis Media in Children clinical trials

Microbiology of Otitis Media in Costarrican Children After PCV13 Introduction

Studies which describe the bacterial aetiology and antimicrobial susceptibility in AOM children in Latin America are scarce. Interestingly, when the MEF microbiology was analyzed among 1,108 children aged 2-92 months with OM between years 2002 and 2007, non-typable H. influenzae was the most common pathogen isolated from the MEF of children with a otitis media failing to appropriate antimicrobial therapy. PCV-7 (3 + 1 regimen) was introduced into the Costa Rican national immunization program in January 2009 and in August/September of 2011, it was changed for PCV 13 (-2+1 regimen). Following PCV-7 universal introduction in Costa Rica, between March of 2010 and January of 2011, MEF samples from Costa Rican children with OM, having received 0-4 PCV 7 vaccine doses, were obtained via tympanocentesis (88%) or from spontaneous otorrhoea (12%). It was interesting to observed that among the initial 134 OM episodes, the most common bacterial pathogen identified was H. influenzae (55%) followed by S. pneumoniae (31%) and that among the S. pneumoniae episodes, 55% were already non-PCV-7 serotypes and that 25% of these isolates were multi-drug resistant. The primary objectives of the study are to analyze the effect of early universal utilization of PCV-13 in Costa Rican children with the number of H. influenzae and PCV-13- S. pneumoniae positive MEF cultures by comparing the data collected prospectively and by the same group of investigators that have collected the original data since 1992, from children for the post-PCV-13 introduction with anonymised information collected retrospectively pre-PCV-7 data (1999-2004) during a transition period in which PCV-7 was used in only the private settings (2005-2008) and during universal use of PCV-7 (2009-September 2011).