The purpose of this study is to identify and characterize the bacteria causing acute otitis media episode in HIV-positive and HIV-negative children (>=3 months to <5 years) in South Africa. Middle ear fluid sampling either by tympanocentesis or by careful sampling of spontaneous otorrhoea will be done; nasopharyngeal aspirate and urine sample will also be collected from the subjects.

Inclusion Criteria:

Inclusion criteria for all subjects:

• Age: >= 3 months and < 5 years at the time of enrolment.
• 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.
• Subject will be included as a treatment failure case.
• Written informed consent obtained from parent or guardian prior to study start.

Inclusion criteria for HIV-positive subjects:

• Documented HIV-positive status as given in subject's medical records. or
• Subjects referred from paediatric HIV clinic.

Inclusion criteria for HIV-negative subjects (including presumed negative children)

• Children who have been tested HIV-negative.
• Children whose mothers volunteer to have tested HIV-negative whilst pregnant with the index case and the child is free to any World Health Organization Grade II stigmata of HIV/acquired immunodeficiency syndrome.
• Children who do not fulfil the World Health Organization staging for HIV infection / immunosuppression.

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 but excluding cotrimoxazole or isoniazid prophylaxis in HIV exposed children.
• Provision of antibiotic by paediatrician/ENT specialist at the enrolment visit prior to the sampling of the middle ear fluid or spontaneous Otorrhoea.
• Children on antibiotics for acute otitis media who are clinically improving.

Children aged >= 3 months and < 5 years seeking healthcare for the treatment of acute otitis media.