Gas Supply, Demand and Middle Ear Gas Balance: Specific Aim 2

The most well supported immediate cause of Otitis media (OM) is a pre-existing or concurrent viral upper respiratory tract infection (vURI). However, not all vURI episodes cause OM and a variety of predisposing factors has been suggested to explain this selectivity. Based on our preliminary work using a model of experimental viral infections in adults, we hypothesize that the constitutional efficiency of the Eustachian tube (ET) to supply the middle ear (ME) with gas and thereby stabilize ME pressure at near ambient is a primary risk factor for OM during vURI. Here, we test the hypothesis that constitutionally poorer ET function (F) predisposes to ME pathology during a vURI. Specifically, we will use ETF testing protocols relevant to the pressure-chamber to evaluate constitutional ETF in ≈ 160 susceptible, adult volunteers who will be exposed to rhinovirus as part of our funded study entitled "Social and Psychological Risks for Infectious Disease" (PI: S. Cohen, PI: CHP subcontract: WJ Doyle) and document the ETF and ME responses to infection over a 5-day post-exposure, cloister period.

Also, using protocols relevant to the pressure-chamber, we will evaluate constitutional ETF in 80 children who will be enrolled into our funded study entitled "Role of Virus and Genetic Susceptibility in Otitis Media" (PI: CM Alper) and followed for vURI and OM from October through April. From both data sets, we will extract measures of ETF efficiency and determine using logistic regression with appropriate control variables (e.g. demographic data etc) if a single or combination of ETF variables predicts an abnormal ME response in rhinovirus infected adults or OM during a rhinovirus cold in children.