Experimental Viral Infections of the Temporal Bone. I. Experimental Otitis Media Due to Vaccinia Virus in Hamsters

Clinical and pathologic studies of patients with smallpox suggest that conductive hearing loss is a frequent complication of smallpox and that it is due to otitis media. A possible experimental model for this hearing loss has been developed by study of the pathogenesis of acute vaccinia virus infections of hamster middle ears. Infant hamsters developed severe necrotic otitis media, and vaccinia viral antigen was demo onstrated by fluorescent antibody staining in large confluent areas of epithelial cells lining the middle ear. Juvenile hamsters developed a patchy, less severe infection of the middle ear, most of which was present along the tympanic membrane and mid-dle ear ossicles. Adult hamsters did not develop middle ear infection. These findings support the argument that variola (smallpox) virus can cause otitis media in humans and that viral infection of the middle ear may be the cause of hearing loss. Infection with variola (smallpox) virus results in considerable mortality and morbidity, and hearing loss is common in survivors [I, 2]. Con-ductive hearing loss was found in 26 % of pa