The purpose of the study is to identify the bacterial aetiology of acute otitis media episodes in young children aged ≥ 3 months to < 5 years in Saudi Arabia.

Inclusion Criteria:

A child will be eligible for inclusion if he/she meets the following criteria:

• Age: ≥ 3 months and < 5 years at the time of enrolment. The subject becomes ineligible on the fifth birthday.
• Signs, symptoms, and conditions: i. One of the functional or general signs of otalgia (or its equivalent: irritability), conjunctivitis, fever AND EITHER ii. Paradise's criteria (bulging, diffused or localised inflamed tympanic membranes) OR iii. Spontaneous otorrhoea of less than 24 hours
• Onset of signs and symptoms of AOM within 72 hours prior to diagnosis of AOM by a physician. To be included as treatment failure, subjects must have then received antibiotic treatment from the physician, but remain symptomatic 48-72h after initiation of treatment
• Written informed consent obtained from parent or guardian prior to study start.

Exclusion Criteria:

The following criteria should be checked at the time of study entry. If any apply, the child must not be included in the study.

• Hospitalised during the diagnosis of AOM or during treatment,
• Otitis externa, or otitis media with effusion
• Presence of a transtympanic aerator
• Systemic antibiotic treatment received for a disease other than AOM in the 72 hours prior to enrolment,
• Receiving antimicrobial prophylaxis for recurrent AOM,
• Provision of antibiotic by paediatrician/ENT specialist at the enrolment visit, prior to the sampling
• Patients on antibiotics for AOM who are clinically improving.

Subjects aged ≥ 3 months and < 5 years of age, diagnosed as having AOM