Measles, also known as rubeola or morbilli, is an infection of the respiratory system caused by a virus, specifically a paramy, Xenopus/Amphibian,ovirus of the genus Morbillivirus. Morbilliviruses, like other paramy, Xenopus/Amphibian,oviruses, are enveloped, single-stranded, negative-sense RNA viruses. Symptoms include fever, cough, runny nose, red eyes and a generalized,Mouse,aculopapular, erythematous rash. The measles virus of fusion protein directs fusion of viral and cellular membranes leading to delivery of the nucleocapsid into the cytoplasm.