INCREASED SECRETORY CAPACITY OF THE MIDDLE-EAR MUCOSA AFTER ACUTE OTITIS-MEDIA CAUSED BY HAEMOPHILUS-INFLUENZAE TYPE-B

Secretory otitis media is associated with a highly increased goblet ce ll density of the middle ear mucosa. Previous studies have shown that a single episode of experimental acute otitis media caused by Streptoc occus pneumoniae or nontypeable Haemophilus influenzae is followed by increased goblet cell density for a period of at least 6 months. This condition may create a predisposition for subsequent development of se cretory otitis media. We inoculated the middle ears of 25 rats with ty pe B H. influenzae to determine the effect of the bacteria on mucosal secretory capacity. Five rats were euthanized 4, 8, 16, 60, and 180 da ys after inoculation, followed by dissection, staining, and whole-moun t embedding of the middle ear mucosa. The goblet cell density was dete rmined in 24 well-defined localities. Compared with that of 25 normal middle ears, the goblet cell density was significantly increased in al most all counting localities on all days of euthanasia. Thus increased goblet cell density and enlargement of mucosal areas containing goble t cells persisted for 6 months after the acute incident. Inoculation o f type B H. influenzae induced an increase of goblet cell density that was higher than the increase after inoculation of S. pneumoniae or no ntypeable H. influenzae. We conclude that experimental acute otitis me dia caused by type B H. influenzae is followed by a longstanding incre ase of mucosal secretory capacity, which is likely to induce a subsequ ent development of secretory otitis media.