980 INFECTIOUS DISEASES: THE ROLE OF INFLUENZA INDUCED POLYMORPHONUCLEAR LEUKOCYTE (PMN) DYSFUNCTION IN THE PATHOGENESIS OF PNEUMOCOCCAL OTITIS MEDIA

Abstract

Viral upper respiratory infection is often associated with acute otitis media suggesting that some respiratory virus compromise host defenses. We have shown that chinchillas inoculated intranasally with influenza A virus (INF) have subsequent depression of their PMN function. The role of PMN dysfunction in the pathogenesis of pneumococcal otitis media (PnOM) was studied using different intervals between intranasal pneumococcal (Pn) and INF inoculation. The incidence of PnOM was greatest when Pn was inoculated just prior to PMN dysfunction. Inoculation with Pn two days after INF produced PnOM in 7/10 chinchillas. Inoculation of Pn two days before INF, concurrent with INF and 12 days after INF caused PnOM in 12/36, 3/8 and 1/10 chinchillas, respectively. PnOM developed in 6/26 and 0/25 chinchillas inoculated with Pn or INF alone, respectively. Four through six days after INF inoculation, 13 chinchillas receiving either INF or INF + Pn had markedly depressed PMN chemiluminescence and chemotactic activity, while seven chinchillas receiving Pn alone had normal PMN function. PMN depression always preceeded clinical illness. Tympanoplasty tubes were placed in one ear of 38 chinchillas, and no difference was found in the incidence of PnOM in ventilated and non-ventilated ears. While eustachian tube obstruction contributes to the development of middle ear effusion, these results suggest that viral induced PMN dysfunction may also be important in the pathogenesis of PnOM.