Serologic Evidence of American Experience with Newborn Pneumonitis Virus (Type Sendai)

Abstract

The host range and growth characteristics of the Newborn Pneumonitis Virus (Type Sendai) have been studied. The hemagglutinin and serologic character have been examined and evidence is presented which supports the contention of the Japanese investigators that this is a hitherto undescribed virus. Evidence has also been found that an antigenic stimulus exists in the American population which gives rise to antibodies which react with the Sendai agent. This antigenic entity is widespread geographically and has been present at least since 1936. At the present, antibodies occur with high frequency (40 per cent) and the highest levels are present in the age group under 18 years. Isolation of the agent in our population has not been successful and only in a few instances could a serologic diagnosis be made of infection. The possible relation of the agent to the influenza group of viruses has been considered.