Antibody response in experimental Haemophilus influenzae otitis media

Because Haemophilus influenzae is one of the most common pathogens in otitis media with effusion, we have investigated the antibody response in the serum and middle ear effusion (MEE) in nontypable H influenzae-induced experimental acute otitis media in the chinchilla, using an enzyme-linked immunosorbent assay. During acute otitis media, a reasonable antibody titer was observed: local antibody titers in the MEEs were equal to or greater than those of the serum samples for four of five MEE samples obtained at one week after inoculation. By two weeks, titers in both serum and MEE samples were increased significantly. However, the bacteria persisted in the middle ear cavity, even in the presence of increasing antibody titers, for up to five weeks after infection. The reason for this persistence of the bacteria in the middle ear is unknown.