Background: Acute otitis media (AOM) is a major health problem in young children. There is a general conception that AOM is a bacterial disease but with the availability of sensitive diagnostic methods, it has gradually become evident that viruses play an important role in the pathogenesis of AOM. Paired blood samples are seldom taken from infants although valuable information could be obtained by serological methods. During the recent Finnish Otitis Media (FinOM) Cohort Study, in addition to nasopharyngeal aspirates (NPA) and middle ear fluids (MEF), paired acute and convalescent serum samples were collected from children with AOM.
Objectives: To establish the diagnostic value of serological methods in etiological and epidemiological studies of AOM.
Study design: A complete set of NPA, MEF, and paired sera was collected during 447 events of AOM experienced by 179 children between 2 months and 2 years of age. Antigens of respiratory syncytial virus (RSV), adenoviruses, influenza A and B, and parainfluenza types 1-3 in NPAs and MEFs were detected by time-resolved fluoroimmunoassay (TR-FIA), and antibody titers were determined by complement fixation test (CFT) or by enzyme immunoassay.
Results: A total of 163 virus-positive events were identified. Of those, only 34 were positive by TR-FIA and by serology. From 48 events a positive result was obtained only by TR-FIA and from 81 only by serology.
Conclusion: Although serological methods are usually of little use in clinical practice, epidemiological studies clearly gain value if serology is included. The number of virus-positive findings dramatically increased by including serological tests in the diagnostic work-up of these AOM events.