Clinically-relevant assessment for the development of experimental OM as determined by video otoscopy and tympanometry.

Expanded study: Intranasal challenge of chinchillas with NTHI, M. catarrhalis and RSV resulted in clinical indicators of otitis media as determined by otoscopy and tympanometry. (A) A healthy chinchilla tympanic membrane (TM), with both the annulum (a) and the umbo of the malleus (U) labeled. (B) Seven days after M. catarrhalis challenge, erythema (arrow) was observed along the umbo, along with darkening of the TM. Panels C-E – TM 11, 14 and 17 days after M. catarrhalis challenge, respectively, erythema (arrows) was observed along the annulum, over the U and across the TM (*).