The purpose of this study is to Evaluate Pathogens and Immunity to Acute Otitis Media in Healthy Children.

A prospective evaluation of bacterial pathogens Streptococcus. pneumoniae, Haemophilus influenzae, Moraxella. catarrhalis and Staphylococcus aureus and their antibiotic susceptibility when colonizing the nasopharynx and/or causing acute otitis media in the years 2015-2025. The goal will be to recruit children into a prospective group beginning at 6 months of age and followed to 36 months of age in suburban Rochester, New York. Nasopharyngeal and nasal wash samples will be obtained at each well child visit and at acute otitis media (AOM) episodes. Middle ear fluid will be obtained from every child with an acute otitis media episode who undergoes a tympanocentesis procedure. All of the nasopharyngeal and middle ear fluid samples collected will be tested by standard microbiologic techniques to identify the presence of 4 potential otopathogens (S. pneumoniae, H. influenzae, M. catarrhalis and S. aureus). All S. pneumoniae will undergo serotyping and antibiotic susceptibility testing. All samples that are culture negative will be evaluated with a multi-locus PCR test to examine for presence of potential otopathogens.

Inclusion Criteria:

Healthy Children:

• Male or female age greater than/equal to 6 months or less than/equal to 36 months old.
• Parent/guardian willing to bring to all study visits

Exclusion Criteria:

• Any major illness/condition that in investigator opinion would put subject at risk during study.
• Otorrhea or tympanostomy tubes present in either ear @ time of enrollment.
• Direct descendant of study site personnel.
• Subjects < 6 months old or >36 months old at the time of enrollment

Healthy 6-36 month old children or Acute Otitis Media diagnosed children >/= 6mo but \