Abstract 1041 Poster Session IV, Tuesday, 5/4 (poster 174)

Introduction. Viral upper respiratory infections may alter Eustachian tube ventilatory function as evidenced by pressure changes in the middle ear. The temporal relationship between symptomatic upper respiratory illness and middle ear pressure in healthy school children was examined.

Method. Ninety-nine children (age 5-12) were followed prospectively prior to illness. At the time of a cold, an aspirate of nasopharyngeal secretion was obtained for viral and bacterial detection, and sequential tympanometric measurements (GSI™) were done each schoolday for two weeks. Quantitative bacterial culture was performed on agars selective for three otitis pathogens. Respiratory syncytial virus (RSV) was detected by immunoassay (Abbott Testpack®). Rhinovirus, adenovirus, influenza and parainfluenza virus will be isolated in tissue cultures; rhinovirus and coronavirus will also be detected by reverse transcriptase polymerase chain reaction (RT-PCR).

Results. Fifty-four children who developed a cold during September and October 1998 were studied None of the children developed clinical symptoms of otitis media or other illnesses which required medical attention. None of the children received antimicrobial treatment. During colds 28 (52%) had a least one abnormal tympanogram (underpressure below - 100 daPa or overpressure above 50 daPa); half of the 28 had 5 or more abnormal measurements. Abnormal tympanometry developed within the first week of illness in 22 (79%) of the 28 children. The frequency of abnormal tympanometry on each day was highest (40%) during the first five days of illness and gradually declined by the end of two weeks (22% during days 6, 7, 8, 9 and 12% on days 12, 13).

A bacterial pathogen in high titer (≥102 cfu/ml) was detected in nasopharyngeal secretions of 7 of 26 children with normal tympanometry (Branhamella catarrhalis in 5, Hemophilus influenzae in 2, Streptococcus pneumoniae in 0). Seven were positive for RSV. Similarly, pathogenic bacteria were detected in 7 of 28 children with abnormal tympanometry (B. catarrhalis in 3, H. influenzae in 1, S. pneumoniae in 3). Five were positive for RSV. Other respiratory viruses are being identified.

Conclusion. Negative middle ear pressure developed in over one-half of children during uncomplicated colds and resolved spontaneously by two weeks after onset. The presence of pathogenic bacteria in the nasopharyngeal secretion did not increase the risk of developing negative middle ear pressure.

This study was supported in part by a grant from Hoffmann-LaRoche, Nutley, NJ.