Electron-microscopic study of measles virus in lymphocytes of affected children.

Two different types of inclusion bodies have been found by electron-microscopy in the cytoplasm of sectioned lymphocytes from children infected with measles.The first is tubular, 18 nm. internal diameter, embedded in osmiophilic material, and is found during the incubation period. It is not thought to be specific for measles, and is probably identical with structures recently reported in HEp-2 cell lines and tumour tissue.The second type is less obviously tubular and morphologically resembles measles nucleocapsid. This was found only after the rash had appeared.