Key aspects linked to sample management and analysis were not met during feasibility assessment limiting the ability of the study to reach its objectives.

The purpose of this study is to identify and characterize the bacteria causing complicated Acute Otitis Media episode in children >= 3 months to < 5 years in Turkey.

Inclusion Criteria:

• Age: >= 3 months and < 5 years at the time they are seen by the paediatrician. The subject becomes ineligible on the fifth birthday.
• Signs, symptoms, and conditions:
• One of the functional or general signs of otalgia ,conjunctivitis, fever and either
• Paradise's criteria or
• Spontaneous otorrhoea of less than 24 hours.
• Subjects if classified as recurrent acute otitis media or treatment failure as described below:
• Recurrent acute otitis media: Defined as a subject who has an episode of acute otitis media representing the third new episode within the past 6 months, or the fourth new episode within the past year.
• Treatment failure: Defined as a subject who was diagnosed with acute otitis media and received antibiotic treatment from a physician, but is still symptomatic 48-72 hours after initiation of the treatment. As with other acute otitis media cases, the onset of signs or symptoms should have been within 72 hours prior to the initial visit to the physician.
• Written informed consent obtained from parent or guardian prior to study start.

Exclusion Criteria:

• Hospitalised during the diagnosis of acute otitis media or during treatment.
• Otitis externa, or otitis media with effusion.
• Presence of a transtympanic aerator.
• Systemic antibiotic treatment received for a disease other than acute otitis media in the 72 hours prior to enrolment.
• Receiving antimicrobial prophylaxis for recurrent acute otitis media.
• Provision of antibiotic by paediatrician at the enrolment visit prior to the sampling of the middle ear fluid or spontaneous otorrhoea.
• Patients that are on antibiotics for acute otitis media, and are clinically improving.

Subjects aged >= 3 months and < 5 years, diagnosed as having complicated acute otitis media on routine clinical care in the study hospitals.