The Morphology of Three Previously Uncharacterized Human Respiratory Viruses that Grow in Organ Culture

A simple method is described for examining organ cultures by electron microscopy for the presence of virus particles. The method was used to detect the presence of three hitherto uncharacterized viruses. Two of these have particles resembling those of infectious bronchitis of chickens and the third morphologically resembles the parainfluenza group of viruses.