Infant girl covered with measles rash. Measles (medical names: rubeola, morbilli) is a highly infectious viral disease that mainly affects young children. Symptoms of cold and fever develop after an incubation period of 8-15 days. On the 3rd to 5th day the characteristic blotchy rash develops (initially behind the ears, then on face and rest of body), which last for 3 to 5 days. The patient remains infectious throughout this period. In most cases the symptoms subside, but the infant may be susceptible to pneumonia and infections of the middle ear. Complete recovery may take 2-4 weeks. Vaccination provides effective immunity against the disease.