Illnesses in children infected with an adenovirus antigenically related to types 9 and 15.

During the investigation of an outbreak of febrile illness among children on a toddler ward within a hospital, a virus was recovered from specimens of the patients in HeLa cell cultures. The virus was found to have antigenic properties of both adenovirus types 9 and 15. The virus was neutralized by type 15 antiserum consistently. However, by hemagglutination characteristics and by hemagglutination-inhibition tests, the virus appeared to be type 9.