A prospective, observational, epidemiological evaluation of the aetiology and antimicrobial susceptibility of acute otitis media in Saudi children younger than 5 years of age

Background: Information regarding acute otitis media (AOM) aetiology is important for developing effective vaccines. Here, bacterial aetiology and antimicrobial susceptibility of AOM were determined in young Saudi children. Methods: Children aged 3–60 months with a new episode of AOM, who had not received antibiotics or had received antibiotics for 48–72 h but remained symptomatic, were enrolled in this prospective, observational, epidemiological study in Riyadh. Middle ear fluid (MEF) samples were collected by tympanocentesis or from spontaneous otorrhea, and tested for the presence of Streptococcus pneumoniae, Haemophilus influenzae, Streptococcus pyogenes and Moraxella catarrhalis. Antimicrobial susceptibility of the identified pathogens was assessed using E-tests. Results: Between June 2009 and May 2011, 66 children were enrolled. S. pneumoniae was detected in 6 episodes and non-typeable H. influenzae (NTHi) in 8 episodes. Moreover, Staphylococcus aureus, which is an uncommon cause of AOM, was detected in 17 episodes. Pneumococcal serotypes were 7F (n = 2), 23F (n = 2), 19F (n = 1) and 15F (n = 1). Susceptibility to cefotaxime was observed in all pneumococcal and H. influenzae isolates, to cefuroxime in 4/6 pneumococcal and 8/8 H. influenzae isolates, and to penicillin in 5/6 pneumococcal isolates. Conclusions: S. pneumoniae and NTHi were major bacterial contributors for AOM in Saudi children.