Measles viruses. Coloured Transmission Electron Micrograph (TEM) of a section through a human cell infected with the measles virus. Measles (rubeola or morbilli) is an infectious viral disease spread by sneezed or coughed airborn droplets. At lower left are green viruses filling an area in the cell (brown). Viruses multiply in lymphatic cells. Measles mainly affects children, but can occur at any age, the adult form being more severe. One attack usually gives lifelong immunity. Flu-like symptoms develop accompanied by fever and a rash. Complications include chest infections, diarrhoea and vomiting. Vaccination against measles provides immunity. Magnification: x10,000 at 6x7cm size.